Reciprocating Pump Having a Combination Check Valve and Relief Valve

Abstract

A reciprocating pump having a combination check valve and relief valve is disclosed. The pump includes a pump body having an inlet, an outlet and a pumping chamber. A biasing element provides a force that biases a movable seat toward sealing engagement between a first region of the movable seat and a fixed seat at the inlet. A movable checking element is movable away from a second region of the movable seat when fluid flows in one direction through a passageway in the movable seat. The movable seat also acts as a relief valve wherein the first region of the movable seat disengages the fixed seat if the movable checking element is being forced into engagement with the second region of the movable seat by a force that exceeds the force of the biasing element against a third region of the movable seat.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to reciprocating pumps, and more specifically to diaphragm or piston pumps. In either case, the pump generally has two check valves; a first to allow the material being pumped to enter the pumping chamber, but not to exit, and a second to allow the material to exit the chamber but not to reverse flow and reenter the pumping chamber.

[0002] With electrically operated pumps, in the event the discharge is closed or experiences an obstruction, sometimes referred to as a deadhead situation, the electrically operated pump must be turned off immediately to avoid a potentially dangerous or damaging spike in pressure, or the system must have a relief valve to bleed off the excess pressure created as the pump continues to run.

[0003] In air operated diaphragm pumps, this is not a problem. An air operated pump simply will stall if the back pressure of the pumped material exceeds the air pressure used to move the diaphragms. This is seen as a desirable feature of air operated pumps, both for ease of use and for safety. Although this feature is useful, air operated pumps are very energy inefficient. This prevents them from being widely used for a range of process applications. Nevertheless, the improvements disclosed herein would provide advantages even for installations in air operated pumps.

[0004] The present invention addresses shortcomings in the prior art by disclosing an inlet check valve that is used as both a check valve and a relief valve. This allows reciprocating pumps to continue to run even in a deadhead situation, by preventing the pump motor from stalling or from building dangerous pressure.

SUMMARY OF THE INVENTION

[0005] The disadvantages of the prior art are overcome by examples of reciprocating pumps having a combination check valve and relief valve.

[0006] In a first aspect, the disclosure provides a reciprocating pump having a combination check valve and relief valve. The reciprocating pump includes a pump body having an inlet, an outlet and a pumping chamber in fluid communication between the inlet and the outlet. The reciprocating pump includes a fixed seat at the inlet, and a biasing element seat at the inlet, with a biasing element that engages the biasing element seat. The reciprocating pump also includes a movable checking element, and a movable seat having a passageway therethrough and a first region that engages the fixed seat, a second region that engages the movable checking element, and a third region that engages the biasing element. The biasing element provides a force that biases the movable seat toward sealing engagement between the first region of the movable seat and the fixed seat. The movable checking element is movable away from the second region of the movable seat when fluid flows in one direction through the passageway in the movable seat, and the movable seat acts as a relief valve wherein the first region of the movable seat disengages the fixed seat if the movable checking element is being forced into engagement with the second region of the movable seat by a force that exceeds the force of the biasing element against the third region of the movable seat.

[0007] It follows that the movable seat ceases to act as a relief valve when the force created by the biasing element again becomes greater than the force opposing it.

[0008] In some example embodiments the movable checking element is a ball. In such embodiments, the biasing element may be a spring and the movable seat may move axially against the pump body. For instance, in one embodiment, when the movable seat unseats, it moves axially downward until the pressure is relieved and then moves axially back up to seal.

[0009] In another example embodiment the combination check valve and relief valve is a flapper on a movable seat flapper. This embodiment uses a flapper checking element that pivots to open and allows flow to pass. This checking element seals against a movable seat in the form of a flapper that is biased to a sealing position against the pump body by a torsion spring. The flapper checking element would operate as a standard check valve until the force provided by the working pressure in the pump chamber exceeds the spring force. In such an event, the movable seat flapper would pivot to an open position and act as a pressure relief valve. Once the force due to the pressure drops sufficiently, the movable seat flapper reseals against the pump body.

[0010] It is to be understood that both the foregoing general description and the following detailed description are exemplary and provided for the purpose of explanation only, and are not restrictive of the subject matter claimed. Further features and objects of the present disclosure will become more fully apparent in the following description of the preferred embodiments and from the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In describing the preferred example embodiments, reference is made to the accompanying drawing figures wherein like parts have like reference numerals, and wherein:

[0012] FIG. 1 shows a section view of a first example piston pump.

