HK1202147B - Pressure spike reducing apparatus and in-line water hammer arrester - Google Patents

Description

Pressure peak reduction device and coaxial water hammer action prevention device

Technical Field

The present invention relates to an in-line (inline) device for suppressing pressure peaks and reducing "water hammer" noise caused by sudden changes in pressure within a pipe, hose or flexible line when the water flow is shut off.

Background

Water hammer is a common occurrence when there is a sudden change in pressure in a pipe caused by the shut-off of water flow through the pipe. The pressure spike associated with a quick shut-off valve may be 5 times or more the normal pressure within the system. These changes in pressure can cause slapping and shaking of the pipe, creating the typical "hammering" noise associated with the problem, and even in the absence of hammering noise, pressure changes can cause damage to the piping system. Pressure spikes can reflect back from the valve and cause damage to the components of the overall system, including fittings, valves, backflow preventers, and appliances connected to the piping system.

One method of preventing water hammer is by installing a water hammer arrestor. These devices typically comprise a pipe capped at one end, with a piston and a pressurized gas bag between the piston and the capped end, the open end of the pipe being connected to a pipe within the system upstream of which pressure peaks may occur, or to a valve and typically contained in a valve outlet box. The prevention device is typically installed perpendicular to the system piping. When a pressure spike occurs, the pressurized water pushes a piston within the check device, which moves against the compression bag until the pressure stabilizes and the piston returns to its normal, rest position within the check device. This dampens the pressure so that it is not reflected back through the piping system.

This type of prior art water hammer action prevention device works well with a fixed pipe installation but requires additional installation space and a larger size outlet box to accommodate the prevention device. Furthermore, installation is made more difficult by the fact that it typically involves welding tubing, pressure fittings, crimping onto PEX, or other various means of connection. If it is necessary to retrofit piping systems with hammer action prevention devices, the difficulty is increased by making it more difficult to access the pipes in the wall or add hammer action prevention devices at existing outlet boxes. Furthermore, this type of design is not suitable for working with flexible hoses and tubing typically found on washing machines, dishwashers, refrigerators/ice makers, but the valves used with these appliances can cause severe pressure spikes.

Coaxial type preventers are also known, which have advantages over T-connector type preventers, but they use damping material instead of a piston. For example, U.S. patent No.6,672,337 discloses a cushioning diaphragm surrounding a fluid chamber and U.S. patent No.8,307,855 discloses a set of inflatable balloons located within a larger diameter tube for dampening pressure spikes. The piston is more efficient than the cushioning material.

Disclosure of Invention

The water hammer action prevention device disclosed herein can be added to standard and pre-existing flexible hoses and lines commonly found on the supply lines of washing machines, dishwashers, and refrigerators/ice makers. According to one embodiment of the invention, the water hammer prevention device is installed in the pipeline in the flexible hose by crimping or sealing the water hammer prevention device in the middle of the standard hose. Thus the water hammer prevention device is as easy to install for a normal homeowner as a standard hose and can be implemented without professional assistance. Furthermore, the device is relatively small and has a diameter only slightly larger than the usual diameter of a flexible hose supply line of a household appliance (household appliance), so that it can be easily fitted in the same space which accommodates a standard flexible supply line before the supply line is fitted with the prevention means. With the device according to one embodiment of the invention, it is not necessary to install a prevention means in the valve outlet box (valve outlet box), which would allow a smaller box that is less expensive.

According to another embodiment of the invention, the water hammer prevention means comprises a piston and a pressurized gas chamber similar to the prior art device, but the prevention means is coaxial with the system and water passes through the prevention means. This in-line design makes the prevention device compact and easy to install on existing flexible hoses or pipes.

These and other features, objects and advantages of the present invention will be better understood upon consideration of the following detailed description of the preferred embodiments and appended claims, taken in conjunction with the accompanying drawings. While the discussion of the preferred embodiment will focus on using equipment with flexible hoses and piping, the present invention can be used with copper piping, CPVC piping, PEX piping, and other hard surface piping systems with different means of axially connecting the ends of the equipment with these pipes, as will be understood by those of ordinary skill in the art. Furthermore, the present invention may be installed inside an appliance, such as a washing machine or a dishwasher, by the manufacturer of the appliance, as will also be understood by those of ordinary skill in the art.

