SEPTIC DRAIN LINE FLOW CONTROL SYSTEM

Field of the Invention

The present invention relates to drainage systems and, in particular, to a system for controlling the flow of effluent in septic drain lines.

Background of the Invention

Septic systems for handling the effluent from structures terminate in buried fields of drain pipes for leaching the effluent into the ground. Notwithstanding careful installation, the elevations and pitches of the drain pipes vary, resulting in a lesser number of drain pipes preferentially handling the output. Under adverse conditions, the ground surrounding the active pipes can become saturated resulting in the effluent penetrating and contaminating the ground surface. Such conditions do not affect the operation of the septic system and may not be apparent to the structure users in order to undertake the necessary maintenance or repair. If normal drainage cannot be restored, a separate secondary system may be required. Also, during the course of structure occupancy, the

effectiveness of the original septic system may be compromised for other reasons, such terrain modification, additional capacity demand through site or population expansion, and changes in regulatory requirements and the like. It is thus common to include plans for such secondary or even tertiary systems. Generally, when required the original system is bypassed and the secondary system utilized for the current demands, even though the primary system may retain limited functionality. Further, suitable supplemental drainage may be available only at site elevations higher than the structure discharge elevation, requiring a separate pressurized system with pumping capabilities for transferring the effluent to the raised drain field location.

It would thus be desirable to provide a comprehensive septic system that avoids the above mentioned problems occasioned by temporary or substantial impairment of the original system and to utilize the total available capacity of the overall installation.

Summary of the Invention

The present invention provides a flow control device for the drain lines of a septic system that interrupts the effluent flow in the

event the proximate water table rises to a level of over-saturation thereby directing the effluent flow to the remaining drain lines. Each drain line is provided with a control box having a float controlled inlet valve having an open position allowing flow to the drain line. When the drain line cannot handle the required flow rate or when the proximate water table rises, the float shifts the valve toward a closed position, thereby redirecting the flow to the remaining lines. Multiple drain fields may be coupled thereby utilizing the available capacity of all the installed fields, rather than conversion to a separate system. To assist in sensitive opening and closing, the inlet valve may be provided with a progressively opening and closing sliding valve. During opening, the sliding valve provides an initial pilot valve opening to relieve line pressure followed by main valve opening to provide volumetric flow. During closing, the pilot valve initially closes and the float in conjunction with inlet line pressure moves the valve to a pressure biased closed position.

Accordingly, it is an object of the invention to provide a control system for limiting the flow to a septic drain line under conditions of reduced capacity to avoid ground saturation or penetration.

A further object is to provide a control system for the drain fields in a septic system wherein effluent flow is routed to other drain lines in response to conditions denoting impaired capacity.

Another object is to provide a septic line drain system wherein supplemental capacity can be added without disabling the original installation.

Another object is to control box for septic drain fields wherein a float controlled valve assembly progressively opens and closes to regulate flow from the septic system to the drain lines.

Brief Description of the Drawings

The above and other features and advantages of the present invention will become apparent upon reading the following description taken in conjunction with the accompanying drawing in which:

Figure 1 is a schematic diagram of a septic drain line control system according to an embodiment of the invention;

Figure 2 in a vertical cross sectional view of the control box for the septic drain line control system of Figure 1 with the float valve in the open position;

Figure 3 is an enlarged cross sectional view of the float valve of the control box of Figure 2 with the float valve in the closed position;

Figure 4 is an end view of the distribution box of the control system;

Figure 5 is a schematic diagram of a septic drain line control system according to another embodiment of the invention;

Figure 6 in a schematic elevational view of the control system of Figure 5;

Figure 7 is a cross sectional view of the control box of the control system of Figure 5 with the float valve in the closed position;

Figure 8 is a fragmentary cross sectional view of the control box of the control system of Figure 5 with the float valve in the open position;

Figure 9 is a cross sectional view of a control box in accordance with another embodiment of the invention with the float valve in the closed position;

Figure 1 0 is a fragmentary cross sectional view of the control box of Figure 9 with the float valve in the open position;

Figure 1 1 is a view taken along line 1 1 -1 1 in Figure 10;

Figure 1 2 is an enlarged fragmentary cross sectional view of the control box of Figure 9 with the float valve in the closed position; and

Figure 1 3 is an enlarged fragmentary cross sectional view of the control box of Figure 9 with the float valve in the open position.