[0013] FIG. 2 shows a detailed section view of a first example combination check valve and relief valve shown in FIG. 1.

[0014] FIG. 3 shows a detailed section view of the first example combination check valve and relief valve shown in FIG. 2, but with a biasing element spacer.

[0015] FIG. 4 shows a detailed section view of the first example combination check valve and relief valve shown in FIG. 2, but with a biasing element adjustable spacer.

[0016] FIG. 5 shows a section view of a double diaphragm pump with a second combination check valve and relief valve as a left hand inlet valve and a third example combination check valve and relief valve as a right hand inlet valve.

[0017] FIG. 6 shows a detailed view of the second combination check valve and relief valve of the left hand inlet valve shown in FIG. 5.

[0018] FIG. 7 shows a detailed view of the third combination check valve and relief valve of the right hand inlet valve FIG. 5.

[0019] FIG. 8 shows a section view of an alternative single diaphragm pump with a fourth example combination check valve and relief valve in the form of a flapper valve having a flapper valve seat.

[0020] It should be understood that the drawings are not to scale. While some mechanical details of the example pumps, including details of fastening means and other plan and section views of the particular components, may not have been shown, such details are considered to be within the comprehension of those skilled in the art in light of the present disclosure. It also should be understood that the present disclosure and claims are not limited to the preferred embodiments illustrated.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0021] Referring generally to FIGS. 1-8, it will be appreciated that the combination check valve and relief and valve assemblies of the present disclosure generally may be embodied within numerous configurations. Indeed, the teachings within this disclosure may pertain to a combination check valve and relief valves for use in various types of reciprocating pumps.

[0022] FIGS. 1-4 show the invention in a first preferred example embodiment as integrated into a single piston pump 1. In this example, as seen in FIG. 1, the pump 1 includes a pump body 2 that may further include an assembly of a central portion 3, an upstream portion 4 and a downstream portion 5. The example pump 1 also has an inlet 6 and an outlet 7 in fluid communication with a pumping chamber 8. A pumping element 8a, in the form of a piston, is in communication with and displaceable within the pumping chamber 8. The pump 1 further is shown as including a check valve assembly 9 at the outlet 7.

[0023] At the inlet 6, the pump 1 has a combination check valve and relief valve 10, which includes a fixed seat 11 at the inlet 6, a biasing element seat 12 at the inlet 6, a biasing element 13 in the form of a compression spring that engages the biasing element seat 12, a movable checking element 14, and a movable seat 15 having a passageway 16 therethrough. The movable seat 15 has a first region 15a that engages the fixed seat 11, a second region 15b that engages the movable checking element 14, and a third region 15c that engages the biasing element 13.

[0024] In this first example embodiment, the biasing element 13 is pre-compressed against the biasing element seat 12 during assembly of the central portion 3 and upstream portion 4 of the pump body 2. This forces the first region 15a on a first face 15d of the movable seat 15 into sealing engagement against the fixed seat 11 in the inlet 6. The second region 15b is effectively on the first face 15d of the movable seat 15 and engages the movable checking element 14, and the third region 15c is on an opposed second face 15e of movable seat 15 that engages the biasing element 13.

[0025] The pre-compression in FIG. 2 of the biasing element 13 is set so that under standard pumping conditions the movable seat 15 remains in engagement with the fixed seat 11 at the first region 15a. The movable checking element 14 is movable axially away from the second region 15b of the movable seat 15 when fluid flows in one direction through the passageway 16 in movable seat 15, so as to have fluid flow through the inlet 6 into the pumping chamber 8. In the event that back pressure on the valve 10 is increased sufficiently, the material being pumped will push downward on the movable seat 15 and on the movable checking element 14 with a force greater than the force that the biasing element 13 is exerting on the third region 15c of the movable seat 15. This will break the sealing engagement between the first region 15a of the moveable seat 15 and the fixed seat 11 and move the movable seat 15 axially away from the fixed seat 11, and the material being pumped will leak back to the inlet 6 around movable seat 15, thereby reducing the pressure. When the pressure lowers to the point where the force that the biasing element 13 exerts on the movable seat 15 is greater than the force provided by the pressure above the movable seat 15, the movable seat 15 will be forced axially upward and into sealing engagement against the fixed seat 11.

