US3333597A

US3333597A - Automatic primer valve for drain traps

Info

Publication number: US3333597A
Application number: US409173A
Authority: US
Inventors: Richard N Sullivan
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-11-05
Filing date: 1964-11-05
Publication date: 1967-08-01
Anticipated expiration: 1984-08-01

Description

g- 1, 1957 R. N. SULLIVAN 3,333,597

AUTOMATIC PRIMER VALVE FOR DRAIN TRAPS Filed Nov. 5, 1964 INVENTOR.

RICHARD N. SULLWAN United States Patent 3,333,597 AUTOMATIC PRllVIER VALVE FOR DRAIN TRAPS Richard N. Sullivan, 1843 SE. 60th Ave., Portland, Oreg. 97215 Filed Nov. 5, 1964, Ser. No. 409,173 8 Claims. (Cl. 137-102) This invention relates to a valve for supplying a small amount of water periodically to a drain trap.

When a drain is used infrequently, the water in its trap evaporates allowing sewer gas to enter the building. It is, therefore, necessary to provide an automatic device for supplying water periodically to the drain trap to keep it filled. Various types of primer valves have heretofore been developed and used for this purpose but all of them are subject to one or more objections.

Two of the main objections to conventional primer valves are the use of metal springs and the requirement that they be installed directly in a supply pipe. Metal springs are objectionable because they must be adjusted to a particular water pressure and because they lose their resilience in time. Variations in pressure in the supply main render them inoperative. A primer valve in a sup ply pipe is objectionable because in many buildings the supply pipe is remote to some of the drains which must be primed. Other objections to conventional primer valves are their complex construction, high cost and general lack of reliability over a long period of time.

The general object of the present invention is, therefore, to provide an automatic primer valve which overcomes the above-mentioned objections. Particular objects are to provide a primer valve without springs or at least without a calibrated spring, to provide a primer valve which is not connected in the flow of a water supply line, to provide a primer valve which may be connected to a small branch line, to provide a primer valve which is self-compensating for changes in main pressure and to provide a primer valve which is relatively simple and inexpensive to manufacture but which is durable and reliable in operation. 7

In certain preferred embodiments the present primer valve is actuated by the spring action of a pocket of compressed air. The air is compressed by the normal water pressure and when the water pressure is reduced, as by the opening of a faucet, the expansion of the air releases a small quantity of water suificient to rebalance the air pressure against the reduced water pressure. A modification shows a spring substituted for the air pressure but the arrangement is such that the spring does not have to be calibrated.

The foregoing and other objects and advantages will become apparent and the invention will be better understood from the following description of the preferred embodiments illustrated on the accompanying drawing. Various changes may be made, however, in the details of construction and arrangement of parts and certain features may be used without others. All such modifications within the scope of the appended claims are included in the invention.

In the drawing:

FIGURE 1 is a sectional view of a primer valve embodying the features of the invention, the valve being in closed position;

FIGURE 2 is a fragmentary view similar to FIGURE 1, showing the valve in open position;

FIGURE 3 is a view similar to FIGURE 2, showing a modification;

FIGURE 4 is a view showing the valve installed in a typical plumbing system;

FIGURE 5 is a fragmentary view of another modification; and

"ice

FIGURE 6 is a fragmentary view of still another modification.

FIGURE 4 illustrates why a primer valve is necessary. The floor drain 10 is connected through a drain trap 11 and drain pipe 12 with a sewer pipe 13. If the water evaporates from trap 11, sewer gas can enter the building. Drying of the trap 11 is prevented by the primer valve 15 which supplies water periodically through a pipe 16. The primer valve is supplied by a small branch pipe 17 connected to a water supply pipe 18 leading to the faucet 20. In this installation, the drain is relatively close to the supply pipe 18 but, in many cases, the nearest supply pipe may be quite remote.

Whenever a faucet or other valve is opened anywhere in the building, there is a drop in pressure in branch pipe 17 and this drop in pressure, however small, is utilized to actuate the primer valve 15 to release a small amount of water through pipe 16 to the trap 11. One of the advantages of the present primer valve is that it may be located anywhere between the supply pipe 18 and trap 11, and the connecting pipes 16 and 17 may be of relatively small size since the flow throughthese pipes is negligible in relation to the flow through pipe 18 when water is being used for normal purposes.

Referring now to FIGURE 1, the primer valve 15 is incorporated in a hollow body 25 having a flexible diaphragm 26 which forms an upper or supply chamber 27 and a lower or dispensing chamber 28. For convenience in manufacture, the periphery of the diaphragm is secured -to a cap member 29 having a recess which forms the chamber 27. Branch pipe 17 is connected with cap 29 and communicates with chamber 27 through a screen 30.

