CONDENSATE REMOVAL DEVICE

BACKGROUND OF THE INVENTION

[0001] The present invention generally relates to condensate removal devices in piping systems, and more particularly to a condensate removal device for a steam piping system.

[0002] Steam is an efficient and widely used heat transfer medium for transporting energy. An unavoidable by-product when using steam is liquid condensate (i.e., water) that forms when heat is transferred away from steam along pipes or at heat exchangers. Basically, when the steam cools below a threshold temperature at a given pressure it becomes condensate. As a result, condensate collects inside pipes or other components, which significantly degrades system efficiency. In addition, condensate can cause a destructive water hammer, a shock wave that damages components and can cause serious injury to people nearby. Accordingly, condensate should be removed from steam systems as it forms .

[0003] ^" A steam trap is a mechanical device used to drain condensate while retaining or "trapping" steam. Traps are typically positioned at natural low points in steam systems where condensate collects or ahead of control valves where condensate could impede proper valve operation. Most traps operate using the inherent difference in density between liquid and gas to separate the fluids. Ideally, each trap should be capable of draining a mass flow, or load, of condensate that flows to its location in the steam system. Each trap should also be reliable in operation to avoid costly inefficiencies that arise when condensate collects or when live steam is released from a defective trap. Several types of steam traps are commonly available. Some are complex in design and subject to fail without frequent maintenance.

[0004] One type of trap that is economical and reliable is a fixed orifice trap. A relatively small hole or a tubular passageway in a trap permits condensate to drain through. These traps are comparatively inexpensive and there are no moving parts to corrode or fail . They are very effective in draining condensate while preventing release of live steam. The condensate flowing in a fixed orifice generally blocks entry of steam.

[0005] A drawback to fixed orifice traps is that they cannot accept large variation in condensate load. The diameter of the orifice is fixed, and therefore the capacity of the trap, which is proportional to area of the orifice and the flow velocity, is also substantially fixed. Thus, the orifice in the trap is sized to drain an expected load. The actual load, however, can increase by a factor of four or more if ambient temperature decreases, causing heat transfer rates from the steam to increase and causing formation of a larger quantity of condensate. In the past, this has been partially compensated for by over-sizing the orifice for the particular application.

[0006] An over-sized orifice not only passes more load, but possesses a valuable secondary benefit of a greater ability to pass solid debris. Small deposits of corrosion or other particulate matter within the steam system may become mixed with the condensate and can clog the trap. Solid particles are less likely to lodge in an orifice or passageway that is relatively larger. However, a trap having an orifice that is larger than needed for ordinary loads tends to permit release of live steam and, as a result, is inefficient.

[0007] A second type of trap is a thermodynamic or disk type trap. An obstruction comprising a flat disk is freely captured in the trap and is movable between a closed position in which the disk blocks flow of fluid through the ^" trap, and an open position in which the disk permits flow of fluid. The disk may cycle between open and closed

positions, and when in the open position the trap is capable of handling a greater quantity of condensate load than a fixed orifice trap. Condensate flow initially raises the disk open as it flows in. When steam arrives it changes the local pressure and lowers the disk, closing the trap, which stays closed as long as relatively higher pressure is maintained above the disk. At each cycle, there is an inherent time delay for closing the disk, as is common in thermodynamic traps, during which some live steam is released from the trap. So although the thermodynamic trap is beneficial in draining a large quantity of load, it has inherent inefficiency.

[0008] Another type of steam trap is a float type trap. In this type of trap, a float is disposed within an interior space of the trap for engaging and blocking an outlet port. As condensate buildups in the steam system, it collects in the interior space of the trap causing the float, which is buoyant, to lift off of the outlet port and allow condensate to flow out of the interior space of the trap through the outlet port. Once a sufficient amount of condensate has drained from the interior space of the trap, the float reengages and blocks the outlet port. The float moves in and out of engagement with the outlet port, as necessary, to allow collected condensate to drain from the interior space of the trap while preventing the exit of steam. The float is typically spherical and is free to move within the trap. Under certain transient conditions, the float can be violently moved within the trap, slamming into the walls and outlet port. Although, the ball is made of metal, it becomes heavily dented over time. The damaged float is less capable of making a seal with the outlet port, thereby greatly reducing its effectiveness, or rendering the float inoperable to close the outlet port.

[0009] Operating conditions, including pressure, temperature, condensate load, and amount of solid debris vary not only from one system to another but also from one

region of a system to other regions in the same system. Accordingly, different types of traps may be more appropriate for placement in certain areas of the steam system. Unfortunately, knowledge of operating conditions is uncertain, not easily predicted, and varies over time. Since typical steam traps are best suited for operating over only a small range of conditions, it is often not clear which type of trap is best suited for a given steam system or in a particular region of system. In practice, many steam system operators maintain a large and cumbersome inventory of several types of steam traps, and they choose one trap appropriate to estimated flow conditions. Operators may need to change steam traps because of altered or mistakenly estimated conditions . When an installed trap is removed and replaced, it often requires breaking a steam line, resulting in substantial downtime for the entire steam system. Moreover, maintaining an inventory of various types of traps that may or may not be used is expensive.

SUMMARY OF THE INVENTION

[0010] In one aspect, the present invention is directed to a condensate drain generally comprising a body defining an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate to enter into the interior space, and an outlet opening is in fluid communication with the interior space of the body for allowing condensate to exit the interior space. A float is disposed in the interior space for movement within the interior space relative to the body generally along a float axis between a closed position in which the float blocks fluid communication from the inlet opening to the outlet opening and an open position in which the float permits fluid communication ^" from ^"" the ^" inTet ^" opening to ^" the ^" outlet opening. The float is buoyant so that the float is moved to the open position by

condensate as condensate fills the interior space of the body. The body interior space and the float are sized and shaped so that the float is constrained to substantial alignment with the float axis.

[0011] In another aspect, the present invention is directed to a modular condensate drain generally comprising a body including a base adapted for connection to a steam piping system. A cap is cooperable with the base to define an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate from the piping system to enter into the interior space. A seat defines an outlet opening in fluid communication with the interior space of the body for allowing condensate to exit the interior space. A float is disposed in the interior space for movement within the interior space relative to the body between a closed position in which the float engages the seat and blocks fluid communication from the inlet opening to the outlet opening and an open position in which the float permits fluid communication from the inlet opening to the outlet opening. The float is buoyant so that the float is moved to the open position by condensate as condensate fills the interior space of the body. The cap is constructed for removable attachment to the base and the seat is constructed for removable attachment to the body for selective replacement of the seat.

[0012] In still another aspect, the present invention is directed to a condensate drain generally comprising a body defining an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate to enter into the interior space. An outlet opening is in fluid communication with the interior space of the body for allowing condensate to exit the interior space . A moveable member is located in the interior space and moveable therein between an open position in which the movable member is spaced from the

outlet opening to permit a greater flow from the inlet opening to the outlet opening, and a closed position in which the moveable member is closer to the outlet opening and permits a lesser flow from the inlet opening to the outlet opening. The moveable member has a passage therein extending from the interior space of the body to the outlet opening. The passage includes at least a portion of smaller diameter that the outlet opening for passing condensate out of the interior space and blocking steam from passing out to the interior space when the movable member is closed.

[0013] In still a further aspect, the present invention is directed to a steam restricter that is adapted to be retrofitted into an existing steam trap having a chamber, an inlet for admitting steam and condensate into the chamber, and a drain for draining condensate from the chamber to a condensate return. The steam restricter generally comprises a body having an inlet passage positioned for opening to the chamber of the steam trap when installed in the steam trap and a cavity in the body, the inlet passage in the body extending to the cavity. A drain outlet passage extends from the cavity for passing condensate from the cavity to the drain of the steam trap when installed therein. A thermodynamic stop disk is disposed in the cavity for movement in the cavity relative to the body between an open position in which the stop disk permits fluid communication through the cavity from the inlet passage to the outlet passage and a closed position in which the stop disk blocks communication from the inlet passage to the outlet passage. A mating base is sized and shaped for connection to the drain of the steam trap so that passage of fluid in the steam trap to the drain is blocked except through the steam restricter when installed in the steam trap. The outlet passage extends through the mating base and opens into the steam trap drain when installed in the steam trap.

[0014] in yet a further aspect, the present invention is directed to a steam restricter capable of handling variable condensate loads and is compact for installation in small spaces. The steam restricter generally comprises a body having a central axis and an inlet passage including first and second inlet passage members for receiving steam and condensate into the body and a cavity in the body. The second inlet passage member extends parallel to the central axis of the body to a mouth where the second inlet passage member opens into the cavity. A drain outlet passage includes a drain passage member adapted for fluid communication with the cavity. The drain passage member extends parallel to the central axis of the body to a port. The cavity and port are at least partially in registration with each other along the central axis of the body. A thermodynamic stop disk is disposed in the cavity for movement relative to the body between an open position in which the stop disk permits fluid communication through the cavity from the second inlet passage member to the drain passage member and a closed position in which the stop disk blocks fluid communication from the second inlet passage member to the drain passage member.

[0015] In still yet another aspect, the present invention is directed to a condensate drain generally comprising a body defining an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate to enter into the interior space. An outlet opening is in fluid communication with the interior space of the body for allowing condensate to exit the interior space. A failure warning system includes a passageway extending through the body for fluidly communicating the interior space of the body with a location outside of the body. A contact member is moveable between a blocking position wherein fluid is blocked from passing through the passageway and an unblocking position wherein fluid is free to pass through

the passageway. A temperature responsive member is connected to the contact member for moving the contact member between the blocking and unblocking positions in response to temperature changes within the interior space of the body.

