BACKGROUND This disclosure relates generally to valves usable to deliver water from housing or building plumbing lines. More particularly, it concerns improvements to such valves, simplifying their construction, and enhancing their performance.

There is need in such valves for improvements associated with blocking, or checking, back-flow where reverse flow pressure may build up. Also, there is need in such valves for disposing of built-up back flow pressure, as during checking or blocking of such back flow to the building plumbing. Such back flow, if unchecked, could contaminate water in that plumbing.

Existing hydrants rely on a plunger to engage a seat, to limit flow, by spring force alone. If the spring force is too strong it restricts flow; and if the spring force is too weak, or if the plunger is corroded into the housing, it will not or may not properly shut off on the seat. If the plunger does not effectively shut off on the seat (to act as a check valve) , it will not prevent backflow, backsiphonage or relieve backpressure. Build-up of backpressure would or could disrupt use of a plastic hydrant outer tube or body. Also, existing hydrants might pass the ASSE 1019 requirements when new, but would likely fail the requirements after a short period of "infield use". After three years it was found in a survey that about 68% of such hydrants failed to pass the ASSE 1019 tests. There is need for improvements in hydrants as provided by the present disclosure, and wherein one or both of elongated outer and inner tubular body members consist of pressure expansible plastic material, in compact configuration, and are characterized by high reliability, absence of bore corrosion, and ease of installation and operation, and wherein an annular seal extends about an axis defined by a closure member, there being an axially elongated bore defined by the outer member, and into which the seal has sliding sealing fit as the inner member is advanced. There is particular need for improvements in hydrants that provide protection against freeze conditions.

SUMMARY

An improved, compact, simple, highly effective back flow preventing valving assembly, meeting the above need is provided. Basically the assembly includes

a) an outer tubular member having a first flow port, b) an inner member having closure means thereon to close said port in relatively axially advanced position of said closure means, and to open said port in relatively axially retracted position of said closure means,

c) control means to control relative movement of the inner and outer members,

d) a second port located sidewardly of said outer tubular member to pass fluid from space between said members to relieve fluid pressure build-up under freeze conditions. Added features of the preferred embodiment include provision of the closure means to comprise an annular seal extending about an axis defined by said closure member, there being an axially elongated bore defined by said outer member, and into which said seal has sliding sealing fit as the closure is advanced; a hollow valve body carrying said members; and an adjustment handle carried by said body to adjust the inner member between relatively advanced and retracted positions. As will be seen, the hollow valve body is typically metallic, and endwise supports the outer tubular member.

Another feature includes location of the outer member to extend endwise between the handle, typically metallic, and relatively slidable sealing elements, in such manner as to provide added benefits.

Yet another feature includes provision for redundant or multiple redundant relieving of excess pressures, as during freeze conditions .

Another feature is a wall hydrant which has the ability to drain at least some of the residual water when, under freezing conditions, residual water freezes because of a hose or the like being attached to the discharge nozzle.

A further feature is a relief valve for the captured residual water to escape back towards the supply of pressurized water when the frozen water in the exterior of the hydrant creates excessive pressure on the remainder of the residual water in the hydrant .

These and other features and advantages of an illustrative presently preferred embodiment, will be more fully understood from the following specification and drawings, in which:

DRAWING DESCRIPTION

Fig. 1 shows hydrant structure in flow "OFF" or blocking position;

Fig. 2 is like Fig. 1, but shows the structure in flow "ON" or unblocked position;

Fig. 3 is a section showing water pressure release through the bore of the inner tubular member;

Fig. 4 is like Fig. 3 but showing sealing position of a relatively slidable sealing element;

Fig. 5 is a fragmented section showing modified elements in advanced position of the slidable sealing element;