[0026] It will be appreciated that it is contemplated that pumps could have multiple inlets and/or outlets and the one or more inlets could have multiple combination check valve and relief valves. In addition, a combination check valve and relief valve could include multiple components, as desired, such as with respect to fixed seats, biasing element seats, biasing elements, checking elements, and movable seats.

[0027] In FIG. 3, the force generated by the biasing element 13 may be adjusted. In this example, the force may be adjusted by a fixed amount by displacing the biasing element 13, such as by adding a biasing element spacer 17 to effectively displace the biasing element seat 12. To adjust the pre-compression force, such a biasing element spacer 17 may be replaced by a spacer having a different thickness, or a plurality of spacers may be stacked to gain a different amount of displacement.

[0028] In FIG. 4, the force generated by the biasing element 13 may be adjusted by moving the biasing element seat 13 via movable displacement that may be applied by an adjustment screw 18, so as to effectively displace the biasing element seat 12. Thus, turning the adjustment screw 18 to advance toward the biasing element 13 effectively displaces the biasing element seat 12 to increase the compression in the biasing element 13.

[0029] Turning to FIG. 5, a second example embodiment of a reciprocating pump is shown in an example double diaphragm pump 101. The pump 101 includes a pump body 102 that may further include an assembly of a central portion 103, an upstream portion 104 and a downstream portion 105. The second example pump 101 may be seen as having a left hand side and a right hand side, which in this example are intended to show two additional versions of a combination check valve and relief valve that are more closely shown in FIGS. 6 and 7.

[0030] As shown in FIGS. 5 and 6, the left hand side of the pump 101 includes an inlet 106 and an outlet 107 in fluid communication with a pumping chamber 108. A pumping element 108a, in the form of a diaphragm, is in communication with and is displaceable within the pumping chamber 108. The pumping element 108a on the left hand side is connected by a shaft 119 to a pumping element 108a' on the right hand side of the pump 101, with the shaft 119 being slidable within a drive assembly 120. The left hand side of the second example pump 101 further is shown as including a check valve assembly 109 at the outlet 107.

[0031] At the inlet 106, the pump 101 has a combination check valve and relief valve 110, which includes a fixed seat 111 at the inlet 106, a biasing element seat 112 at the inlet 106, a biasing element 113 in the form of a tension spring that engages the biasing element seat 112 at a shaft 118, a movable checking element 114, and a movable seat 115 having a passageway 116 therethrough. The movable seat 115 has a first region 115a on a first face 115d of the movable seat 115 that engages the fixed seat 111, a second region 115b is effectively on the first face 115d of the movable seat 115 and engages the movable checking element 114, and a third region 115c is on the first face 115d of the movable seat 115 that engages the biasing element 113, with no engagement of an opposed second face 115e of the movable seat 115.

[0032] In FIG. 6, the pre-compression is supplied by the tension of the biasing element 113, which is set so that under standard pumping conditions the movable seat 115 remains in engagement with the fixed seat 111 at the first region 115a. The movable checking element 114 is movable axially away from the second region 115b of the movable seat 115 when fluid flows in one direction through the passageway 116 in movable seat 115, so as to have fluid flow through the inlet 106 into the pumping chamber 108. In the event that back pressure on the valve 110 is increased sufficiently, the material being pumped will push downward on the movable seat 115 and on the movable checking element 114 with a force greater than the force that the biasing element 113 is exerting on the third region 115c of the movable seat 115. This will break the sealing engagement between the first region 115a of the moveable seat 115 and the fixed seat 111 and move the movable seat axially away from the fixed seat 111, and the material being pumped will leak back to the inlet 106 around movable seat 115, thereby reducing the pressure. When the pressure lowers to the point where the force that the biasing element 113 exerts on the movable seat 115 is greater than the pressure above the movable seat 115, the movable seat 115 will be forced axially upward and into sealing engagement against the fixed seat 111.

[0033] As shown in FIGS. 5 and 7, the right hand side of the pump 101 includes an inlet 106' and an outlet 107' in fluid communication with a pumping chamber 108'. A pumping element 108a', in the form of a diaphragm, is in communication with and displaceable within the pumping chamber 108' and is connected to the shaft 119. The right hand side of the second example pump 101 further is shown as including a check valve assembly 109' at the at least one outlet 107'.