Description of the Preferred Embodiments

Referring to Figure 1 , there is shown an embodiment of septic drain line control system 10 having a septic system for handling effluent from a structure 12. The effluent is serially routed from the structure 1 2 along line 14 to a septic tank 1 6. After settling, the effluent is routed along line 1 8 to a distribution box 20. From the distribution box 20, the effluent is routed along main outlet line 22 to feed lines 24 in drain fields 26. Branch lines 28 are connected in parallel with the respective feed lines 24.

Each branch line 28, and optionally the associated feed line 24, is provided with a control box 30 for controlling effluent distribution to the branch line 28 in accordance with the prevailing proximate effluent water table.

Referring to Figures 2 through 4, the control box 30 is a rectangular hollow body having vertically spaced top and bottom walls, 32, 34 respectively, transversely spaced side walls 36, 38 and laterally spaced end walls 40, 42, the inner surfaces of which define a fluid chamber 44.

An inlet line 50 is disposed at the upper center end of end wall 40 and is fluidly connected with feed line 24. A main outlet line 52 in disposed at the lower center end of end wall 42 and is fluidly connected with branch line 28. A secondary line 54 is disposed at the upper center of the end wall 42 and terminated with a ground port for facilitating monitoring and inspection. A plurality of vertically extending weep holes 56 are formed in the box, preferably in the end wall 42, or other locations on the walls. In installation, the control box 30 is disposed in a subterranean cavity of surrounding drain stones. In normal operation, the normal effluent table level 58 is adjacent or below the bottom wall 38 and the effluent in the cavity 44 drains freely through main outlet line 52 for distribution along the length of the branch line 28.

A float control valve assembly 60 is disposed in the box inlet line 50, as a subassembly or unitized assembly. The control valve

assembly 60 includes a flow pipe 62, and a float assembly 64. The float assembly 64 includes a circular valve disc 66 rotatably supported in the flow pipe 62 by horizontal pivot shaft 68. A float assembly 70 including a hollow float 72 is operatively connected by arm 74 to the valve disc 66 and shaft 68. Under normal drainage conditions with the normal water table, the float 72 pivots downwardly until the arm 74 engages the end of the pipe 62 and the valve disc 66 is in the illustrated open position.

Referring to Figure 3, when the water table rises indicative of reduced proximate drainage, the surrounding water flows through holes 56 gradually raising the water level in the cavity to a raised level 76 and moving the valve disc 66 to a closed position blocking the flow of effluent from the distribution tank to the controlled drain line(s). Further pivoting of the disc 66 is blocked by a stop 78 on the inner end of the pipe 62. Sealing gaskets may be employed to further reduce leakage in the closed position. Thereafter, flow from the distribution tank will be preferentially routed to remaining open branch lines. If the water level recedes, the valve assembly will gradually open to resume distribution. In the event sufficient valves close, the effluent will back up to the control box in the line 24

associated with the affected field thereby closing the valve thereat and routing flow to the other field. If both fields are saturated, the effluent will backup through the distribution tank and septic tank and resultantly to the structure, whereat the lack of drainage will effectively signal the need for maintenance or other curative action.

During the course of structure occupancy, the effectiveness of the original septic system may be compromised for various reasons, such as reduction in percolation of the drain lines due to contamination, terrain modification, additional capacity demand through site or population expansion changes in regulatory requirements and the like. It is thus common to include plans for secondary or tertiary systems. Generally, when required the original system is bypassed and the secondary system utilized for the current demands, even though the primary system retains limited functionality. Further, suitable drainage may be available only at site elevations higher than the structure discharge elevation, requiring a separate pressurized system with pumping capabilities for transferring the effluent to the raised drain field location.

A further embodiment for effectively handling the foregoing contingencies is shown in Figures 5 through 8. Referring to Figure

5, a septic line drain control system 100 having a septic system 102 for handling effluent from a structure 104 discharged on outlet line 106. The septic system 102 includes a main tank 1 1 0 having an inlet connected to the outlet line 106 and an outlet connected to a main distribution line 1 1 2. The main distribution line 1 12 is connected with a primary distribution box 1 14 for selectively routing settled effluent from the main tank 1 10 to an original or primary drain system 120. If flow to the primary drain system is blocked or limited, the flow from the primary distribution box 1 14 is routed to a secondary distribution boxl 22 along connector line 124 for routing to a secondary drain system 126. The main distribution line 1 12 includes a Tee fitting 128 upstream of the primary distribution box 126 for routing effluent under conditions described below along branch line 130 to a secondary septic tank 132 for the pressure assisted delivery of effluent to a tertiary drain system 1 34 including a tertiary distribution box 136.