Drawings

The apparatus of the present invention is further described and explained with reference to the following drawings, in which:

FIG. 1 is a perspective view of one embodiment of an apparatus according to the present invention;

FIG. 2 is a cross-sectional side view of the apparatus of FIG. 1 with the piston in its rest position;

FIG. 3 is a cross-sectional side view of the apparatus of FIG. 2 with the piston in a fully compressed position;

fig. 4 is a cross-sectional side view of the device of fig. 1 connected to a flexible hose.

Detailed Description

Referring to fig. 1, a preferred embodiment of a coaxial water hammer prevention device 10 is depicted. The apparatus 10 preferably comprises: a cylindrical housing 12 having a shoulder 52 at each end; a first end fitting 22; a second end fitting 30; and a longitudinal fluid passage 34. During normal operation of the plumbing system, including systems using hard plumbing materials or flexible hoses or pipes, water flows from the first fitting 22 (upstream or rear end) to the second fitting 30 (downstream or front end). The apparatus 10 is installed upstream from the valve that will close and create a pressure spike. Typically, such valves are part of an appliance with which the prevention device is used. For example, for use with a washing machine, the prevention device 10 is installed in a flexible water supply line between a water supply valve (typically in an open position and not the source of a pressure spike) installed in an outlet box at the wall and the washing machine. Each end fitting 22 and 30 preferably includes a barbed end 24 and 32 extending outwardly beyond the shoulder 52 and a neck portion 21 and 31. Alternatively, the prevention device 10 may be most preferably installed within the appliance by the manufacturer of the appliance, near the appliance valve which may cause a water hammer.

Fig. 2 and 3 depict a preferred embodiment of the prevention device 10. The prevention apparatus 10 includes a housing 12, a first end fitting 22, a second end fitting 30, a piston 14, a pressurized gas chamber 20, and fluid passages 34, 28, and 26. A first end fitting 22 is provided at the upstream end of the housing 12. The first end fitting 22 includes: a cylindrical body 16 having an inner (or downstream) end 40 and a shoulder 41, a cylindrical neck 21 extending outwardly from the shoulder 41, and a barbed end 24. The shoulder 41 abuts a shoulder 52 of the housing 12. The neck 21 extends outwardly (upstream) from the housing 12 through the aperture 54. The barbed end 24 is preferably widest near the neck 21 and tapers as it extends outwardly from the neck 21 to facilitate insertion into the flexible hose, with the widest barbed portion helping to secure the barbed end 24 from removal from the flexible hose. A longitudinal fluid passageway 26 extends through the barbed end 24 and the neck 21. Another fluid passage 28 is formed on the interior of the cylindrical body 16. The fluid channel 28 has a larger diameter than the fluid channel 26. As water flows through the system, fluid (typically water flowing through the plumbing system) is free to flow from the fluid passage 26 to the fluid passage 28. At least one, and preferably at least two, annular grooves 35 are provided in the outer surface of the sidewall of the body 16. Disposed within each annular groove 35 is a seal ring 36 that frictionally engages the inner wall of the housing 12 to secure the first end fitting 22 within the housing 12 and prevent water leakage from between the housing 12 and the first end fitting 22.

The piston 14 is preferably substantially cylindrical. At least one, and preferably at least two, annular grooves 56 are provided in the outer surface of the sidewall of the piston 14. Furthermore, at least one, and preferably at least two, annular grooves 58 are provided in the inner surface of the sidewall of the piston 14. Disposed within each annular groove 56 is a sealing ring 60 that provides slidable engagement between the piston 14 and the inner wall of the housing 12. Disposed within each annular groove 58 is another sealing ring 38 that provides slidable engagement between the piston 14 and the outer wall of the fluid shaft 62. The piston 14 may include a channel disposed between the annular grooves 56 and 58 to facilitate molding. The sealing rings 60 and 38 prevent water and gas from leaking to or from the fluid chamber 28 and the pressurized gas chamber 20.