[0016] In a further aspect, the present invention is directed to a condensate drain generally comprising a body adapted for connection to a steam piping system and defining an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate from the piping system to enter into the interior space. A seat defines an outlet opening in fluid communication with the interior space of the body for allowing condensate to exit the interior space. A float is disposed in the interior space for movement within the interior space relative to the body between a closed position in which the float engages the seat and blocks fluid communication from the inlet opening to the outlet opening and an open position in which the float permits fluid communication from the inlet opening to the outlet opening. The float is buoyant so that the float is moved to the open position by condensate as condensate fills the interior space of the body. A guide pin is attached to the seat. The guide pin is generally aligned with a longitudinal axis of the body and engageable with the float to guide its movement .

[0017] In still another aspect, the present invention is directed to a condensate drain generally comprising a body adapted for connection to a steam piping system and defining an interior space. An inlet opening is in fluid communication with the interior space of the body for allowing condensate from the piping system to enter into the interior space. A seat defines an outlet opening in fluid communication with the interior space of the body for allowing condensate to exit the interior space. The outlet opening is located eccentrically. A float is disposed in

the interior space for movement within the interior space relative to the body between a closed position in which the float engages the seat and blocks fluid communication from the inlet opening to the outlet opening and an open position in which the float permits fluid communication from the inlet opening to the outlet opening. The float is buoyant so that the float is moved to the open position by condensate as condensate fills the interior space of the body.

[0018] In yet another aspect, the present invention is directed to a steam restricter having a chamber, an inlet for admitting steam and condensate into the chamber and a drain for draining condensate from the chamber to a condensate return. The steam restricter generally comprises a body having an inlet passage positioned for opening to the chamber of the steam trap when installed in the steam trap. A cavity is in the body and the inlet passage in the body extends to the cavity. A drain outlet passage extends from the cavity for passing condensate from the cavity to the drain of the steam trap when installed therein. A thermodynamic stop disk is disposed in the cavity for movement in the cavity relative to the body between an open position in which the stop disk permits fluid communication through the cavity from the inlet passage to the outlet passage and a closed position in which the stop disk blocks communication from the inlet passage to the outlet passage. The stop disk has a recess in fluid communication with the inlet passage, at least a portion of the recess having a chamfered edge.

[0019] Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 is a perspective of a condensate drain of the present invention;

[0021] FIG. 2 is an exploded perspective of the condensate drain shown in FIG. 1;

[0022] FIG. 3 is a section taken on line 3-3 of Fig.l;

[0023] FIG. 4 is a section similar to FIG. 3 with a float moved to an opened position;

[0024] FIG. 5A is a vertical section of a condensate drain having another configuration;

[0025] FIG. 5B is a vertical section similar to FIG. 5A with a float moved to an opened position;

[0026] FIG. 5C is a vertical section similar to Fig. 5A with a float moved to an overflow opened position;

[0027] FIG. 6 is an enlarged perspective of a valve shown in FIG. 5;

[0028] FIG. 7 is a top plan view of a base of the drain showing a baffle;

[0029] FIG. 8A is a vertical section of a condensate drain having yet another configuration including a guide pin;

[0030] FIG. 8B is an enlarged fragment indicated on Fig. 8;

[0031] FIG. 8C is a vertical section similar to FIG. 8A with a float moved to an opened position;

[0032] FIG. 9A is a vertical section of a condensate drain having still another configuration and showing a bimetallic disk in an open position and a float in a closed position;

[0033] FIG. 9B is a vertical section similar to FIG. 9A with the bimetallic disk and the float in a closed position;

[0034] FIG. 9C is a vertical section similar to FIGS. 9A and 9B with the bimetallic disk in the closed position and the float in the opened position;

[0035] FIG. 10 is a top plan view of a base shown in FIGS. 9A-9C with a portion of a bimetallic disk broken away to show a failure warning system;

[0036] FIG. HA is a vertical section of a condensate drain having still yet another configuration including a guide pin;

[0037] FIG. HB is a vertical section similar to FIG. HA with a float moved to an opened position;

[0038] FIG. 12A is a vertical section of a condensate drain having a second embodiment including a bimetallic disk and a flow restricter connected to the disk;

[0039] FIG. 12B is a vertical section similar to FIG. 12A with the bimetallic disk moved to a closed position;

[0040] FIG. 12C is a vertical section similar to FIGS. 12A and 12B with the bimetallic disk in the closed position and the flow restrictor moved to an opened position;

[0041] FIG. 13A is a vertical section of a condensate drain having a third embodiment including a bimetallic disk and a labyrinthine flow restricter connected to the disk;

[0042] FIG. 13B is a vertical section similar to FIG. 13A with the bimetallic disk moved to a closed position;

[0043] FIG. 14 is an enlarged perspective of a plug of the labyrinthine flow restrictor shown in FIGS. 13A and 13B;

[0044] FIG. 15A is a vertical section of a condensate drain of a fourth embodiment including a bimetallic disk and a fixed orifice flow restricter connected to the disk;

[0045] FIG. 15B is a vertical section similar to FIG. 15A with the bimetallic disk moved to a closed position;

[0046] FIG. 16A is a vertical section of a condensate drain of a fifth embodiment including a thermostatic bellows element and a labyrinthine flow restricter;

[0047] FIG. 16B is a vertical section similar to FIG. 16A with the thermostatic bellows element moved to a retracted position;

[0048] FIG. 17A is a vertical section of a condensate drain similar to FIGS. 16A and 16B but including a. fixe_d orifice flow restricter;

[0049] FIG. 17B is a vertical section similar to FIG. 17A with the thermostatic bellows element moved to a retracted position;

[0050] FIG. 18A is a vertical section of a condensate drain similar to FIGS. 16A-17B but including a thermodynamic flow restricter;

[0051] FIG. 18B is a vertical section similar to FIG. 18A with the flow restricter moved to an open position;

[0052] FIG. 18C is a vertical section similar to FIG. 18A with the thermostatic bellows element moved to a retracted position;

[0053] FIG. 18D is a vertical section of a condensate drain similar to FIG. 18A but including a thermodynamic flow restricter affixed to a thermostatic bellows element so that the restricter moves with the bellow element;

[0054] FIG. 18E is a vertical section similar to FIG. 18D with the thermostatic bellows element moved to a retracted position;

[0055] FIG. 19A is a vertical section of a condensate drain similar to FIGS. 16A-18C but including a float;

[0056] FIG. 19B is a vertical section similar to FIG. 19A with the float moved to an open position;

[0057] FIG. 19C is a vertical section similar to FIG. 19A with the thermostatic bellows element moved to a retracted position;

[0058] FIG. 19D is a vertical section of a condensate drain similar to FIG. 19A but including a seat extending above a thermostatic bellow element for engagement with a float;

[0059] FIG. 19E is a vertical section similar to FIG. 19D with the thermostatic bellows element moved to a retracted position;

[0060] FIG. 20 is a schematic of a forced air steam heater;

[0061] FIG. 21 is a schematic cross-section of the heater of FIG. 20;

[0062] FIG. 22 is a cross section of a steam trap including a steam restricter of the present invention;

[0063] FIG. 23 is an exploded perspective of the steam restricter removed from the steam trap,-

[0064] FIG. 24 is a vertical section of the steam restricter;

[0065] FIG. 25 is an exploded vertical section of the steam restricter;

[0066] FIG. 26 is a cross-section taken along the plane including line 26-26 of FIG. 24;

[0067] FIG. 27 is a side elevation of a cylindrical portion of a body of the steam restricter;

[0068] FIG. 28 is a top view of the cylindrical portion;

[0069] FIG. 29 is a bottom view of the cylindrical portion,-

[0070] FIG. 30 is a perspective of a steam restricter retrofit kit;

[0071] FIG. 31 is a vertical section of a second embodiment of the steam restricter; and

[0072] FIG. 32 is a vertical section of a steam restricter similar to FIG. 31 but having a different embodiment of a thermodynamic stop disk.

[0073] Corresponding reference characters indicate corresponding parts throughout the drawings .

DETAILED DESCRIPTION OF THE INVENTION

[0074] Referring now to the drawings and in particular to Fig. 1, a condensate drain is indicated generally at 10. The drain 10 can be used to effectively remove condensate from a variety of gas and liquid fluid systems, in which condensate collects. For example and as described herein, the drain 10 can be used in a steam

system (not shown) as a steam trap. That is, the drain 10 is design to allow condensate to pass through the drain so that it can be removed from the steam system while preventing steam from exiting the system.

E0075] A necessary consequence of operating a steam system is the production of condensate. While the quantity of condensate produced in some systems or regions of a single system may be somewhat consistent, often times there are large variations in the quantity of condensate produced over time. For example, a drop in ambient temperature may result in a larger quantity of condensate being produced whereas a rise in ambient temperature may result in a smaller quantity of condensate being produced. Moreover, large quantities of condensate and air may be present during the startup of the steam system after a period of down time.

[0076] The drain 10 is modular so that it can be configured to handle large quantities of condensate, small quantities of condensate, or fluctuating quantities of condensate. Thus, the drain 10 of the present invention can be easily configured as described below to accommodate many types of condensate conditions. Moreover, the modular components of the drain 10 can be nondestructively removed, installed, or replaced while the drain is connected to the steam system. The steam system piping does not need to be disassembled in anyway to change the configuration of the modular drain 10.

[0077] As shown in Figures 1 and 2, the drain 10 includes a generally tubular body comprising a hexagonal base, indicated generally at 12, and a cylindrical cap, indicated generally at 14, having a threaded connection to the base. As a result of the threaded connection, the cap 14 can be removed from the base 12 by unscrewing the cap, and can be reconnected by screwing the cap back onto the ^" base. ^" Other structure for reϊeasably connecting the cap to the base may be used without departing from the scope of

the present invention. In the illustrated embodiment, the base 12 and cap 14 form a body of the drain. The drain 10 is adapted for installation in the steam system at a location where condensate is desired to be removed, such as at one of several low elevation points in the system or ahead of a flow control valve.

