Duplex strainer apparatuses, systems and methods

Duplex fluid strainers, systems and methods are provided, and include a housing with a first valve chamber defining an inlet port, a first port, and a second port, and a second valve chamber defining a third port, a fourth port, and an outlet port. The first and third ports communicate with a first strainer chamber, and the second and fourth ports communicate with a second strainer. A first seal assembly includes a first disk movable within the first valve chamber into sealing engagement against either of the first port or the second port, and a second seal assembly includes a second disk movable within the second valve chamber into sealing engagement against either of the third port or the fourth port.

TECHNICAL FIELD

The subject matter disclosed herein relates generally to a fluid strainer for use in a fluid piping system. More particularly, the subject matter disclosed herein relates to duplex strainer apparatuses, systems and methods for providing multiple straining flow paths.

BACKGROUND

In many fluid flow applications, it is often necessary that the flow from an upstream source be cleaned or strained before use in downstream components. In this regard, strainers are used to protect such downstream equipment by mechanically removing solids from flowing fluids via a straining element, such as a perforated, mesh, or wedge-wire straining element. Although many designs and configurations of strainers exist, duplex strainers provide an added advantage over other straining systems by permitting continuous straining and cleaning of a flow. Specifically, duplex strainers generally include two strainer chambers and some type of mechanism for diverting the flow from one chamber to the other to isolate the flow to a single chamber. This arrangement permits cleaning, servicing, or repairing of one chamber while the other one is in use, thereby enabling the flow through the duplex strainer to remain substantially continuous.

A number of different designs for duplex strainers have been used, with varying valve designs (e.g., scotch yokes, ball valves) for switching the flow between strainers, but each design both has advantages over other options and suffers from one or more problems, such as number and complexity of components, space requirements, effectiveness in flow isolation, and/or ease of operation. Accordingly, an improved duplex strainer is desirable, for example one with a design to effectively control the flow between and among multiple strainer assemblies while minimizing the problems found in prior art designs.

SUMMARY

In accordance with this disclosure, novel apparatuses, systems and methods are provided for fluid straining for use in a fluid piping system. In one aspect, a fluid strainer is provided. The fluid strainer can comprise a housing comprising a first valve chamber comprising an inlet port, a first port, and a second port, and a second valve chamber comprising a third port, a fourth port, and an outlet port. A first strainer chamber can comprise a first strainer inlet in communication with the first port and a first strainer outlet in communication with the third port, and a second strainer chamber can comprise a second strainer inlet in communication with the second port and a second strainer outlet in communication with the fourth port. Within the first valve chamber, a first seal assembly can comprise a first pivotable member, a first disk, and a first coupler connecting the first pivotable member to the first disk such that the first pivotable member is movable to cause the first disk to move within the first valve chamber into sealing engagement against either of the first port or the second port. Similarly, within the second valve chamber, a second seal assembly can comprise a second pivotable member, a second disk, and a second coupler connecting the second pivotable member to the second disk such that the second pivotable member is movable to cause the second disk to move within the second valve chamber into, sealing engagement against either of the third port or the fourth port.

Although an aspect of the subject matter disclosed herein has been stated hereinabove, and which is achieved in whole or in part by the presently disclosed subject matter, other aspects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.

DETAILED DESCRIPTION

The present subject matter provides devices for fluid straining for use in a fluid piping system. In one aspect, the present subject matter provides a fluid strainer, generally designated100. As shown inFIGS. 1 and 2, fluid strainer100can comprise a housing110, which can itself comprise a first valve chamber112defining a strainer inlet114and a second valve chamber116defining a strainer outlet118. Fluid strainer100can be installed in-line with a fluid piping system such that fluid is received from an upstream piping element at strainer inlet114and passed to a downstream piping element out of strainer outlet118.

In addition, strainer100can further include a first strainer chamber210and a second strainer chamber220, each in communication with both of first valve chamber112and second valve chamber116, and each containing a removable strainer basket or filter therein for straining and cleaning the material which flows therethrough. Each of housing110, first strainer chamber210, and second strainer chamber220can be composed of a cast iron material, stainless steel, bronze, or any other material determined to be appropriate for the particular fluid piping system. First strainer chamber210and second strainer chamber220can each be secured to housing110using any of a variety of fasteners, including but not limited to studs, bolts, or clamps. One or both of first strainer chamber210or second strainer chamber220can be detachable from housing110, which can allow easy access for cleaning, repair, or any other maintenance procedure.