A second end fitting 30 is provided at the downstream end of the housing 12. The second end fitting 30 includes a generally cylindrical body 18 having an inner (or upstream) end 46 and a shoulder 44, a cylindrical fluid shaft 62, a cylindrical neck 31 extending outwardly from the shoulder 44, and a barbed end 32. At least one, and preferably at least two, annular grooves 35 are provided in the outer surface of the side wall of the body 18 adjacent the inner wall of the housing 12. Disposed within each annular groove 35 is a seal ring 36 that frictionally engages the inner wall of the cylindrical housing 12 to secure the second end fitting 30 within the housing 12 and prevent gas from leaking out of the pressurized gas chamber 20 between the housing 12 and the second end fitting 30. The shoulder 44 abuts a shoulder 52 of the cylindrical housing 12. The neck 31 extends outwardly (downstream) from the housing 12 through the aperture 54. Barbed end 32 is preferably widest near neck 31 and tapers as it extends outwardly from neck 31 to facilitate insertion of the flexible hose, with the widest barbed portion helping to secure barbed end 32 from removal from the flexible hose. The fluid shaft 62 extends inwardly (upstream) from the neck 31. The upstream end 45 of the fluid shaft 62 extends partially into the fluid chamber 28. An annular chamber 48 is formed between the body 18 and the fluid shaft 62. A longitudinal fluid passageway 34 extends through the barbed end 32, the neck 31 and the fluid shaft 62. The fluid passages 26, 28, and 34 cooperate to provide a continuous fluid passage through the prevention apparatus 10. The pressurized gas chamber 20 is formed between the inner wall of the housing 12, the outer wall of the fluid shaft 62, the end 43 of the piston 14, and the end 46 of the body 18. The pressurized gas chamber 20 should meet the latest version of the ASSE1010 test standard to substantially reduce the effects of pressure spikes within the system. Although air is the preferred gas used in the pressurization chamber 20, other gases, preferably inert gases such as nitrogen, may be used.

Under normal operating conditions, when the pressure in the pipe system is stable, the piston 14 is in its rest position close to the first end fitting 22, as shown in fig. 2. The pressure in the pressurized gas chamber 20 is greater than the system pressure, which holds the piston 14 in the rest position. When a pressure spike occurs, the pressure in the system becomes greater than the pressure in the pressurized gas chamber 20, causing the piston 14 to move forward toward the second end fitting 30. Until the piston 14 is moved forward a distance by the pressure created by closing the valve, a portion of the end 42 of the piston 14 abuts the end 40 of the body 16. The piston 14 can be moved forward as needed to adjust for pressure spikes. For sharp peaks, the piston 14 may move forward until the downstream end 43 abuts the end 46 of the second end fitting 30, as shown in fig. 3. Chamber 48 receives gas from chamber 20 as piston 14 advances all the way forward. As the piston is pushed forward from its rest position, a fluid chamber 29 is formed in the area between the inner wall of the housing 12, the end 40, the piston end 42, and the outer wall of the fluid shaft 62, allowing a larger volume of water to fill. As the pressure within the system stabilizes, the piston 14 moves back to its rest position, pushing fluid out of the fluid chamber 29 and back into the fluid passage 28 (and passages 26 and 34), and allowing the gas to expand back into the pressurization chamber 20.

Fig. 4 depicts a preferred embodiment of the water hammer prevention device 10 mounted on a flexible hose. For example, a flexible hose 68 connected to a water supply line and appliance is cut to expose two open ends. A clip or tong-type connector 70 is inserted over each barbed end 24 and 32 and abuts a recessed area (the recessed area being best shown in fig. 1) on the shoulder 52 of the housing 12. The connector 70 preferably has a hose end 76, a neck 72, and a shoulder end 74. The cut end of the hose 68 is inserted into the hose end 76 of the connector 70 and the barbed end 24 is inserted into the cut end of the hose 68 inside the connector 70. The other cut end of the hose 68 is likewise inserted into the hose end 76 of the second connector 70, and the barbed end 32 is inserted into the cut end of the hose 68 inside the second connector 70. Each connector 70 is then crimped or clamped to secure the hose 68 to the holdout device 10. Any other type of connector suitable for use with a flexible hose or tube may be used to connect the hose 68 to the prevention device 10. The device 10 is prevented from being preassembled with the shoulder ends 74 of the connectors 70 attached at both ends of the device 10, both connectors 70 may be prepackaged with the device 10, or the connectors may be purchased separately from the device 10. As will be appreciated by those of ordinary skill in the art, the prevention apparatus 10 may also be used with copper piping, CPVC, PEX, or other hard piping systems with appropriate connectors to connect the prevention device to the piping.