[0078] The drain 10, as illustrated in Fig. 1, is configured to be installed in the steam system with a longitudinal axis LA of the body of the drain 10 oriented generally vertically so that the cap 14 is positioned above the base 12. As shown in Fig. 3, the base 12 includes an internally threaded entry passage 16 and an internally threaded exit passage 18. The entry passage 16 is used to connect the drain 10 to pipes of the steam system (not shown) , and the exit passage 18 is used to connect the drain 10 to a condensate return pipe (not shown) .

[0079] The base 12 also includes an inlet opening 20 to provide fluid communication between entry passage 16 and an interior space 15 of the drain 10. Both steam and condensate, as well as noncondensibles, can enter the inlet opening 20. The interior space 15 of the drain 10 is defined by the base 12 and the cap 14. It will be understood that the number of components defining the interior space 15 may be other than two within the scope of the present invention. Thus, the interior space 15 of the drain 10 is easily assessable by unscrewing the cap 14 from the base 12. Accordingly, the interior space 15 of the drain 10 can be accessed without disassembling any of the piping of the steam system

[0080] The base 12 further includes an outlet opening 24 that functions as an exit from the interior space 15 of the drain 10 for condensate that is removed from the steam system (Fig. 4) . In other words, the outlet opening 24 provides a fluid passage between the interior space 15 of ^" the drain 10 and the exit passage 18. As a result, condensate that passes through the outlet opening 24 to the

exit passage 18 flows into the return pipe which in turn delivers condensate to a suitable discharge location, such as a boiler where the water may be re-used. Condensate entering the drain 10 flows from left to right (as viewed) through the drain as indicated by arrows in Fig. 4. Steam is prevented from exiting the interior space 15 of the drain as described in more detail below.

[0081] Referring to Fig. 2, the outlet opening 24 is formed in a flow regulator 26 having a seat 28 and a narrower threaded shaft 30 extending outward from the seat.

As shown in Figs. 3 and 4, the threaded shaft 30 is threadedly connected to an internally threaded socket 32 formed in the base 12. Thus, the flow regulator 26 can be readily and nondestructively removed from the base 12 by unscrewing the regulator from the base and can be reconnected by screwing the regulator into the base . In that regard, the seat 28 has the shape of a hexagonal bolt head for facilitating driving engagement by a socket wrench or the like.

[0082] As a result, the flow regulator 26 can be easily removed for maintenance (i.e., cleaning) or replaced with a regulator having a different size outlet opening. Thus, the flow capacity of the outlet opening 24 can be selectively altered by replacing the flow regulator 26 with a different flow regulator having a larger or a smaller outlet opening to match the condensate production of the system or region of the system. Accordingly, if the flow capacity of the outlet opening needs to be increased, the flow regulator 26 is replaced with a flow regulator having a larger opening. As illustrated in Fig. 2, for example, a flow regulator 26' similar to flow regulator 26 but having a larger outlet opening 24 ' can be used to increase the flow capacity of the outlet opening. On the other hand, if the flow capacity of the outlet opening needs to be decreased^ the flow regulator is replaced with a flow regulator having a smaller opening, such as a flow

regulator 26' ' shown in Fig. 2 that has a smaller outlet opening 24 ' ' than the previously described flow regulators 26, 26'. It is understood that flow regulators having openings different than those illustrated can be used.

[0083] A mesh screen 34 is disposed within the base 12 for filtering any particles (e.g., pieces of rust) that could lodge in the drain 10 and clog its operation. The screen 34 is interposed between the inlet opening 20 and the outlet opening 24 so that any condensate entering the drain 10 is filtered before it enters into the interior space 15 of the drain. As shown in Fig. 2, the mesh screen 34 is generally annular and has a central aperture 36. The screen 34 is support in the base 12 by two, spaced apart annular ledges 38, 40 formed in the base. The first annular ledge 38 is located adjacent the socket 32 formed in the base 12. The aperture 36 in the screen aligns with the socket 32 for allowing the shaft 30 of the flow regulator 26 to extend through the aperture and be threaded engagement with the socket. An outer edge of the screen 34 is support by second annular ledge 40 spaced from the first annular ledge 38. The seat 28 of the flow regulator 26 clamps the screen 34 against the first annular ledge 38 to hold the screen 34 in place. The screen 34 can be removed for cleaning or replacement by removing the cap 14 and unscrewing the flow regulator 26 from the base socket 32. Once the flow regulator 26 is removed, the screen 34 can be lifted out of the base 12.

[0084] The screen 34 in the illustrated configuration comprises a thirty mesh stainless steel wire cloth. But it is understood that the screen could be formed from other materials besides stainless steel or have other mesh sizes (e.g., 40 mesh) . Particularly, it is understood that the screen 34 can be readily changed and/or replaced as warranted by the steam system. In other words, the screen 34 is selected from a group of screens to match the specific criteria of the steam system.

[0085] Referring now to Figs. 2-4, a float 42 is disposed in the interior space 15 of the drain 10 for movement between a closed position in which the float blocks fluid communication from the inlet opening 20 to the outlet opening 24 (Fig. 3) , and an open position in which the float permits fluid communication from the inlet opening to the outlet opening (Fig. 4) . The float 42 is free of any fixed connection to the base 12 or cap 14. The float 42 includes an engagement portion 44 adapted for engagement with the seat 28 of the flow regulator 26 to block fluid communication between the interior space 15 of the drain 10 and the outlet opening 24. The seat 28 of the flow regulator 26 has a width that is substantially larger than the width of the engagement portion 44. As a result, the float 42 can move radially with respect to the longitudinal axis LA of the drain 10 and the engagement portion 44 will still contact the seat 28.

[0086] The float 42 is buoyant so that as condensate fills the interior space 15 of the drain the float rises (Fig. 4) . As a result, the engagement portion 44 is raised off of the seat 28 of the flow regulator 26. In other words, the float 42 is moved to the open position. Once in the open position, condensate exits the interior space 15 of the drain 10 through the relatively large outlet opening 24 to the exit passage 18. As the condensate level in the interior space 15 of the drain 10 is lowered by condensate flowing out of the outlet opening 24, the float 42 lowers until the engagement portion 44 reengages with the seat 28 of the flow regulator 26 (Fig. 2) . Thus, the float 42 resumes the closed position blocking condensate and/or steam from exiting the interior space 15 of the drain 10.

[0087] Referring again to Fig. 3 and 4, the portion of the interior space 15 of the drain 10 defined by the cap 14 is sized and shaped for supporting the float 42 from canting with respect to the cap as the float moves between the opened and closed positions. Stated another way, the

cap 14 and float 42 are sized and arranged so that the cap constrains the float to move substantially along the longitudinal axis LA. The float 42 is maintained in this orientation so that it cannot rotate about an axis perpendicular to the axis LA so that only the engagement portion 44 ever engages the seat 28 in the closed position of the float.

[0088] The engagement portion 44 extends axially outwardly from the float 42 and provides a portion of the float adapted for striking the seat 28 of the flow regulator 26. The engagement portion 44 is robust so that it can withstand the harsh environment to which it is subjected. For example, one suitable material for both the seat 28 and the engagement portion 44 is hardened stainless steel, such as 300 series stainless steels (e.g., 303, 304, 316) . In many steam systems, the float 42 is subjected to high pressure differentials that results in the float slamming against the seat 28 or other internal component of the drain. The engagement portion 44 of the present drain 10 is robust enough to withstand being repeatedly, forcefully struck against the seat 28 of the flow regulator 26 or other component of the drain.

[0089] Still referring to Figs. 3 and 4, the float 42 also includes a central passage 46 that extends completely through the center of the float. Accordingly, condensate that forms above the float 42 can flow downward through the central passage 46 to the outlet opening 24 even when the float is in its closed position. The engagement portion 44 of the float 42 has a central orifice 48 in fluid communication with the central passage 46 in the float and lateral orifices 50 in connection with the central orifice.

The lateral orifices 50 and central passage 46 are in fluid communication with a small diameter bleed 51 to provide for a bleed flow of condensate out the drain 10 when the float 42 is closed7 Because of the pressure drop of fluid passing out of the central passage 48 to the

outlet opening 24, the lateral orifices 50 and central passage 48 are generally filled with water that blocks escape of steam.

[0090] The drain 10 of the present invention is constructed of a material suitable for installation in high pressure and temperature steam systems. In practice, stainless steel has been effectively used in constructing each component of the drain. However, elements made of other materials do not depart from the scope of this invention.

[0091] Figs. 5A-5C show a condensate drain 110 similar to the condensate drain 10 shown in Figs. 1-4. Components of the drain 110 corresponding to the components of the drain 10 will be given the same reference numeral, plus "100". The drain 110, like the previous described drain 10, includes a hexagonal base 112 and a cylindrical cap 114 threadedly connected to the base. The base 112 and cap 114 cooperate to define an interior space 115 of the drain 110. Internally threaded entry passage 116 and exit passage 118 in the base 112 can be used to connect the drain 110 to pipes of a steam system and a return pipe, respectively. The base 112 also includes an inlet opening 120 for providing fluid communication between the steam pipes connected to the entry passage 116 and the interior space 115 of the drain 110. A mesh screen 134 is positioned adjacent the inlet opening 120 so that any condensate entering the drain 110 is filtered before it enters into the interior space 115 of the drain. The mesh screen 134 is support in the base 112 in the same manner as described for screen 34 of drain 10.