The center of the diaphragm is apertured to receive a short tube 3-5 having a flanged head 36 on its upper end. Tube 35 is secured by a press fit in a tube 37 so that the diaphragm is clamped between the upper end of tube 37 and flange 36. The lower end of tube 37 has an annular valve surface 38 which seats on a resilient washer 39 supported on a shoulder 40 in the lower end of body 25. A pilot extension 41 on the lower end of tube 37 projects through washer 39 to serve as a guide for tube 37 and prevent the tube from cocking in an inclined position. Tube 37 has openings 42 in the lower portion of its side wall and contains a float valve 43 which is adapted to seat against a resilient washer 44 at the lower end of tube 35.

The lower end of body 25 has an extension 50 for connection with pipe 16 and this extension is provided with vacuum breaker or anti-syphoning openings 51. A vertical air tube 52 has an angular fitting on its lower end with a nipple 55 for connection with body 25 and communication through a side passage 53 with the chamber 28.

When no water is being drawn in the building, the static water pressure in chamber 27 presses diaphragm 26 downward, holding valve surface 38 seated against washer 39 to prevent any flow of water through the device, as shown in FIGURE 1. Tube 52 is full of water except for a pocket of trapped air at its upper end which is compressed by the water pressure. Chamber 28 and tube 37 are full of water with the float 43 bearing lightly against the washer 44 by reason of the buoyancy of the float.

When a faucet or other valve is opened anywhere in the building allowing water to flow, there is a reduction in pressure in branch pipe 17 allowing diaphragm 26- to move upward to its FIGURE 2 position under the pressure exerted by the trapped air compressed in the upper end of tube 52. It will be appreciated that any reduction in pressure on the upper side of the diaphragm will cause the float 43 to seat more firmly against washer 44 as a check valve to prevent any equalization of pressures through tube 35. Thus, the lifting of diaphragm 26 unseats the valve surface 38 from washer 39 to allow equalizationof pressure by escape of a small amount of water through the washer and into discharge connection 50'.

This discharge of water allows the trapped air in the upper end of tube 52 to expand until its pressure, exerted through chamber 28, isinsuflicient to hold the diaphragm deflected upward against the pressure in chamber 27. When this occurs, the diaphragm is again deflected downward to its FIGURE 1 position, closing the valve surface 38 against washer 39. Regardless of how long the reduction in pressure may persist in pipe 17, no more water will be discharged into trap 11. The amount of water discharged into the trap varies with the pressure drop in pipe 17 and is normally a spoonful or two. This small amount released many times a day more than compensates for evaporation loss from the trap but does not waste an appreciable amount of water. The valve 38 does i not remain open long enough for the entire contents of chamber 28 and tube 52 to discharge.

When the opened faucet or valve has been closed, restoring normal static pressure to chamber 27, the pressure on the upper side of the diaphragm becomes momentarily higher than the pressure on the lower side. This pressure differential unseats float valve 43 as shown in FIGURE 1 until sufiicient water has flowed into tube 52 to compress the trapped air at the top of the tube back to a volume where its pressure balances the pressure in chamber 27. Then float 43 reseats on washer 44 with a light force corresponding merely to the buoyancy of the float. The trapped air in the upper end of tube 52 remains there permanently. Valve 43 may be biased to closed position by a light spring instead of buoyancy, if desired.

It will be observed that different effective areas of the diaphragm are exposed to the pressures in

chamber

27 and 28, This permits the sensitiveness of the diaphragm to small pressure drops in pipe 17 to be controlled by the choice of dimensions for the inside diameter of tube 35 and the wall thicknesses of the two

tubes

35 and 37. The device may thus be made as sensitive as desired to respond to very small pressure drops in branch pipe 17. The trapped air in tube 52 provides the spring pressure for raising the diaphragm and is automatically self-adjusting to changes in the water main pressure.

Float valve 43 permits complete draining of the system to prevent freezing in cold weather. When pressure in pipe 18 is reduced to atmospheric pressure, the water will run out of tube 52 and chamber 28. Water remaining in branch pipe 17 has insufiicient pressure to hold valve 38 firmly seated whereby this water also will gradually leak away to the drain trap 11. If desired, a nail may be inserted through openings 51 to lift the stem 41 and hold valve 38 open. Instead of utilizing buoyancy to hold check valve 43 closed, a light spring may be employed if desired.

FIGURE 3 shows a modification 15A having a piston 26a in place of the diaphragm 26. In all other respects, the construction and operation are the same as described in connection with FIGURES land 2. The term diaphragm in the appended claims includes a piston-type diaphragm as well as a flexible-type diaphragm.

In some cases it may be found that there is a tendency for the trapped air in the top of tube 52 to dissolve in the water over a period of time and reduce the effectiveness of the air spring. This is prevented in FIGURE 5 where the air chamber 56 is separated from water chamber 57 by a flexible diaphragm 60.