In this configuration, fluid received by first valve chamber112through strainer inlet114can be passed to either or both of first strainer chamber210or second strainer chamber220, entrained solids or other undesirable materials can be removed from the fluid within first or second strainer chambers210or220, the fluid can be passed from the strainer chambers to second valve chamber116, and the fluid can be discharged from second valve chamber116through strainer outlet118.

In particular, in addition to strainer inlet114, first valve chamber112can further define a first port121and a second port122. In the configuration shown inFIG. 1, for example, first port121and second port122can be positioned on opposite sides of first valve chamber112. Each of first port121and second port122can serve as fluid pathways out of first valve chamber112(e.g., toward first strainer chamber210or second strainer chamber220, respectively). For instance, first strainer chamber210can comprise a first strainer inlet212in communication with first port121, whereas second strainer chamber220can comprise a second strainer inlet222in communication with second port122. In this arrangement, fluid received by first valve chamber112through strainer inlet114can be directed through either or both of first port121or second port122for directing fluid to one or both of first or second strainer chambers210or220, respectively.

Likewise, second valve chamber116can define a third port123and a fourth port124, which can be positioned on opposing sides of second valve chamber116and can each serve to admit fluid into second valve chamber116(e.g., from first strainer chamber210or second strainer chamber220, respectively). For instance, first strainer chamber210can comprise a first strainer outlet214in communication with third port123, and second strainer chamber220can comprise a second strainer outlet224in communication with fourth port124. In this arrangement, fluid from either or both of first or second strainer chambers210or220can be directed to second valve chamber116through third and fourth ports123or124, respectively, for directing fluid to second valve chamber116and out of fluid strainer100through strainer outlet118.

Regarding the particular design of fluid strainer100,FIG. 1shows a cutaway front view of fluid strainer100. As shown inFIG. 1, fluid strainer100can comprise a movable flow control system within housing110to selectively control the flow of fluid to either or both of first or second strainer chambers210or220. Specifically, for example, the flow control system can comprise a first disk130movable within first valve chamber112into sealing engagement against either of first port121or second port122. First disk130can be sufficiently sized so that it is capable of closing off flow when moved against either of first port121or second port122. In this regard, first disk130can include sealing elements, such as O-rings formed from an elastomeric material (e.g., rubber), which can help first disk130to form a fluid-tight seal with first port121or second port122.

To help guide the movement of first disk130within first valve chamber112, first disk130can be connected to a first disk stem132that extends away from one side of first disk130towards first port121. First disk stem132can be received by a first disk guide134positioned within first port121. Similarly, first disk130can be further connected to a second disk stem136that extends away from the other side of first disk130towards second port122. Second disk stem136can be received by a second disk guide138positioned within second port122. In this arrangement, first disk130can be slideably supported for reciprocal lateral movement in first valve chamber112.

Similarly, a second disk140can be movable within second valve chamber116into sealing engagement against either of third port123or fourth port124. Again, second disk140can be sized to substantially block flow to either of third port123or fourth port124, and second disk140can further include sealing elements (e.g., O-rings) for helping to establish a fluid-tight seal. Second disk140can be connected to a third disk stem142and a fourth disk stem146extending away from opposing sides of second disk140towards a third disk guide144positioned in third port123and a fourth disk guide148positioned in fourth port124, respectively. In this arrangement, second disk140can be slideably supported for reciprocal lateral movement in second valve chamber116.

Movement of first disk130and second disk140can be controlled by a single pivotable coupling rod150that can, for example and without limitation, extend through both of first valve chamber112and second valve chamber116. Specifically, within first valve chamber112, at least one first coupler can be mounted to coupling rod150and can extend toward first disk130. In the configuration shown inFIGS. 1, 2, 3A, and 3B, for example, the at least one first coupler can comprise a top first coupler152aand a bottom first coupler152b, which can each comprise a Scotch yoke extending from coupling rod150towards an exterior edge of first disk130. Referring toFIG. 2, top first coupler152acan extend from coupling rod150towards a first pin154aconnected at a top edge of first disk130, and bottom first coupler152bcan extend from coupling rod150towards a second pin154bconnected at a bottom edge of first disk130. Each of top first coupler152aand bottom first coupler152bcan define a substantially forked end that is adapted to capture first pin154aand second pin154b, respectively.