The primary drain system 120 includes drain fields 140, each of which is fluidly connected to the primary distribution box 1 14 by a branch line 141 including a control box 142. The secondary drain system 126 includes drain fields 144, each of which is connected to

the secondary distribution box 1 22 by a control box 142. The tertiary drain system 1 34 includes drain fields 146 connected to the tertiary distribution box 1 36 by a control box 142. The distribution box 1 36 is connected with the tank 1 32 by a supply line 1 50 arid a return line 1 52.

Referring to Figure 6, the main distribution line 1 1 2 flows downwardly below the ground 1 56 from the septic tank 1 10 to the Tee fitting 1 28 to the primary distribution box 1 14 with the indicative relative elevations as depicted. The box 1 14 comprises a thin walled container 166 covered by a lid 168 defining an interior cavity 1 70. Three outlet branch lines 141 fluidly connect the cavity 1 70 with the respective drain fields 140. The connector line 1 24 connects the primary distribution box 1 14 with the secondary distribution box 1 22. The secondary distribution box 1 22 and the tertiary distribution box 136 are similar in construction, with the exception that the connector line connection is not utilized. Where the primary drain field 1 20 is the preferential drainage path, the branch lines 141 are lower than the connector line 1 24 whereby available flow is thereto as the liquid level in the cavity rises until

routed along the connector line to the secondary field. If the preferences are reversed, the relative elevations are reversed.

As representatively shown in Figures 7 and 8, the outlet lines from the various distribution boxes are connected with a control box 142. The control box 142 includes a generally thin wall base 180 having bottom and side walls defining an upwardly opening cavity 1 82 closed by a cover 184. A control valve assembly 1 86 is mounted within the cavity 1 82 on a side wall and connected with a branch line 188 from a related distribution box. A feed line 190 is provided to route effluent to a connected field. Vertical weep holes 1 92 are provided on the side walls for reflecting proximate water table level in the cavity and for modulating the control valve assembly based thereon and exit flow.

The control valve assembly includes a T-shaped valve body 200 slidably supporting a slide valve member 202 including sealing rings 203. The valve member 202 is actuated between an open position shown in Figure 8 and a closed position shown in Figure 7 by a float assembly 204. The valve body 200 has a vertical bore 206 receiving the valve member 202 that is intersected by a center horizontal passage 208 connected with the line 1 88. The float

assembly 204 Includes a float arm 21 0 pivotally connected at a center portion to a vertical bracket 212 at the top of the valve body 200 and pivotally connected at an inner end to an actuator rod 214 connected to a tab 216 on the top of the valve member 202, and supporting a float 21 8 on an outer end whereby the float rises and lowers in response to the fluid level in the cavity 1 82 to shift the valve member 202 between the open position and the closed position thereby controlling the flow of effluent from the outlet line through the valve body passage into the cavity for routing through line 190 to the associated drain field. The float 214 engages to cover 1 84 to establish a stop position in the closed position.

Accordingly, based on local conditions at the control box 142, the float rises in response to cavity liquid level throttling the valve closure limiting available flow to the connected drain field, and routing excess flow to the other fields or to the secondary distribution box, where flow is controlled in a like manner. In the event flow to both the primary and secondary distribution boxes is limited, the liquid level rises to the fitting 1 14 and excess flow is routed through line 1 30 to the secondary tank 1 28. The secondary tank 1 28 includes a float activated pump 220 that directs fluid to

the tertiary distribution box 1 36 along supply line 1 50 and to avoid pressurization thereat return excess fluid to the tank 1 28 along return line 1 52. The flow from the box 1 36 to the control boxes 142 associated with the drain fields 146 of the tertiary system is similar to the operation at the primary and secondary system 120, 126.

It will thus be appreciated that the systems are able to utilize the currently available capacities of the fields of the existing systems, and utilize the tertiary system only as required.

Referring to Figures 9 and 1 0, there is shown a further embodiment of the invention. Therein, a control box 300 for the septic drain system is provided with a progressive float valve assembly 302 for regulating the flow of fluid from an intake line 304 connected to a distribution box as described above. As described below, the float valve assembly includes a pilot valve function that initially opens to relieve the hydrostatic pressure in the intake line, and a main valve function that provides for volumetric flow into the control box and outward to the drain field.

The control box 300 includes a thin wall enclosure or housing 310 having a base 31 2 defining an upwardly opening cavity 314, the

upper end of which is sealed by a cover 316. A wall of the housing includes an opening connected with an outline line 31 8 leading to the drain field. The intake line 304 is mounted on an end wall 320 of the base 31 2 at a mounting flange 322 that is suitably mechanically or adhesively attached to the inner surface of the end wall 320. When the fluid in the cavity 314 is at level 324, the valve assembly 302 is in the closed position as shown in Figure 9. As the fluid level decreases, the valve assembly 302 is progressively opened to the open position shown in Figure 1 0.