[0092] The base 112 further includes an outlet opening 124 and bleed opening 125 that function as exits from the interior space 115 of the drain 110 for condensate. In the illustrated configuration, the outlet opening 124 has a larger diameter than the bleed opening 125. Both the outlet and bleed openings 124, 125 are formed in a flow

regulator 126 having a seat 128 and a threaded shaft 130 extending outward from the seat for threadedly connecting to the socket 132 formed in the base 112. Thus, the flow regulator 126 can be easily removed for maintenance (i.e., cleaning) or replaced with a regulator having different size openings or more or fewer openings. Thus, the flow capacity through the flow regulator 126 can be selectively altered by replacing the flow regulator 126.

[0093] A float 142 with an engagement portion 144 and a central passage 146 is disposed free of fixed connection to the drain 110 in the interior space 115 of the drain 110 for movement between a closed position in which the float blocks fluid communication from the inlet opening 120 to the outlet opening 124 (Fig. 5A) , and an open position in which the float permits fluid communication from the inlet opening to the outlet opening (Figs. 5B and 5C). The float 142 is substantially the same as the float 42 described above and therefore is not described in detail.

[0094] In this configuration, however, a coil spring 156 biases the float 142 toward the open position so that when the steam system is started any air or other noncondensibles within the system can exit through the outlet opening 124. The pressure of the steam within the system is sufficient to overcome the bias of the spring 156 and move the float 142 to the closed position thereby inhibiting steam from exiting the drain 110.

[0095] Moreover, the engagement portion 144 includes an annular channel 152 for allowing fluid communication between lateral orifices 150 and a central orifice 148 and the bleed opening 125. The annular channel 152 is in continuous fluid communication with the bleed opening 125.

This arrangement works well in systems that produce, at least in certain periods of operation, a relatively constant condensate load by allowing condensate to exit the interior space 115 of the drain 110 without movement of the float 142.

[0096] As shown in Figs. 5A-5C and 7, the drain 110 further includes a baffle 121 located adjacent the inlet opening 120 for reducing the force at which condensate enters the interior space 115 of the drain 110. The baffle 121 minimizes damage to the drain 110 (and in particular to the float 142) caused by the high pressures under which some steam systems operate. In some systems, slugs of condensate forcefully enter the interior space 115 of the drain 110 subjecting the drain components to severe stresses that could result in damage. The baffle 121 absorbs the impact and laterally deflects the condensate as it enters into the interior space 115 of the drain 100 thereby preventing the drain components from being damaged.

[0097] In the illustrated configuration, the baffle 121 is a rectangular shaped plate that extends over and is spaced above the inlet opening 120. As a result, any condensate entering the interior space 115 of the drain 110 has to flow around the baffle 121. The baffle 121 includes an aperture 123 sized and shaped for aligning with the socket 132 in the base 112. The baffle 121 rests on a screen 134 and is secured in the base 112 by the flow regulator 126. The baffle 121 can be removed by unscrewing the flow regulator 126 from the socket 132. Thus, the baffle 121 can be added or removed from the drain 110 after the drain has been installed in the steam system. While the illustrated baffle 121 is shown is being rectangular, it is understood that the baffle can have different shapes (e.g., circular, square, hexagonal). A baffle could be symmetrical about the longitudinal axis LA of the drain 110.

[0098] With reference to Figs. 5A-6, the drain 110 also includes an overflow opening 160 (broadly, "a second outlet opening") located in a top of the cap 114. The overflow opening 160 provides an overflow in the event condensate comes in more rapidly than can be drained through the outlet opening 124 and the interior space 115

is filled with condensate. A valve, referred to generally at 170, is mounted in the top of the cap 114 to normally- block flow through the overflow opening 160. The valve 170 includes a tube 172 with external threads 174 for receiving a nut 176 for securing the valve to the cap 114. The nut 176 tightens against an exterior surface of the cap 114. The valve 170 further includes a shoulder 178 connected to the tube 172. The shoulder 178 engages an interior surface of the cap 114 and cooperates with the nut 176 for mounting the valve 170 to the cap. Extending outwardly from the shoulder 178 is a pair of arms 180 having openings 182. Each of the openings 182 pivotally receives a link 184. The links use the portions of the arms 180 adjacent the openings 182 through which they extend as respective fulcrums for pivoting up and down. A stop 186, which can block fluid communication between the overflow opening 160 and the interior space 115 of the drain 110, is attached to each of the links 184 by pin 188.

[0099] As a result, the stop 186 can be moved between a blocking position wherein the stop engages the shoulder 178 and blocks fluid communication between the interior space 175 of the drain 110 and the overflow opening 160 (Figs. 5A and 5B), and a non-blocking position wherein the stop is spaced from the shoulder thereby allowing fluid communication between the interior space of the drain and the overflow opening (Fig. 5C) . It will be appreciated that the stop 186 blocks the overflow opening 160 even when the float 142 is in a "normal" open position as shown in Fig. 5B. However in the event condensate fills the interior space 115 of the drain 110, the float 142 rises in the condensate thereby causing a free end of the links 184 to also rise, as shown in Fig. 5C. Raising the free end of links 184 causing the links to pivot about the opening 182 in the arms 180 such that the links assume a more ^" horizontal positron. As a result of the pin connection between the links 184 and the stop 186, the stop is moved

to its non-blocking position. With the stop 186 in its non-blocking position, condensate can flow out of the interior space 115 of the drain through the overflow opening 160. It is understood that the stop 186 can be moved by the float 142 in different ways than what is illustrated herein. For example, four links, each spaced 90° apart, can be used instead of the two links 184 shown in the illustrated configuration, which are spaced approximately 180° apart. The use of four links would increase the leverage of the links thereby allowing movement of a larger stop, which allows for a larger overflow opening.

[00100] The valve 170 and thereby the overflow opening 160 can be installed in the drain 110 by replacing a cap without a valve (e.g., cap 14) with a cap having a valve (e.g., cap 114) . Another way to install the valve in the cap is to drill a hole in the cap, slide the tube 172 of the valve through the hole so that the shoulder 178 engages the interior surface of the cap, and use the nut 176 to secure the valve to the cap. Either way, the valve can be installed in an existing system without disassembling any pipes in the steam system.

[00101] Figs. 8A- 8C show a drain 210 having yet another configuration. This drain 210 configuration is substantially similar to the drain 10 of Figs 1-4. Parts of the drain 210 corresponding to parts of the drain 10 will be given the same reference numeral, plus "200". In this configuration, however, a guide pin 290 extends downward from an upper, interior surface of a cap 214 and is configured to be received in a central passage 246 in a float 242 for orienting the float, and preventing the float from canting. It is noted that although the pin 290 restrains relative movement of the float 242 with respect to the drain 210, the float remains free of any fixed connection. The guide pin 290 in the illustrated configuration has a generally circular cross-section but it

is understood that the guide pin could have other cross- section (e.g., star, square, hexagonal).

[00102] Moreover, an engagement portion 244 of the float 242 includes a bleed port 251, which is in continuous fluid communication with an outlet opening 224 (Fig. 8A) . The bleed port 251 is provided for systems that produce a relatively constant condensate load. Thus, the condensate can exit an interior space 215 of the drain 210 without movement of the float 242. The bleed port 251 can have various sizes to accommodate various condensate loads. In addition, the float 242 having engagement portion 244 with the bleed port 251 can be replaced with a float 242 having an engagement portion with different size bleed port or no bleed port.

[00103] Figs. 9A-10 show a drain 310 having still another configuration that is substantially similar to the drain 110 of Figs 5-7. Components of the drain 310 corresponding to the components of the drain 110 have been given the same reference numeral, plus "200". In this configuration, however, a bimetallic disk 357 is used to bias a float 342 toward an open position upon system startup instead of a spring as was shown in Fig. 5. Cooler temperatures, such as when the steam system is inactive, cause the bimetallic disk 357 to assume an open position (Fig. 9A) . As a result, large amounts of condensate that might be present during system start can flow through an outlet opening 324 in a flow regulator 326. When steam enters an interior space 315 of the drain 310, the disk 357 is heated and snaps to the closed position of the disk as a result of the effect of the higher temperature of the steam on the disk caused by its bimetallic structure (Fig. 9B and 9C) .

[00104] The bimetallic disk 357 is generally circular and its perimeter edge rests on ribs 359 formed in a base 312 of ^" the drain. A retaining spring 361 cooperates with the ribs 359 for holding the bimetallic disk 357 in place.

The bimetallic disk 357 has a contact 311 having a generally flat upper surface 311A, a generally flat lower surface 3HB, and a central opening 3HC extending through the contact from the upper surface to the lower surface . In the illustrated configuration, the contact 311 is formed as two pieces secured (i.e., snapped) together. But it is understood that the contact 311 can be formed as a single piece.

[00105] When the bimetallic disk 357 is in its closed position, the lower surface 311B of the contact 311 engages a seat 328 of the flow regulator 326 and blocks condensate and/or steam from flowing through a passage 371 and an annular channel 373 associated with a failure warning system. The failure warning system is described in more detail below. The central opening 311C in the contact 311 allows condensate to pass through the bimetallic disk 357 when it is in its closed position and exit the drain 310 through the outlet opening 324 in the flow regulator 326. The central opening 3HC in the contact 311 is smaller than the outlet opening 324 in the flow regulator 326 and therefore is adapted to handle a smaller volume of condensate .

[00106] The float 342 can move with respect to the bimetallic disk 357 between a closed position of the float (Figs. 9A and 9B) and an opened position of the float (Fig. 9C) . The float 342 and its operation have been described in detail above and therefore will not be described again here. However, the primary difference in operation of the float 342 and the previously described configurations is that an engagement portion 344 of the float engages the upper surface 3HA of the contact 311 instead of the flow regulator.