Likewise, within second valve chamber116, at least one second coupler can be mounted to coupling rod150and can extend toward second disk140. For example, the at least one second coupler can comprise a top second coupler156aand a bottom first coupler156b, which can each comprise a Scotch yoke extending from coupling rod150towards second disk140. Specifically, top second coupler156acan extend towards a third pin158aconnected at a top edge of second disk140, and bottom second coupler156bcan extend from coupling rod150towards a fourth pin158bconnected at a bottom edge of second disk140.

In this arrangement, when coupling rod150is rotated, the rotation can be transferred by first couplers152aand152band second couplers156aand156binto linear sliding displacement of both first disk130and second disk140. For example, coupling rod150can be rotated to a first sealing position in which first disk130is moved into sealing engagement against first port121of first strainer chamber112, and second disk140is moved into sealing engagement against third port123of second strainer chamber116. This arrangement is shown generally inFIG. 3A. As shown inFIG. 3A, in this first sealing position, fluid entering first valve chamber112through strainer inlet114can be routed through second port122into second strainer chamber220, from which it can be further routed through fourth port124into second valve chamber116, where it can be discharged from strainer outlet118. Similarly,FIG. 3Bshows first disk130moving towards this position in a version of fluid strainer100having two strainer baskets in each of first strainer chamber210and second strainer chamber220. Regardless of the specific configuration of fluid strainer100, however, the movement of first disk130and second disk140can be substantially the same.

Alternatively, coupling rod150can be rotated to move to a second sealing position in which first disk130is in sealing engagement against second port122at the same time that second disk140is in sealing engagement against fourth port124. In this arrangement, fluid entering first valve chamber112through strainer inlet114can be routed through first port121, first strainer chamber210, and third port123into second valve chamber116, where it can be discharged from strainer outlet118.

Finally, a number of additional features can further improve the operation of fluid strainer100. First, a pressure equalization line generally designated160can be connected between first strainer chamber210and second strainer chamber220for improving service life of seals within fluid strainer100and minimizing operating torque. Specifically, for instance, when coupling rod150is moved to the first sealing position (i.e., positioned for flow through second strainer chamber220), fluid pressure in the system can tend to maintain first disk130and second disk140against first port121and third port123, respectively, making it difficult to move coupling rod150to the first sealing position or to a neutral position in between the first and second sealing positions. To alleviate this problem, pressure equalization line160can be operated to reduce or eliminate the pressure differential between the active fluid pathway (e.g., first valve chamber112, second strainer chamber220, and second valve chamber116) and first strainer chamber210, thereby requiring less force to operate coupling rod150.

Another feature that can be advantageously included in fluid strainer100is a flow-smoothing mechanism to reduce turbulence within the fluid pathways of fluid strainer100. Specifically, fluid strainer100can comprise a plurality of flow routing vanes at least partially traversing one or more of first port121, second port122, third port123, or fourth port124. For example, referring again toFIG. 1, first port121can comprise a plurality of first flow routing vanes171positioned across the opening. First flow routing vanes171can be configured to alter incoming turbulent flow between first valve chamber112and first strainer chamber210to become smoother, thereby reducing pressure drop, noise, erosion, corrosion, vibration, and/or cavitations. Similarly, as shown inFIG. 1, one or more of second port122, third port123, and/or fourth port124can likewise comprise a plurality of second flow routing vanes172, third flow routing vanes173, and/or fourth flow routing vanes174, respectively, for smoothing the flow through those ports.

The present subject matter can be embodied in other forms without departure from the spirit and essential characteristics thereof. The embodiments described therefore are to be considered in all respects as illustrative and not restrictive. Although the present subject matter has been described in terms of certain preferred embodiments, other embodiments that are apparent to those of ordinary skill in the art are also within the scope of the present subject matter.