[0034] At the inlet 106', the pump 101 has a combination check valve and relief valve 110', which includes a fixed seat 111' at the inlet 106', a biasing element seat 112' at the inlet 106', a first biasing element 113' in the form of a compression spring that engages the biasing element seat 112', a movable checking element 114' in the form of a poppet, and a movable seat 115' having a passageway 116' therethrough. The movable seat 115' has a first region 115a' on a the first face 115d' of the movable seat 115' that engages the fixed seat 111', a second region 115b' is effectively on the first face 115d' of the movable seat 115' and engages the movable checking element 114', and a third region 115c' is on a second face 115e' of the movable seat that engages the first biasing element 113'.

[0035] In FIG. 7, the pre-compression is supplied by the compression of the first biasing element 113', which is set so that under standard pumping conditions the movable seat 115' remains in engagement with the fixed seat 111' at the first region 115a'. The movable checking element 114' is movable axially away from the second region 115b' of the movable seat 115' when fluid flows in one direction through the passageway 116' in movable seat 115', so as to have fluid flow through the inlet 106' into the pumping chamber 108'. In this example, with the checking element 114' in the form of a poppet, a second biasing element 121' is provided in the form of a smaller spring having a lower spring force than the spring force of the first biasing element 113' and the second biasing element 121' engages a second biasing element seat 122'. In this example, In the event that back pressure on the valve 110' is increased sufficiently, the material being pumped will push downward on the movable seat 115' and on the movable checking element 114' with a force greater than the force that the first biasing element 113' is exerting on the third region 115c' of the movable seat 115'. This will break the sealing engagement between the first region 115a' of the moveable seat 115' and the fixed seat 111' and move the movable seat 115' axially away from the fixed seat 111', and the material being pumped will leak back to the inlet 106' around movable seat 115', thereby reducing the pressure. When the pressure lowers to the point where the force that the first biasing element 113' exerts on the movable seat 115' is greater than the force provided by the pressure above the movable seat 115', the movable seat 115' will be forced axially upward and into sealing engagement against the fixed seat 111'.

[0036] Turning to FIG. 8, third example embodiment of a reciprocating pump is shown in an example single diaphragm pump 201. The pump 201 includes a pump body 202 that may further include an assembly of a central portion 203, an upstream portion 204 and a downstream portion 205. The third example pump 201 utilizes flapper valve elements. The pump 201 includes an inlet 206 and an outlet 207 in fluid communication with a pumping chamber 208. A pumping element 208a, in the form of a diaphragm, is in communication with and displaceable within the pumping chamber 208. The pumping element 208a is connected to a shaft 219 which is slidable within a drive assembly 220. The third example pump 201 further is shown as including a check valve assembly 209 at the outlet 207.

[0037] At the inlet 206, the pump 201 has a combination check valve and relief valve 210, which includes a fixed seat 211 at the inlet 206, a biasing element seat 212 at the inlet 206, a biasing element 213 in the form of a torsion spring that acts rotationally and engages the biasing element seat 212, a movable checking element 214 in the form of a flapper, and a movable seat 215 in the form of a flapper that is movable rotationally and has a passageway 216 therethrough. The movable seat 215 has a first region 215a that engages the fixed seat 211, a second region 215b that engages the movable checking element 214, and a third region 215c that engages the biasing element 213.

[0038] In this third example embodiment, the biasing element 213 is pre-compressed against the biasing element seat 212 during assembly within the upstream portion 204 of the pump body 202. This forces the first region 215a on a first face 215d of the movable seat 215 into sealing engagement against the fixed seat 211 in the inlet 206. The second region 215b on the first face 215d of the movable seat 215 engages the movable checking element 214, and the third region 215c on an opposed second face 215e of movable seat 215 engages the biasing element 213.