Alternatively, the prevention device 10 may include a screw-type connector, a crimp-type connector, or a clamp-type connector pre-attached to either end fitting 22 and 30 and/or the housing 12 or manufactured integrally with either end fitting 22 and 30 and/or the housing 12. These connectors include washing machines or similar fittings to prevent water leakage. These connectors will mate with similar connectors mounted on flexible hoses or tubing or piping with which the prevention device 10 is used. In this alternative arrangement, the barbed ends 24 and 32 may not be necessary, and may not be required for the necks 21 and 31 to extend outwardly from the housing 12. As another alternative, the prevention device 10 may be integrated with or pre-attached to a flexible hose, pipe, or length of tubing for easier installation. For example, the end of the flexible hose may have a threaded connector ready for connection to the water supply valve and inlet of the washing machine, so that the user need only tighten the connection at the valve and inlet of the washing machine when the prevention device 10 is already in place on the flexible hose, without cutting the hose and without installing the prevention device with a crimp connector. Those of ordinary skill in the art will appreciate the modifications required for such alternative attachment structures.

The first end fitting 22, the second end fitting 30, and the piston 14 are all preferably integrally molded as a single piece. The preferred material for the first end fitting 22, the second end fitting 30, and the piston 14 is acetal (acetal), but other plastic or metal materials, such as polysulfone, polyphenylsulfone (polyphenylsulfone), steel, brass, or other copper alloys, may be used. The seal rings 36, 38 and 60 are preferably standard O-rings. Most preferably, the seal ring 38 is smaller in size than the seal rings 36 and 60, which may be the same size. Furthermore, the annular grooves 35 on the first and second end fittings may be the same size or different sizes, with the sealing ring 36 having corresponding sizes. The housing 12 is most preferably made of stainless steel, but other materials such as copper or aluminum or other metals or plastics may be used.

References herein to forward (or forward) and aft (or rearward) generally refer to the direction of water flow, forward being the downstream direction. After reading this description and the description of the preferred embodiments herein, it will also be understood by those skilled in the art that modifications and changes may be made to the apparatus within the scope of the invention and that it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled.

Claims (28)

1. A pressure spike reduction apparatus comprising:

a housing connectable at each end to a pipe or hose through which fluid can flow, the housing having a fluid passage to allow fluid to flow from the pipe or hose at one end of the housing to the pipe or hose at the other end of the housing;

a piston disposed within the housing and surrounding the fluid passage; and

a pressurized gas chamber disposed within the housing;

a first fitting disposed at an upstream end of the housing and a second fitting disposed at a downstream end of the housing, each fitting comprising a generally cylindrical body disposed within the housing and a neck extending outwardly from the housing, the neck being engageable with the pipe or hose; and

wherein the second fitting further comprises a shaft extending inwardly from the generally cylindrical body, wherein such shaft forms a portion of the fluid passage.

2. The apparatus of claim 1, wherein the piston is generally cylindrical with an outer side wall adjacent an inner wall of the housing and with an inner side wall adjacent an outer wall of the fluid passage;

wherein the piston comprises at least one annular groove disposed within the outer sidewall and at least one annular groove disposed within the inner sidewall; and is

The apparatus further includes a sealing ring disposed in each annular groove to provide slidable sealing engagement between the piston and the housing and the fluid passage.

3. The apparatus of claim 1, wherein the piston is generally cylindrical with an outer side wall adjacent an inner wall of the housing and with an inner side wall adjacent an outer wall of the shaft;

wherein the piston comprises at least one annular groove disposed within the outer sidewall and at least one annular groove disposed within the inner sidewall;

the apparatus further comprises a sealing ring disposed in each annular groove to provide slidable sealing engagement between the piston and the housing and the fluid passage;

wherein the pressurized gas chamber is disposed about the shaft between the downstream end of the piston and the generally cylindrical body of the second fitting;

wherein, when a pressure spike occurs in the conduit, the pressure causes the piston to slide from its rest position adjacent the first fitting towards the second fitting.

4. The apparatus of claim 1, wherein the fluid passage comprises a first passage disposed within the neck of the first fitting, a second passage disposed within the body of the first fitting, a third passage disposed within the shaft, and a fourth passage disposed within the neck of the second fitting.

5. The apparatus of claim 4, wherein the second channel has a larger diameter than the other channels.

6. The apparatus of claim 3, wherein the fluid passage comprises a first passage disposed within the neck of the first fitting, a second passage disposed within the body of the first fitting, a third passage disposed within the shaft, and a fourth passage disposed within the neck of the second fitting when the piston is in its rest position, and further comprising a fifth passage disposed around the third passage and between the second passage and the upstream end of the piston when the piston slides toward the second fitting.