[00107] Still referring to Figs. 9A-10, the drain 310, as mentioned above, includes a failure warning system for ^" iridi ^' caf ^" ihg ^"" to ^" the user ^" that the drain has failed. The failure warning system includes a passageway 371 through

the flow regulator 326. The passage 371 is in fluid communication with an annular channel 373 that is formed in a ledge 338 in the base 312 (Fig. 9A) . A lateral passage 375, as shown in Fig. 10, connects the annular channel 373 to a port 377 on the exterior of the base 312. Because of the bimetallic disk 357, failure of the drain 310 will cause the bimetallic disk to be in the open position and thereby prevent blockage of the outlet opening 328 and the failure warning system. Because the drain 310 fails open, steam will flow through the passage 371 in the flow regulator 326, through the annular channel 373 and the lateral passage 375 and out the port 377 on the exterior of the base 312. As a result, when the drain 310 fails a user will be able to observe steam outside of the drain. Most commonly, this embodiment would be used in a steam system located outside, such as is common at petrochemical facilities .

[00108] Figs. HA and HB show a drain 410 having yet another configuration. The drain 410 is substantially similar to the drain 210 of Figs 8A-8C. Parts of the drain 410 corresponding to parts of the drain 210 have been given the same reference numeral, plus "200". In this configuration, however, a guide pin 490 extends upward from a flow regulator 426 and is configured to be received in a central passage 446 in a float 442 for orienting the float, and preventing the float from canting. Locating the guide pin 490 at the bottom of float 442 through an engagement portion 444 better controls the alignment of the engagement portion with the longitudinal axis LA of the drain 410 and ensures flush engagement of the engagement portion with a seat 428. The guide pin 490 in the illustrated configuration has a generally circular cross-section but it is understood that the guide pin could have other cross- section (e.g., star, square, hexagonal). The guide pin 490 is shown generally aligned with a longitudinal axis of the drain but can have other locations .

[00109] Moreover, the flow regulator 426 includes an outlet opening 424 that is not centrally located in the flow regulator. As a result, the outlet opening 424 is spaced from the guide pin 490 and thus, the longitudinal axis LA of the drain. Accordingly, the outlet opening 424 is offset with respect to the engagement portion 444 of the float 442, which is aligned with the guide pin 490. It has been determined that offsetting the opening 424 with respect to the engagement portion 444 makes the float 442 easier to lift off of the seat 428. Accordingly, a larger outlet opening 424 can be used to drain off condensate more rapidly. The buoyant force of the float 442 acts along the central axis of the float that is spaced from the outlet opening 424. The right edge of the engagement portion 444 (as illustrated in the drawings) acts as a fulcrum. The buoyancy force thus has a lever arm by which to augment itself in lifting the float 442 off of the seat 428 against the vacuum force being applied through the eccentric outlet opening 424.

[00110] A small lateral orifice 450 extends through the engagement portion 444 of the float 442 and the flow regulator 426 so that condensate can exit an interior space 415 of the drain 410 without movement of the float 442. The lateral orifice 450 arrangement works well on piping systems that produce condensate on a constant basis. The relatively constant flow of condensate can exit through the lateral orifice 450 without movement of the float. As a result, the lateral orifice 450 results in less movement and thereby less wear on the float and the seat. The lateral orifice 450 can have various sizes to accommodate various condensate loads .

[00111] Figs. 12A-12C show a drain 510 of a second embodiment that is similar to the drain 310 of Figs 9A-10. Parts of the drain 510 corresponding to parts of the drain 310 have ^" been given the same reference numeral, plus "200". However, in this configuration a steam restrictor,

generally indicated 505, is connected to a contact portion 511 of a bimetallic disk 557. The steam restrictor 505 includes the body, generally indicated 517, having a cap 517A that defines a cavity 517B in the body and a lower cylindrical portion 519. In the embodiment of Figs. 12A and 12B, the cylindrical portion 519 of the body 517 is affixed to the contact portion 511 of the bimetallic disk 557. An inlet passage 522 of the steam restricter 505 includes a plurality of first (radial) passage members 522A (two are shown) and central axial bore opening 522B from the first passage members at one end and the cavity 517B at the other end. A thermodynamic stop disk 527 rests on the top surface of the cylindrical portion 519 and covers the central axial bore 522B of the inlet passage 522. When the disk 527 is in its closed position, flow through the steam restricter 505 is prevented. A plurality of outlet passages 529 (two being shown) extend through the cylindrical portion 519 so that fluid may flow from the cavity 517B through the drain outlet passages 529 and through the opening 511C in contact portion 511 of the bimetallic disk 557.

[00112] In operation, the steam restricter 505 of Figs. 12A-12C receives condensate flow into the radial passage members 522A of the inlet passage 522. Condensate flows from the radial passage members 522A into the central axial bore opening 522B of the inlet passage 522. As sufficient condensate enters the axial bore opening 522B, condensate causes the thermodynamic stop disk 527 to raise from its closed position (Figs. 12A and 12B) to its open position (Fig. 12C) . In the open position of the stop disk 527, condensate in the cavity 517B flows through the outlet passages 529 that extend axially through the cylindrical portion 519. Thus, condensate exits the steam restricter 505, passes through the opening 511C in the contact portion 511 of the bimetallic disk 557, and out an outlet opening 524 in a flow regulator 526. It is understood that a bleed

passage could be used to provide constant fluid communication between the radial passage members 522A and the outlet opening 524.

[00113] Figs. 13A and 13B show a drain 610 of a third embodiment that is substantially similar to the drain 510 of Figs 12A-12C except, in this configuration, the steam restrictor is a fixed orifice, labyrinthine trapping module, generally indicated at 629. Parts of the drain 610 corresponding to parts of the drain 510 have been given the same reference numeral, plus "100". The module 629 includes a cylindrical housing 631 having an open end and a closed end. A cover 633 attaches to the housing 631 for closing the open end. The closed end of the housing 631 includes an engagement portion 611 that defines an annular channel receiving an inner peripheral edge margin of a bimetallic disk 657. The housing 631 has an opening 635 and an interior annular groove 637 in fluid communication with the opening. The opening 635 and annular groove 637 allow condensate in an interior space 615 of the drain 610 to flow into the housing 631.

[00114] A cylindrical plug 639 is removablely received in the housing 631. The plug 639 has a series of internal passages 641 in fluid communication with the groove 637 in the interior of the housing 631. The plug 639 is shown removed from the housing 631 in Figure 14. The internal passages 641 are configured so that condensate can pass through the plug 639 as shown by arrows. Other internal passages 641 arrangements could also be used. The internal passages have a length and number of right angle turns sufficient so that any steam entering the passages will condense into condensate before reaching a passage outlet 643. Stated another way, the passages 641 have a labyrinthine configuration. The passage outlet 643 comprises a cavity that is positioned off-center within the plug 639. Condensate exits the passage outlet 643 through an opening 611C in the contact portion 611 of the

bimetallic disk 657 and into the outlet opening 624 in the flow regulator 626.

[00115] Figs. 15A and 15B show a drain 710 of a fourth embodiment that is substantially similar to the drain 610 of Figs 13A-13B except, in this configuration, the steam restrictor is a fixed orifice, nozzle trapping module, generally indicated at 729. Parts of the drain 710 corresponding to parts of the drain 610 have been given the same reference numeral, plus "100". The module includes a cylindrical housing 731 that is substantially the same as the housing 631 described above with respect to FIGS. 13A- 14. A cylindrical plug 739 of the nozzle trapping module 729 has a lateral passage 741A that is in fluid communication with a groove 736 in the housing 731. The lateral passage 741A intersects an axial passage 741B having a larger diameter than the lateral passage. The lateral and axial passages 741A, 741B in the plug 639 are designed such that any steam entering the passage will expand and condense into condensate before reaching a passage outlet 743. Condensate can flow through the passages 741A, 741B and out the passage outlet 743, which feeds into an opening 711C in the contact portion 711 of the bimetallic disk 757 and into an outlet opening 724 in the flow regulator 726.

[00116] Figs. 16A and 16B show a drain 810 of a fifth embodiment that is substantially similar to the drain 610 of Figs 13A-13B except, in this configuration, the bimetallic disk 657 has been replaced with a thermostatic bellows element generally indicated at 857. Parts of the drain 810 corresponding to parts of the drain 610 have been given the same reference numeral, plus "200". The bellows element includes a cylindrical wall 847 having a plurality of passages 847A (two passages being shown) . Adjacent the bottom of the cylindrical wall 847 are internal threads for connecting the bellows element 857 to a seat 828 of a flow regulator 826. A circular flange 849 having a central

opening extends radially inward from the top of the cylindrical wall 847. Extending downward from the flange 849 and spaced from the cylindrical wall 849 is a temperature responsive bellows member 853 that is capable of moving between an extended position (Fig. 16A) and a retracted position (Fig. 16B) in response to temperature changes within an interior space 815 of the drain 810. The bellows member 853 is tubular in shape and preferably liquid and gas impermeable. Affixed to an end of the bellows member 853 opposite the flange 849 is a washer 855.

[00117] The bellows member 853, in the normal operating condition, is expanded because of the heat in the interior space 815 thereby causing the washer 855 to engage a seat 828 of a flow regulator 826 to block a passage 871 through the seat. The passage 871 communicates with an annular channel 873 in the base 812. A failure warning passage 875 and an outlet passage 879 are connected to the channel 873.

The warning failure system in this configuration is substantially the same as that previously described. Cooling of the bellows member 853, such as during system shut down or drain 810 failure, causes the bellows member 853 to contract thereby raising the washer 855 and fluidly connecting the passage 871 with the interior space 815 of the drain 810. At the same time, contraction of the bellows member 853 fluidly connects the interior space 815 of the drain 810 with channel 873 and outlet passage 879, which connects with the exit passage 818. As a result, substantial amounts of condensate can exit the interior space 815 of the drain 810 even if the drain otherwise fails. The channel 873 and outlet passage 879 are sized to pass liquid at a greater rate than can be achieved through the steam restricter 829. It will be understood that there can be more than one outlet passage.