Also, if desired, a metal spring 61, inFIGURE 6, may be substituted for the air spring in FIGURES 1 to 5. The metal spring performs the same function as the air 7 spring and is not objectionable as the metal springs in conventional primer valves because it does not require calibration or adjustment. The spring chamber is vented to atmosphere at 62 or a combination of air spring and metal spring may be employed by omitting the vent 62.

.means comprising an air The parts not shown in FIGURES 5 and 6 may be the same as shown in FIGURE 2 or FIGURE 3.

The present valve in all of its modifications responds also to any pressure shock or water hammer in the out side main as well as gradual changes in outside main pressure. This insures that the drains will be kept primed in an unoccupied building where the faucets are not being pressure on said diaphragm'in said supply chamber to close said outlet, an opening between said two chambers,

a check valve in said opening permitting flow from said supply chamber to said dispensing chamber and preventing back flow, and resilient means arranged to be compressed by the water pressure in said dispensing chamber and maintain pressure in said dispensing chamber to hex said diaphragm and open said outlet valve whenever the pressure is reduced in said supply chamber.

2. A primer valve as defined in claim 1, said resilient means comprising a trapped air chamber connected with said dispensing chamber. 7

3. A primer valve as defined in claim 1, said resilient chamber and a flexible diaphargm closing one side of said chamber, said diaphragm being exposed on one side to the Water pressure in said dispensing chamber to compress the air in said air chamber.

4. A primer valve as defined in claim 1, said resilient means comprising a spring engaging one side of a flexible diaphragm, the opposite side of said diaphragm being exposed to the water pressure in said dispensing chamber to compress said spring.

5. A primer valve comprising a pair of chambers sepa-' pair of chambers, and a check valve in said opening independent of said outlet valve permitting flow from said first chamber to said second chamber and preventing back flow.

6. A primer valve comprising a supply chamber and a dispensing chamber separated by a diaphragm, an inlet connection in said supply chamber, an outlet in said dispensing chamber, a valve operable by movement of said diaphragm under pressure in said supply chamber to close said outlet, a trapped air chamber connected with said dispensing chamber, an opening between said supply and dispensing chambers, and a check valve in said ope'ning independent of said outlet valve permitting flow from said supply chamber to said dispensing chamber and preventing back flow.

7. A primer valve comprising a supply chamber and a dispensing chamber separated by a diaphragm, an inlet connection in said supply chamber, an outlet in said dispensing chamber, a tubular member in said dispensing chamber connected with said diaphragm and having a valve portion to close said outlet, an opening through said diaphragm into said tubular member, an opening in said tubular member Within said dispensing chamber,:a float valve in said tubular member for said diaphragm opening, and an air chamber connected with said dispensing chamber and extending above said dispensing chamber.

S. A primer valve comprising a chambered body member having an open end, a chambered cap on said open end of said body member, a diaphragm separating said two chambers, a water supply connection for said cap chamber, an outlet in said body chamber having a valve seat, a tubular member connected at one end to said diaphragm and having a valve on its other end to cooperate with said seat, an opening in said tubular member within said body chamber, an opening in said diaphragm having a valve seat Within said tubular member, a float valve in said tubular member engageable with said last seat, and

an air chamber communicating at its lower end with said body chamber,

References Cited 5 UNITED STATES PATENTS 2,233,818 3/1941 Matter 137-l 15 2,938,530 5/1960 Matter 137l15 WILLIAM F ODEA, Primal Examiner. 10 D. J. ZOBKIW, Assistant Examiner.

Claims

1. A PRIMER VALVE COMPRISING A SUPPLY CHAMBER AND A DISPENSING CHAMBER SEPARATED BY A FLEXIBLE DIAPHRAGM, A WATER INLET CONNECTION IN SAID SUPPLY CHAMBER, AN OUTLET IN SAID DISPENSING CHAMBER, A VALVE OPERABLE BY PRESSURE ON SAID DIAPHRAGM IN SAID SUPPLY CHAMBER TO CLOSE SAID OUTLET, AN OPENING BETWEEN SAID TWO CHAMBERS, A CHECK VALVE IN SAID OPENING PERMITTING FLOW FROM SAID SUPPLY CHAMBER TO SAID DISPENSING CHAMBER AND PREVENTING BACK FLOW, AND RESILIENT MEANS ARRANGED TO BE COMPRESSED BY THE WATER PRESSURE IN SAID DISPENSING CHAMBER AND MAINTIAN PRESSURE IN SAID DISPENSING CHAMBER TO FLEX SAID DIAPHRAGM AND OPEN SAID OUTLET VALVE WHENEVER THE PRESSURE IS REDUCED IN SAID SUPPLY CHAMBER.