[0039] The pre-compression in FIG. 8 of the biasing element 213 is chosen and so that under standard pumping conditions the movable seat 215 remains in engagement with the fixed seat 211 at the first region 215a. The movable checking element 214 in the form of a flapper is movable rotationally away from the second region 215b of the movable seat 215 by pivoting when fluid flows in one direction through the passageway 216 in movable seat 215, so as to have fluid flow through the inlet 206 into the pumping chamber 208. In the event that back pressure on the valve 210 is increased sufficiently, the material being pumped will push rotationally on the movable seat 215 and on the movable checking element 214 with a force greater than the force that the biasing element 213 is exerting on the third region 215c of the movable seat 215. This will break the sealing engagement between the first region 215a of the moveable seat 215 and the fixed seat 211, and the material being pumped will leak back to the inlet 206 around movable seat 215, thereby reducing the pressure. When the pressure lowers to the point where the force that the biasing element 213 exerts on the movable seat 215 is greater than the force provided by the pressure above the movable seat 215, the movable seat 215 will be forced rotationally forward into sealing engagement against the fixed seat 211.

[0040] Once again, regardless of the particular example embodiment, it will be appreciated that pumps could have multiple inlets and/or outlets and the one or more inlets could have multiple combination check valve and relief valves, and that a combination check valve and relief valve could include multiple components, as desired, such as with respect to fixed seats, biasing element seats, biasing elements, checking elements, and movable seats.

[0041] From the above disclosure, it will be apparent that pumps constructed in accordance with this disclosure may include a number of structural aspects that provide advantages over conventional constructions, depending upon the specific design chosen.

[0042] It will be appreciated that reciprocating pumps having a combination check valve and relief valve may be embodied in various configurations with respect to the type of pump, as well as various configurations of a combination check valve and relief valve. Any variety of suitable materials of construction, configurations, shapes and sizes for the components and methods of connecting the components may be utilized to meet the particular needs and requirements of an end user. It will be apparent to those skilled in the art that various modifications can be made in the design and construction of such reciprocating pumps having a combination check valve and relief valve without departing from the scope or spirit of the claimed subject matter, and that the claims are not limited to the preferred embodiment illustrated herein.

Claims

1. A reciprocating pump having a combination check valve and relief valve, comprising: a pump body further comprising an inlet, an outlet and a pumping chamber in fluid communication between the inlet and the outlet; a fixed seat at the inlet; a biasing element seat at the inlet; a biasing element that engages the biasing element seat; a movable checking element; a movable seat having a passageway therethrough and a first region that engages the fixed seat, a second region that engages the movable checking element, and a third region that engages the biasing element; wherein the biasing element provides a force that biases the movable seat toward sealing engagement between the first region of the movable seat and the fixed seat, the movable checking element is movable away from the second region of the movable seat when fluid flows in one direction through the passageway in the movable seat, and the movable seat acts as a relief valve wherein the first region of the movable seat disengages the fixed seat if the movable checking element is being forced into engagement with the second region of the movable seat by a force that exceeds the force of the biasing element against the third region of the movable seat.

2. The reciprocating pump of claim 1, wherein the movable seat has first and second faces.

3. The reciprocating pump of claim 2, wherein the first and second faces are on opposed sides of the movable seat.

4. The reciprocating pump of claim 2, wherein the first and second regions of the movable seat are located on the first face of the movable seat, and the third region of the movable seat is located on the second face of the movable seat.

5. The reciprocating pump of claim 2, wherein the first, second and third regions of the movable seat are located on the first face of the movable seat.

6. The reciprocating pump of claim 1, wherein the biasing element is a compression spring, a tension spring or a torsion spring.

7. The reciprocating pump of claim 1, wherein the biasing element force is adjustable.

8. The reciprocating pump of claim 7, wherein the biasing element force is adjusted by displacement of the biasing element seat.

9. The reciprocating pump of claim 8, wherein the biasing element seat is displaceable by a screw or spacer.

10. The reciprocating pump of claim 1, wherein the movable checking element is a ball, a flapper or a poppet.

11. The reciprocating pump of claim 1, wherein the movable checking element is movable axially or rotationally.

12. The reciprocating pump of claim 1, wherein the movable seat is movable axially or rotationally.

13. The reciprocating pump of claim 1, wherein the movable checking element is forced into engagement with the second region of the movable seat by a second biasing element.

14. The reciprocating pump of claim 13, wherein the second biasing element has a lower spring force that the first biasing element.

15. The reciprocating pump of claim 13, wherein the second biasing element engages a second biasing element seat in the inlet.

16. The reciprocating pump of claim 1, wherein the reciprocating pump further comprises a piston in communication with the pumping chamber.

17. The reciprocating pump of claim 1, wherein the reciprocating pump further comprises a diaphragm in communication with the pumping chamber.