[00118] A labyrinthine trapping module, generally indicated at 829, is substantially similar to the labyrinthine trapping module 629 of Figs 13A-13B. However,

the module 829 includes a tubular portion 863 extending downward from a closed end of a cylindrical housing 831. The tubular portion 863 includes a passageway 863A connecting a passage outlet 843 to an outlet opening 824 in the flow regulator 826. A spring 865 biases the labyrinthine trapping module 829 against the flow regulator 826 to inhibit movement of the labyrinthine trapping module. In other words, the spring 865 holds the labyrinthine trapping module 829 in place. Because of the compressibility of the spring 865, the spring allows the labyrinthine trapping module 829 to be used in different size drains. Moreover, the spring 865 can be replaced with a spring of a different size to allow even more flexibility in the sizes of drains in which the labyrinthine trapping module 829 can be used.

[00119] Figs. 17A and 17B show a drain 910 that is substantially similar to the drain 810 of Figs 16A-16B except, in this configuration, the labyrinthine trapping module 829 has been replaced with a fixed orifice nozzle trapping module generally indicated at 929. Parts of the drain 910 corresponding to parts of the drain 810 have been given the same reference numeral, plus "100". The nozzle trapping module 929 is substantially the same as the nozzle trapping module 729 described above with respect to Figs. 15A and 15B.

[00120] Figs. 18A-18C show a drain 1010 that is substantially similar to the drain 810 of Figs 16A-16B except, in this configuration, the labyrinthine trapping module 829 has been replaced with a steam restrictor generally indicated at 1005. Parts of the drain 1010 corresponding to parts of the drain 810 have been given the same reference numeral, plus "200". The steam restrictor is substantially the same as the steam restrictor 505 described above with respect to Figs. 12A-12C.

[00121] Figs. 18D-18E show a drain 1010' that is substantially similar to the drain 1010 of Figs 18A-18C

except, in this configuration, a labyrinthine trapping module 1029' is affixed to a washer 1055' of a temperature response bellows member 1053 ' and the spring 1065 has been removed. As a result, the labyrinthine trapping module 1029' moves upward as the temperature responsive bellows member 1053 ' moves from an extended or closed position (Fig. 18D) to a retracted or open position (Fig. 18E) in response to temperature changes within an interior space 1015' of the drain 1010'. With the bellows member 1053' in its retracted position, condensate can flow through the two passages 1047A' in a cylindrical wall 1047' of the bellows member and exit the interior space 1015' of the drain 1010' through an outlet opening 1024 ' .

[00122] Figs. 19A-19C show a drain 1110 that is substantially similar to the drain 810 of Figs 16A-16B except, in this configuration, the labyrinthine trapping module 829 has been replaces with a float 1142. Parts of the drain 1110 corresponding to parts of the drain 810 have been given the same reference numeral, plus "300". The float is substantially the same as the float 242 described above with respect to Figs. 8A-8C but without a guide pin 290.

[00123] Figs. 19D-19E show a drain 1110' that is substantially similar to the drain 1110 of Figs 19A-19C except, in this configuration, a cylindrical engagement portion 1155A' extends upward from a washer 1155' of a temperature responsive bellows member 1053 ' to define a seat 1155B' for engagement with a float 1142'. The cylindrical engagement portion 1155A' moves upward as the temperature responsive bellows member 1053 ' moves from an extended position (Fig. 19D) to a retracted position (Fig. 19E) in response to temperature changes within an interior space 1115 ' of the drain 1110 ' . The engagement portion 1155A' includes an axial opening 1155C for allowing condensate to flow through the engagement portion even when the float 1142' is closed. The float 1142' can move

independently of the bellows member 1153'. Thus, three different flow openings for escape of condensate are provided.

[00124] As can be appreciated, a condensate removal drain can be configured using any of the modular components described above to best suit a specific steam system. Thus, combinations of components other than those illustrated in the drawings can be used within the scope of the present invention. In addition, an operator of a steam system may choose to alter a drain of the present invention after it has already been installed in a steam system by using one or more of the modular components to better suit the drain for the flow conditions of the steam system. For instance, when flow conditions change or if the conditions were incorrectly estimated, the operator may quickly change one or more of the drain components to better suit the drain for the condensate load produced by the steam system. Thus, the present invention reduces maintenance time. It also permits a reduction in inventory, since there is no need to maintain a variety of complete condensate removal devices in stock but only to maintain a variety drain components .

[00125] When maintenance is required, as to clean the trap or remove a clog, the cap may be easily removed from the base and the device repaired as needed while the base stays threaded in-line. The mesh screen may be cleaned by directing fluid toward the screen to dissolve accumulated deposits. Maintenance time is reduced because there is no need to break the pipe line to service the device.

[00126] Referring now to Figs. 20 and 22, a steam restricter, indicated generally at 1201, is constructed so as to be easily retrofitted into an existing steam trap, generally indicated 1203, of a forced air steam heater 1207 (Figs. 20 and 21) . In the illustrated embodiment, the ^" heater 1207 includes a housing 1209 enclosing a fan 1211 and a steam coil 1213 that receives steam from steam piping

(not shown) . As shown in Fig. 21, the fan 1211 operates to draw in outside air, indicated by arrows Al, and return air, indicated by arrows A2 , from the room Rl being heated and discharges air, indicated by arrows A3, that has been heated by the steam coil 1213. During the heat exchange process, condensate (not shown) collects in the steam trap 1203 connected to the steam coil 1213 and is removed from the steam piping by flow through a condensate return line 1215. Removal of the condensate from the steam piping is needed to maintain performance of the heater 1207. The steam restricter 1201 of the present invention is installed in the steam trap 1203 to control the removal of condensate from the trap and prevent the loss of steam from the steam piping supplying steam to the steam coil 1213. It is understood that the steam restricter 1201 may be installed on a conventional convection steam radiator heating system, or on systems using steam for purposes other than heating without departing from the scope of this invention. Furthermore, the steam restricter 1201 may be installed as a retrofit for an existing steam trap 1203 or may be incorporated as a component of a steam trap assembly supplied for installation with a new heater 1207.

[00127] As shown in Fig. 22 the steam trap 1203 includes a collecting bowl, generally indicated 1221, defining a chamber 1223 for receiving condensate and containing the steam restricter 1201. The bowl 1221 has an inlet 1227 connected to the heater 1207 (Fig. 20) for admitting steam and condensate into the chamber 1223 and a drain 1229 having an outlet passage 1231 at the bottom of the bowl for the passage of condensate from the chamber to the condensate return 1215 (Fig. 20) . Condensate is returned to the boiler (not shown) that supplies steam to the steam coil 1213 in the heater 1207 via the condensate return 1215. A removable cover 1233 defines the upper wall of the ^" steam trap 1203 and is threadably attached to the

collecting bowl 1221 to enclose the chamber 1223 and allow access to the chamber by removing the cover.

[00128] As shown in Figs. 22 and 23, the steam restricter 1201 has a central longitudinal axis Ll and includes a body, generally indicated 1241, received in an annular filter 1243 in the chamber 1223 (Fig. 22) . The annular filter 1243 is made of corrosion resistant wire mesh so as to prevent the ingress of debris (e.g., rust, small pipe fragments, etc.) into the body 1241. A mating base, generally indicated 1247, at the bottom surface of the body 1241 is sized and shaped for connection to the drain 1229 of the steam trap 1203 (Fig. 22) to force fluid in the steam trap to flow through the restricter 1201. A gasket 1251 between the mating base 1247 and the drain 1229 prevents the flow of fluid between the restricter 1201 and the drain of the steam trap 1203. A coil spring 1253 housed in the chamber 1223 applies a downward force acting on the steam restricter 1201 that presses the mating base 1247 against the gasket 1251 surrounding the drain 1229 of the steam trap 1203 to prevent the passage of fluid between the restricter and the drain. A filter (not shown) may be more elongated along its axis of rotation so that it can extend up to the cover 1233 and surround the spring 1253. Filters of different sizes and shapes may be used, or the filter may be omitted within the scope of the present invention.

[00129] As shown in Figs. 23-25, the body 1241 includes a cylindrical portion, generally indicated 1257, having a top surface 1259, a bottom surface 1261, and a side surface 1263. As shown in Fig. 24 and 25, the bottom surface 1261 has an outer annular recess 1267 sized for receiving the mating base 1247 and a central recess 1269 that forms a manifold 1271 at the bottom of the cylindrical portion 1257. The body 1241 includes a cap, generally indicated ^" 1275/ ^" separate ^" from ^" the cylindrical portion 1257 and releasably connected to top surface 1259. The cap 1275 has

a top wall 1277 and a cylindrical side wall 1279 extending downward from the top wall. The cylindrical side wall 1279 of the cap 1275 has an inner surface 1281 and an outer surface 1283. The cap 1275 is shaped to receive a top portion of the cylindrical portion 1257 of the body 1241 and define a cavity, generally indicated 1289, between the top surface 1259 of the cylindrical portion and the top wall 1277 of the cap. In the illustrated embodiment, the top wall 1277 of the cap 1275 has a cylindrical protrusion 1291 that is received by the coil spring 1253 (Fig. 23) housed in the chamber 1223 (Fig. 22) of the steam trap 1203. As shown in Fig. 22, the coil spring 1253 acts against the cover 1233 of the steam trap 1203 and biases the cap 1275 downward forcing the body 1241 into sealing engagement with the mating base 1247. It is understood that the cap 1275 may have a generally flat top wall 1277 without the protrusion 1291 so that the overall height of the steam restricter 1201 is reduced.