The valve assembly 302 is mounted in the cavity 314 at the inner end of the intake line 304. The valve assembly 304 includes a valve body assembly 330 and a float arm assembly 332. The float arm assembly 332 actuates a slide valve assembly 334 in response to changing fluid levels in the cavity 314.

The float arm assembly 332 includes a pivot ring 336 mounted on the inner end of the valve assembly 302. A float arm 338 is pivotally attached to an upper end of the pivot ring 336 at pivot connection 340. The float arm 338 is generally Z-shaped and has a horizontal upper end 344 connected to the pivot ring 336 at the pivot connection 340, a vertical middle section 346, and a

horizontal lower end 348 to which a float 350 is mounted at an upper surface and a counterweight 352 is attached at a lower surface. The middle arm 346 is connected to the slide valve assembly 334 at an actuating link 352.

The valve assembly 302 includes a cylindrical valve body 360 having a stepped counterbore axially therethrough. The outer counterbore telescopically receives the inner end of the intake pipe 304. The middle and inner bores slidably support the slide valve assembly 334.

The slide valve assembly 334 includes an outer or main valve body 362 carrying a progressive valve assembly 364. The valve body 362 includes a front cylindrical collar 370 and a rear cylindrical shaft 372 slidably supported in the inner bore of the valve body 360. A sealing ring 374 is carried on the plug 372 adjacent the collar 370. As shown in Figure 1 1 , the collar 370 includes a circumferential series of axial grooves 376. In the open position shown in Figures 10 and 1 2, the sealing ring 374 is spaced from the base of the counterbore to permit flow through the grooves 376 in the direction of the arrows. In the closed position, the sealing ring 374 engages the base of the front counterbore to prevent flow.

As shown in Figures 1 2 and 1 3, the valve body 362 includes a stepped bore passage therethrough. The pilot valve assembly 364 includes a cylindrical plunger 380 supported in a rear counterbore 382 of the valve body. The link 352 is pivotally connected to the plunger 380 and the middle arm 346 of the lever arm assembly332 as shown in Figures 9 and 1 0. The plunger 380 as shown in Figure 1 3 is spaced from the base of the counterbore at a lost motion connection in the closed position. As shown in Figure 1 2, the plunger 380 engages the base of the counterbore after initial opening movement to shift the valve body 362 to the open position for providing volumetric flow. The plunger 380 of the pilot valve assembly 364 includes a threaded shaft 390 extending axially through the center passage. A pilot valve 392 is adjustably threadably connected to the shaft 390. A sealing ring 394 having an inner diameter larger than the shaft 390 is retained in a groove at the base of the front counterbore. The pilot valve 392 includes a frustoconical tip 396 that engages the sealing ring 394 in the closed position of Figure 1 3. In the open position as shown in Figure 1 2, the tip 396 is spaced from the sealing ring 394 thereby allowing pilot flow in the direction of the arrows. The operation of the valves

and the level 324 may be adjusted by axially shifting the pilot valve on the shaft 390. The plunger 380 includes an outer cylindrical groove 398. The valve body 362 includes radial ports 400 communicating with the groove 398 and allowing flow to the cavity 314 in the open position. An annular clearance is provided in the passage surrounding the shaft 390 and allows flow through ports 402 in the pilot valve assembly 364 in the open pilot position and the main valve position.

In operation, with the valve is in the open position wherein the float valve assembly 332 is in the lowered position shown of Figure 10 and both the main valve and the pilot valve are in the open position, as the fluid level rises, the float 350 rises shifting the link 352 and moving the pilot valve 392 to the closed position blocking flow through the pilot passage. As the in the fluid level further rises, the linkage is further shifted whereby the valve 392 shifts the valve body 362 to the closed position. When the liquid level in the cavity drops, the pilot valve 392 initially opens bleeding the pressure in the intake line and thereafter, the main valve opens to resume flow in the reservoir and outwardly to the drain field.

It will thus be appreciated that the control box provides a progressive valving function to provide sensitive and positive response to changing fluid levels.

Having thus described a presently preferred embodiment of the present invention, it will now be appreciated that the objects of the invention have been fully achieved, and it will be understood by those skilled in the art that many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the sprit and scope of the present invention. The disclosures and description herein are intended to be illustrative and are not in any sense limiting of the invention, which is defined solely in accordance with the following claims.