7. The apparatus of claim 1, wherein each fitting further comprises a barbed end disposed at an outer end of the neck.

8. The apparatus of claim 1, wherein the piston, the first fitting, and the second fitting are made of plastic.

9. The apparatus of claim 8, wherein the housing is made of metal.

10. The apparatus of claim 8, wherein the housing is plastic.

11. The apparatus of claim 1, wherein the piston, the first fitting, and the second fitting are made of acetal.

12. The apparatus of claim 9, wherein the metal is stainless steel.

13. The apparatus of claim 1, further comprising: a first flexible hose having a first end disposed at one end of the housing in fluid communication with the fluid passage;

a second flexible hose having a first end disposed at the other end of the housing in fluid communication with the fluid channel;

a threaded connector attached to a second end of each of the first and second flexible hoses for connecting the first flexible hose to a water supply valve and the second flexible hose to an appliance inlet.

14. The apparatus of claim 1, wherein the housing is connected to a fixture water supply line.

15. The apparatus of claim 1, further comprising a threaded connector at each end of the housing, each threaded connector configured to mate with a threaded connector on a hose or pipe to connect the housing to the hose or pipe.

16. A coaxial water hammer prevention device comprising:

a housing;

a first fitting disposed at an upstream end of the housing, including a neck extending outwardly from the housing for engagement with a pipe or hose and a body disposed within the housing;

a second fitting disposed at a downstream end of the housing, including a neck extending outwardly from the housing for engagement with a pipe or hose, a body disposed within the housing, and a shaft extending inwardly from the body;

a piston disposed within the housing between the inwardly facing end of the first fitting and the inwardly facing end of the second fitting and surrounding the shaft;

a pressurized gas chamber disposed within the housing between the downstream end of the piston and an inwardly facing end of a body of a fitting disposed at the downstream end of the housing; and

a fluid passage allowing fluid to flow from an upstream end of the housing through a downstream end of the housing, the fluid passage including an interior portion of the body and neck portions of the shaft and the first and second fittings.

17. The coaxial water hammer prevention device of claim 16, wherein the piston comprises a generally cylindrical body having at least one annular groove disposed within an outer sidewall and at least one annular groove disposed within an inner sidewall;

the preventing means further comprises a sealing ring disposed in each annular groove to provide slidable sealing engagement between the piston and the housing and the shaft.

18. The coaxial water hammer prevention device of claim 17, wherein the piston further comprises a chamber disposed within the generally cylindrical body having an open upstream end allowing fluid communication between the chamber disposed within the generally cylindrical body and a portion of the fluid passage within the body of the first fitting.

19. The coaxial water hammer prevention device of claim 16, further comprising a second chamber disposed between the body and the shaft of the second fitting, the second chamber having an open upstream end allowing fluid communication between the second chamber and the pressurized gas chamber.

20. The coaxial water hammer prevention device of claim 18, further comprising a second chamber disposed between the body and the shaft of the second fitting, the second chamber having an open upstream end allowing fluid communication between the second chamber and the pressurized gas chamber.

21. The coaxial water hammer prevention device of claim 18, wherein the piston is slidable from a rest position of the piston adjacent the body of the first fitting toward the body of the second fitting in response to a pressure spike in a piping system to which the prevention device is connectable.

22. The coaxial water hammer prevention device of claim 16, further comprising two connectors, each connector for connecting each end of the housing to a pipe or hose.

23. The coaxial water hammer prevention device of claim 16, wherein the piston, the first fitting, and the second fitting are made of plastic.

24. The coaxial water hammer prevention device of claim 23, wherein the housing is made of metal.

25. The coaxial water hammer prevention device of claim 23, wherein the housing is plastic.

26. The coaxial water hammer prevention device of claim 16, wherein the piston, the first fitting, and the second fitting are made of acetal.

27. The coaxial water hammer prevention device of claim 24, wherein the metal is stainless steel.

28. The coaxial water hammer prevention device of claim 16, further comprising: a first flexible hose having one end in fluid communication with the upstream end of the fluid channel;

a second flexible hose having one end in fluid communication with the downstream end of the fluid channel; and

a threaded connector attached to the other end of each of the first and second flexible hoses for connecting the first flexible hose to a water supply valve and the second flexible hose to an appliance inlet.