[00130] The body 1241 has an inlet passage, generally indicated 1295, in the cylindrical portion 1257 opening from the chamber 1223 of the steam trap 1203 to allow fluid to enter the body. In the illustrated embodiment, the inlet passage 1295 comprises three first inlet passage members 1299 (two of which are shown in Figs. 22-25) opening from the side surface 1263 of the cylindrical portion 1257 to receive fluid from the chamber 1223 of the steam trap 1203. As shown in Fig. 26, the inlet passage members 1299 are generally cylindric passages extending generally radially of the body 1241. The inlet passage members 1299 are spaced apart an approximately equal angular distance (e.g., 120 degrees) around the circumference of the body 1241. The number of inlet passage members 1299 may be other than three without departing from the scope of the present invention.

[00131] The inlet passage 1295 includes a second inlet passage member, generally indicated 2103, in the

cylindrical portion 1257 of the body 1241 in fluid communication with the three first inlet passage members 1299. In the illustrated embodiment, the second inlet passage member 2103 is an axial bore in the cylindrical portion 1257 of the body 1241 that is coaxial with the central longitudinal axis Ll of the steam restricter 1201.

As shown in Fig. 24 and 25, the second inlet passage member 2103 has a top portion (mouth) 2105 that opens at the top surface 1259 of the cylindrical portion 1257 for fluid communication with the cavity 1289. The second inlet passage member 2103 has a conical bottom wall 2107 spaced above the bottom surface 1261 of the cylindrical portion 1257.

[00132] Referring to Figs. 23-25, the top of the cylindrical portion 1257 of the body 1241 has an inner annular wall 2111 that defines the top portion 2105 of the second inlet passage member 2103 and an outer annular wall 2115 radially spaced from the inner annular wall. The outer annular wall 2115 has an upper side surface 2119 inwardly offset from a lower side surface 2121. The cylindrical portion 1257 has an outer annular shoulder 2125 adjacent the lower side surface 2121 of the outer annular wall 2115 and the side surface 1263 of the cylindrical portion 1257. The cylindrical side wall 1279 of the cap 1275 is shaped to receive the outer annular wall 2115 of the cylindrical portion 1257 to enclose the cavity 1289 of the steam restricter 1201. The lower side surface 2121 of the outer annular wall 2115 and the inner surface 1281 of the cylindrical side wall 1279 of the cap 1275 may have mating threads (not shown) so that the cap may be threadably connected to the cylindrical portion 1257 of the body 1241. The top surface 1259 of the cylindrical portion 1257 has an annular channel 2129 between the inner annular wall 2111 and the outer annular wall 2115 that defines a ^" lower portion ^" of ^" the ^" cavity 1289.

[00133] A drain outlet passage, generally indicated 2135, is in fluid communication with the cavity 1289 for passing condensate from the cavity to the drain 1229 of the steam trap 1203. The drain outlet passage 2135 includes three cavity passage members 2137 (two of which are shown in Figs. 23-25), the manifold 1271 at the bottom of the cylindrical portion 1257 of the body 1241, and a drain passage member 2139 in the mating base 1247. As shown in Figs. 23 and 28, the three cavity passage members 2137 each open from the annular channel 2129 of the cylindrical portion 1257 and extend generally vertically though the cylindrical portion of the body 1241 to the manifold 1271 at the bottom of the cylindrical portion. The cavity passage members 2137 allow fluid communication between the lower portion 2129 of the cavity 1289 and the manifold 1271 at the bottom of the body 1241. As shown in Fig. 26, the cavity passage members 2137 are angularly spaced between the first inlet passage members 1299 that pass radially through the body 1241. In one embodiment, the combined cross-sectional area of the three cavity passage members 2137 is equivalent to the cross-sectional area of the second inlet passage member 2103 so that fluid flow from the second inlet passage member to the manifold 271 is not restricted.

[00134] The manifold 1271 of the outlet passage 2135 at the bottom of the cylindrical portion 1257 is in fluid communication with the drain passage member 2139 in the mating base 1247 so that fluid can pass from the manifold to the drain 1229 of the steam trap 1203. In the illustrated embodiment, the drain passage member 2139 extends parallel to the central axis Ll of the body 1241 through the mating base 1247 to a port 2141 that opens into the drain 1229 of the steam trap 1203 to allow condensate to exit the steam restricter 1201 and flow into the condensate return 1215. The port 2141 of the drain passage member 2139 is in registration with the cavity 1289 to

allow condensate to flow from the cavity into the drain 1229 via the drain outlet passage 2135.

[00135] As shown in Fig. 25, the mating base 1247 is generally tubular with a tubular lower portion 2155 that defines the drain passage member 2139 and has an outer diameter D. The mating base 1247 has a flange 2157 for connection to the cylindrical portion 1257 of the body 1241. The flange 2157 is sized for being received in the outer annular recess 1267 and has an upper surface 2159 in contact with the outer annular recess of the cylindrical portion 1257 of the body 1241 and a lower surface 2161 in contact with the gasket 1251 (Fig. 22) on the drain 1229 of the steam trap 1203. The sealing contact between the upper surface 2159 of the flange 2157 and the body 1241 of the restricter forces steam in the manifold 1271 to pass through the drain passage member 2139 in the mating base 1247.

[00136] As shown in Fig. 22, the lower portion 2155 of the mating base 1247 is sized and shaped for reception into the drain 1229 of the steam trap 1203. In the illustrated embodiment, the mating base 1247 is removably attached to the cylindrical portion 1257 of the body 1241 so that the base may be readily replaced with a base sized to fit a specific size drain opening. For example, the mating base 1247 may be replaced with a mating base having a lower portion with a smaller diameter D so that the base is sized to correspond with a steam trap 1203 having a smaller drain (not shown) . Alternatively, the mating base 1247 may be replaced with a mating base sized to fit a larger drain (not shown) .

[00137] A thermodynamic stop disk 2175 is disposed in the cavity 1289 and is supported by the top surface 1259 of the cylindrical portion 1257. As shown in Figs. 24 and 25, the disk 2175 has a top surface facing the top wall 1277 of ^" the ^" cap ^" r27 ^" 5 ^~ arid ^" a ^" bottom surface in contact with the top surface 1259 of the cylindrical portion 1257 at a closed

position of the disk (Fig. 24) . The thermodynamic stop disk 2175 is positioned for movement in the cavity 1289 relative to the body 1241 between an open position (shown in phantom in Fig 24) in which the stop disk permits fluid communication through the body from the second inlet passage member 2103 to the drain outlet passage 2135 and the closed position in which the stop disk blocks fluid communication from the second inlet passage to the drain outlet passage. In the closed position, the bottom surface of the stop disk 2175 is seated against the top surface of the inner annular wall 2111 of the cylindrical portion 1257 of the body 1241 to prevent the flow of fluid from the second inlet passage member 2103 into the cavity 1289. Also, the bottom surface of the thermodynamic stop disk 2175 is seated against the top surface of the outer annular wall 2115 of the cylindrical portion 1257 to seal against the flow of fluid from the cavity 1289 into the three cavity passage members 2137. In the open position, the disk 2175 is out of contact with the top surface 1259 of the cylindrical portion 1257 of the body 1241 so that fluid can flow from the second inlet passage member 2103 into the annular channel 2129 of the cavity 1289 and into the cavity passage members 2137 opening to the manifold 1271 at the bottom of the cylindrical body.

[00138] In one particular embodiment, the cylindrical portion 1257 of the body 1241 includes a condensate passage 2181 comprising a fixed diameter orifice in the conical bottom wall 2107 of the second inlet passage member 2103. The condensate passage 2181 is coaxial with second inlet passage member 2103 and passes through the cylindrical portion 1257 of the body 1241 to the manifold 1271. In the illustrated embodiment, the condensate passage 2181 has a fixed diameter across the length of the passage. The diameter of the condensate passage 2181 in the body 1241 is selected based ^" on the condensate load requirements of the specific application and should be sized to adequately

drain an estimated ordinary quantity of condensate load. The condensate passage 2181 is located in the conical bottom wall 2107 at the low point of the inlet passage 1295 in the steam restricter 1201 whereby liquid that collects in the inlet passage will flow through the condensate passage to the drain outlet passage 2135. Further, the position of the condensate passage 2181 minimizes the occurrence of steam entering the passage because in normal operation liquid will collect on the conical bottom wall 2107 of the second inlet passage member 2103 and seal against the flow of steam through the condensate passage. In the event that steam enters the condensate passage 2181, the steam will enter the manifold 1271 which has a larger diameter than the condensate passageway. Once steam enters the manifold 1271 from the condensate passage 2181 it will expand and be more likely to condense into water prior to being released out the drain outlet passage 2135.

[00139] The condensate passage 2181 is sized for an expected constant load of condensate that enters the steam restricter 1201. When the actual load is larger than the estimated load for which the condensate passage 2181 is sized, condensate collects in the second inlet passage member 2103 and begins to rise until the thermodynamic stop disk 2175 is lifted. It is understood that the condensate passage 2181 may be omitted from the steam restricter 1201 of the present invention so that all liquid condensate passes through the second inlet passage member 2103 and the three cavity passage members 2137 of the drain outlet passage 2135.