DETAILED DESCRIPTION

In Figs. 1 and 2, an outer tubular member 10, typically consists of metal or synthetic resinous or plastic material, and includes interfitting sub-members 10a and 10b. A first flow port 11 is provided and is typically cylindrical. An inner tubular member 12 is also provided to extend coaxially with 10, as respects longitudinal axis 12a. Member 12 also and typically may consist of metal or plastic material. An annular check member 35 permits fluid flow towards outlet tubing 20 and blocks fluid flow into port 11. Of added importance is the ability of check member 35 to seal during icy fluid conditions. Closure means 13, at the end of 12, serves to close port 11 in relatively axially advanced position of the closure means 13, as shown in Fig. 1; and to open port 11 in relatively axially retracted position of the means 13 as shown in Fig. 2. The closure means 13 typically includes an elastomeric ta ^¬ ring 13a fitting about stem 14a of a plug or "bullet" body 14, there being a body extension or stem 14b projecting rearwardly into the member 12 for carriage by the latter. Element 14 typically may consist of metal, and is carried to move forwardly under increased pressure exerted by forwardly expanding freezing hydraulic fluid in annular space 15 between 10 and 12, as in closed Fig. 1 position of the valve. At that time, O-ring 13a slidably seals against bore 16 of plastic tubular part 10b. Since that seal is a sliding seal, variation in such fluid pressure, normally about 60 psi, does not affect such closure.

When a control means, such as valve handle 18 is rotated in one direction, for example counter-clockwise, the sealing O-ring 13a backs away, i.e. leftwardly, from the bore 16, as in Fig. 2, allowing pressurized water to flow leftwardly from inlet tubing 21 past the element 14 and the O-ring, defining a flow port 100 to flow to the outlet tubing at 20 carried by body 19, as for delivery from a building or residence. A residence wall is indicated at 17, in Fig. 2, and engaged by body flange 19a. When handle 18 is rotated clockwise, inner member 12 moves rightwardly to advance closure means 13 to Fig. 1 "OFF" position.

Handle 18 has connection to a threaded metallic tube 22 that carries the leftward end of inner tubing 12. Tube 22 has threaded connection at 23 to a fitting 24, that in turn connects to the body 19. The rightward end of body part 19b carries the outer tubular metallic or extruded plastic member 10, as shown by coupling 25. An external stop shoulder 26 on fitting 24 limits rightward travel of the rotated handle, tube 22 and inner tubing 12, in Fig. 1 position; and an internal stop shoulder 27 on the fitting 24 limits leftward travel of 22 and 12 in response to opposite direction rotated travel of the handle and tubing 12, in Fig. 2. An abutment 30 on tube 22 engages shoulder 27. Note that tube 12 is rotated by the handle, to rotate seal 13a, as it advances or retreats in bore 11, to aid such seal formation.

As will be seen, a second fluid port, i.e. a side port, as for example at 101, in tube 22, is located sidewardly of the inner tubular member to pass escape fluid in relatively retracted position of the inner member to redundantly relieve fluid pressure in space 15 within 12, the inner member being elongated and extending lengthwise in said outer tubular member. Relief of pressure that might damage the hydrant, in the first instance is provided by rightward expansion or travel of plug or bullet 14 and seal 13a, in the bore of 11. Fluid in space 15 accesses space 15a via clearances between stem 14b and bullet 14, and between 14b and the bore 12b of member 12, when bullet 14 moves forwardly to disengage the end of 12.

Figs. 3 and 4 are similar to Figs. 1 and 2, but show pressurized fluid flow into the interior 60 of inner tubular member 12, via a gap 61 between the end 12a of member 12 and the stem 14b. Such fluid can escape to the exterior via axial passage 63 within member 12, and a radial outlet 101 in tube 22, proximate handle 18.

Fig. 5 shows a modification for further pressurized fluid flow 41 into inlet tubing 21 when O-ring 13a moves past shoulder 1 lb of bore 11.

Of importance, as an added feature of the invention, is the ability to mold the left end portion of plastic member 10 into position in metallic tubular connector 25, or equivalent metallic support structure, for example 19b, to simplify and reduce cost of fabrication .

In the above, both the inner and outer tubular members may consist of extruded plastic material, or of metal.

Figs. 1-4 also show provision of an elastomeric cup seal 35 carried by the element 14, and which spreads or diverges conically, rearwardly, in Fig. 4, so that is outer lip 35a engages the bore of outer plastic member 10 as O-ring 13a retracts into the bore 10b. The skirt of the seal is collapsed against bore 10b as seal 13a protrudes beyond 10b.