[00140] In use, the steam restricter 1201 of the present invention allows condensate that collects in the steam trap 1203 to drain to the outlet 1229 of the trap and prevents steam from leaking from the steam system of the heater 1207 through the steam restricter. As condensate ^" collects in the steam trap 1203, liquid will enter the first inlet passage members 1299 and pass through the

cylindrical portion 1257 of the body 1241 into the second inlet passage member 2103. As liquid condensate fills the second inlet passage member 2103 a small amount of liquid will pass through the condensate passage 2181 in the conical bottom wall 2107 of the second inlet passage. If a larger volume of liquid is received in the inlet passage 1295 of the restricter, liquid will fill the second inlet passage member 2103 and the thermodynamic forces in the body 1241 cause the thermodynamic disk 2175 to lift. When the thermodynamic disk 2175 lifts, liquid will exit the second inlet passage member 2103 and pass through the annular channel 2129 forming the lower portion of the cavity 1289 and into the cavity passage members 2137. The condensate will flow through the cavity passage members 2137 into the manifold 1271 at the bottom of the cylindrical portion 1257 of the body 1241 and into the drain passage member 2139 of the mating base 1247. The mating base 1247 is positioned in the drain 1229 of the steam trap 1203 so the condensate discharged from the steam restricter 1201 enters the drain and the condensate return 1215 attached thereto. In this way, condensate is allowed to exit the steam trap 1203 through the steam restricter 1201 while steam is prevented from passing through the restricter to the drain outlet 2135. When the condensate has been drained through the drain outlet passage 2135 of the restricter 1201, steam will enter the cavity 1289 which forces the thermodynamic disk 2175 to close. It is understood that the disk 2175 will cycle (raise and lower) based on the volume of condensate load received in the steam restricter 1201.

[00141] The steam restricter 1201 of the present invention is capable of operating efficiently over a wide range of load variations. A small constant load of condensate flows through the condensate passage 2181 while larger fluctuations ^" in condensate load pass through the inlet passage 1295, cavity 1289, and drain outlet passage

2135 of the restricter 1201. The modular design and interchangeability of the parts of the steam restricter 1201 of the present invention allows the restricter to be modified to fit specific operating parameters. For example, the body 1241 can be changed to increase or decrease the size of the condensate passage 2181 if the constant condensate load of a specific application differs from what was expected for the application. Also, the mating base 1247 can be changed to vary the diameter D of the lower portion 2155 of the base to accommodate a variety of drain sizes. Further, the restricter 1201 of the present invention with the first inlet passage members 1299 being radial openings in the body 1241 and the second inlet passage member 2103 and three cavity passage members 2137 being vertical openings, is compact so that the body has an overall size that may fit in a variety of existing steam traps 1203.

[00142] The advantageous construction of the steam restricter 1201 is illustrated by the method in which the device may be retrofitted to an existing steam trap 1203. Prior to beginning the retrofitting operation, the particular steam system would be analyzed to determine the appropriate body 1241 and mating base 1247 for the particular operational characteristics (e.g., the expected condensate flow rates) of the steam system. The steam restricter 1201 of the present invention requires less analysis of the existing steam system prior to the retrofitting operation because the steam restricter is capable of handling a range of condensate flow rates. To begin retrofitting the steam restricter 1201, the cover 1233 is unscrewed from the steam trap 1203 and removed to expose the chamber 1223. The existing steam restricter (not shown) is removed from the chamber 1223. The steam restricter 1201 is inserted into the chamber 1223 with the ^~ lower portion 2155 of the mating base 1247 sliding into the drain 1229. Insertion of the lower portion 2155 into the

drain 1229 blocks communication from the chamber 1223 to the condensate return 1215 except through the steam restricter 1201. The gasket 1251 is positioned between the bottom surface 2161 of the flange 2157 of the mating base 2155 and the drain 1229 to seal the mating base in the drain. To secure the steam restricter 1201 in the drain, a coil spring 1253 of the type described above is selected from a plurality of coil springs having different relaxed lengths. The selected spring 1253 will have a relaxed length greater than the vertical height between the top wall 1277 of the cap 1275 and the cover 1233 of the steam trap 1203. The lower end of the spring 1253 is fitted on the cylindrical protrusion 1291 of the cap 1275 and the cover 1233 is screwed back onto the bowl 1221 of the steam trap 1203. The spring 1253 is then held in compression between the cover 1233 and the cap 1275 of the body 1241 such that it exerts a force on the body of the steam restricter 1201 that presses the outlet base 1247 into sealing engagement with the gasket 1251 mounted on the drain 1229.

[00143] Maintenance of the steam restricter 2101 consists of occasional cleaning of the annular filter 1243 and condensate passage 2181. The steam restricter 1201 may be separated from the bowl 1221 of the steam trap 1203 by removing the cover 1233 and lifting the steam restricter out of the chamber 1223. After removing the gasket 1251 and the mating base 1247 from the body 1241, the filter 1243 may be slid off the body and blown clean. The condensate passage 2181 as well as the first inlet passage members 1299, second inlet passage member 2103, and cavity passage members 2137 of the cylindrical portion 1257 of the body 1241 may also be blown clean. The steam restricter 1201 is reassembled and replaced in the chamber 1223 by following the same steps described above for the initial -retrofit of the restricter into the steam trap 1203.

Removal and replacement of the steam restricter 1201 may be carried out without the use of any tools .

[00144] A steam restricter kit, generally indicated 2189, for retrofitting a steam restricter is shown in Fig. 30 and includes the component parts of the steam restricter 1201 shown in Fig. 23. In addition, the kit 2189 includes a plurality of mating bases 2191, 2193 (two are shown) each having the same general configuration as the mating base 1247 (Fig. 23), but having respective tubular portions 2195, 2197 with different outer diameters Dl, D2. The kit 2189 also includes a plurality of annular gaskets 2199, 2201 (two are shown) having internal diameters corresponding to the different outer diameters Dl, D2 of the mating bases 2191, 2193. Using the kit 2189 of the present invention, the retrofit of the steam restricter 1201 to steam traps 1203 which include drains 1229 having outlets 1231 of different sizes may be accomplished by selecting the mating base 2191, 2193 (and its corresponding gasket 2195, 2197) having the outer diameter Dl or D2 corresponding to the particular drain into which the lower portion 2195, 2197 of the mating base is inserted. Moreover, the kit 2189 may include a plurality of coil springs 2205, 2207 (two are shown) having different relaxed lengths. The coil spring 2205, 2207 of the appropriate length may then be selected depending upon the vertical space between the cover 1233 of the steam trap 1203 and the top wall 1277 of the cap 1275.

E00145] Fig. 31 illustrates another embodiment of the steam restricter, generally indicated 2251. As with the previous embodiment, the body, generally indicated 2255, of the steam restricter 2251 includes a cap 2257 that defines a cavity 2259 in the body and a lower cylindrical portion 2263. In the embodiment of Fig. 31, the cylindrical portion 2263 of the body 2255 is formed integral with the mating base 2267 of the steam restricter 2251 that is received in the drain 1229 (Fig. 22) of the steam trap

1203. The inlet passage 2271 of the steam restricter 2251 includes a plurality of first (radial) passage members 2275 (two are shown) above the mating base 2267 and second (axial) passage members 2281 each opening from a respective first passage member at one end and the cavity 2285 at the other end. As in the previous embodiment, a thermodynamic stop disk 2289 rests on the top surface of an inner annular wall 2291 and the top surface of an outer annular wall 2293 of the cylindrical portion 2263. At the closed position of the disk 2289, flow through the steam restricter 2251 is prevented. The inner annular wall 2291 and outer annular wall 2293 of the cylindrical portion 2263 are separated by an annular channel 2295 forming the lower portion of the cavity 2285. In the embodiment of Fig. 31, the drain outlet passage 2299 comprises a central axial bore 2301 of the cylindrical portion 2263 that passes from the top surface 2303 of the cylindrical portion to the bottom surface 2305 of the mating base 2267 so that fluid may flow from the cavity 2285 through the drain outlet passage 2299 and into the drain 1203 of the steam trap 1201.

[00146] In operation, the steam restricter 2251 of Fig. 31 receives condensate flow into the inlet passage members 2275 of the inlet passage 2271 as indicated by arrows A4. As condensate flows into the restricter 2251, fluid flows from the inlet passage members 2275 into the axial passage members 2281 of the inlet passage 2271. As sufficient fluid enters the axial passage members 2281, fluid fills the annular channel 2295 of the cavity 2285 and causes the thermodynamic stop disk 2289 to raise from its closed position to its open position shown in Fig. 31. In the open position of the stop disk 2289, fluid in the cavity 2285 flows through the central axial bore 2301 that passes from the cavity 2285 to the bottom of the mating base 2267 so that fluid exits the steam restricter 2251 and enters the drain 1203 of the ^' steam ^" trap ϊ201.

[00147] Fig. 32 illustrates another embodiment of the steam restricter, generally indicated 2251', which is substantially similar to the steam restricter 2251 of Fig. 31. Components of the steam restricter 2251' corresponding to the components of the steam restricter 2251 are indicated by the same reference numeral with a " ' " . A thermodynamic stop disk 2289' includes an annular groove 2289A ¹ (broadly, "a recess") that is located adjacent two, spaced inlet axial passage members 2281'. As illustrated in the drawings, adjacent the annular groove is a chamfered edge 2289B ¹ . The chamfered edge is located an angle A5 with respect to a plane of the stop disk 2289' between 0 degrees and 90 degrees. For example, the angle A5 can be between about 15 degrees and 75 degrees. In the illustrated embodiment, for example, the angle A5 is 45 degrees. The chamfered edge 2289B' allows steam to pass stop disk 2289' and enter a cavity 2285'. Steam in the cavity 2285 ' provides backpressure against the thermodynamic stop disk 2289 thereby preventing the stop disk from moving from a closed position to an open position as a result of the steam.

[00148] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.

[00149] When introducing elements of the present invention or the preferred embodiments (s) thereof, the articles "a", "an", "the" and "said" are intended to mean that there are one or more of the elements . The terms "comprising", "including" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[00150] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

[00151] As various changes could be made in the above described drain without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense ,