Bonded seat with annular ribs

A bonded seat for a butterfly valve can comprise a first axial end and a second axial end distal from the first axial end; a central section between the first axial end and the second axial end, the central section defining a radially inward surface and a radially outward surface, the radially inward surface defining a fluid bore therethrough from the first axial end to the second axial end, the radially outward surface defining a plurality of annular ribs.

TECHNICAL FIELD

This disclosure relates to fluid valves. More specifically, this disclosure relates to butterfly valves with bonded rubber seats.

BACKGROUND

A fluid valve can comprise a valve body and a seat positioned within the valve body. In some valves, a valve disc is positioned within the seat in a fluid bore defined through the seat and defines a seal with the seat. The valve disc can be moved about and between a closed position blocking a fluid path through the fluid bore and an open position opening the fluid path through the fluid bore. In the closed position, the valve disc forms a seal with the seat. Butterfly valves are valves with a rotatable valve disc positioned in the fluid bore and with a stem attached to the valve that can be turned to rotate the valve disc. Bonded seat valves are valves in which the seat is molded over an inner surface of the valve body. In bonded seat butterfly valves, portions of the seat around the stem can be unintentionally shifted relative to the valve body when the disc is rotated, reducing the tightness of the seal between the seat and the valve disc. Shifting of portions of the seat can also occur when the valve is pressurized with fluid pressure pressing on one side of the valve disc, pushing the valve disc slightly downstream and thereby pushing against the seat at edges of the valve disc. The portions of the seat around the stem are typically smooth, making shifting of the seat easier and therefore more prone to seal failure.

SUMMARY

Disclosed is a bonded seat for a butterfly valve comprising a first axial end and a second axial end distal from the first axial end; a central section between the first axial end and the second axial end, the central section defining a radially inward surface and a radially outward surface, the radially inward surface defining a fluid bore therethrough from the first axial end to the second axial end, the radially outward surface defining a plurality of annular ribs.

Also disclosed is a bonded seat valve comprising a valve body comprising a first axial end, a second axial end, and a central section, the first axial end distal from the second axial end, the central section between the first axial end and the second axial end, the central section defining a radially inward surface and a radially outward surface, the radially inward surface defining a seat bore therethrough from the first axial end to the second axial end, the radially inward surface defining a plurality of annular grooves; a seat positioned in the seat bore and bonded to the radially inward surface of the central section of the valve body, the seat including a first axial end, a second axial end, and a central section, the first axial end distal from the second axial end, the central section between the first axial end and the second axial end, the central section defining a radially inward surface and a radially outward surface, the radially inward surface defining a fluid bore therethrough from the first axial end to the second axial end, the radially outward surface defining a plurality of annular ribs extending into the plurality of annular grooves; and a valve disc positioned in the fluid bore of the seat and configured to move about and between a closed position and an open position, wherein the valve disc in the closed position blocks a flow path from the first axial end of the seat to the second axial end of the seat, and wherein the valve disc in the open position opens the flow path from the first axial end of the seat to the second axial end of the seat.

Also disclosed is a method of manufacturing a bonded seat valve, the method comprising forming a valve body including a first axial end, a second axial end, and a central section, the first axial end distal from the second axial end, the central section between the first axial end and the second axial end, the central section defining a radially inward surface and a radially outward surface, the radially inward surface defining a seat bore therethrough from the first axial end to the second axial end, the radially inward surface defining a plurality of annular grooves; molding a seat over the radially inward surface in the seat bore of the valve body, the seat including a first axial end, a second axial end, and a central section, the first axial end distal from the second axial end, the central section between the first axial end and the second axial end, the central section defining a radially inward surface and a radially outward surface, the radially inward surface defining a fluid bore therethrough from the first axial end to the second axial end, the radially outward surface defining a plurality of annular ribs extending into the plurality of annular grooves; and positioning a valve disc in the fluid bore of the seat.

DETAILED DESCRIPTION

The following description is provided as an enabling teaching of the present devices, systems, and/or methods in their best, currently known aspect. To this end, those skilled in the relevant art will recognize and appreciate that many changes can be made to the various aspects described herein, while still obtaining the beneficial results of the present disclosure. It will also be apparent that some of the desired benefits of the present disclosure can be obtained by selecting some of the features of the present disclosure without utilizing other features. Accordingly, those who work in the art will recognize that many modifications and adaptations to the present disclosure are possible and can even be desirable in certain circumstances and are a part of the present disclosure. Thus, the following description is provided as illustrative of the principles of the present disclosure and not in limitation thereof.

As used throughout, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a quantity of one of a particular element can comprise two or more such elements unless the context indicates otherwise.

The word “or” as used herein means any one member of a particular list and also comprises any combination of members of that list.

To simplify the description of various elements of the valve disclosed herein, the conventions of “top,” “bottom,” “inner,” “outer,” “inside,” or “outside,” may be referenced. Unless stated otherwise here or in the figures, “top” describes that side or end of the valve that is facing upward as shown in the figures and “bottom” is that side or end of the valve that is opposite or distal the top of the valve and is facing downward as shown in the figures. Likewise, “outer” describes that side of the valve that is facing outward and “inner” is that side of the valve that is facing inward.

Disclosed is a bonded seat and associated methods, systems, devices, and various apparatus. The bonded seat can comprise a first axial end, a second axial end, and a central section. It would be understood by one of skill in the art that the disclosed bonded seat is described in but a few exemplary aspects among many. No particular terminology or description should be considered limiting on the disclosure or the scope of any claims issuing therefrom.

One aspect of a bonded seat valve100is shown inFIG. 1. The bonded seat valve100can comprise a valve body110, a seat120, a valve disc130, and a stem140. The bonded seat valve100can define an axis102extending through the bonded seat valve100, and can comprise an inlet104and an outlet204(shown inFIG. 2). The valve body110can comprise a first axial end112and a second axial end114relative to the axis102, and the seat120can define a first axial end122and a second axial end124(shown inFIG. 2) relative to the axis102. The valve body110can also comprise a central section116between first axial end112and the second axial end114. Likewise, the seat120can also comprise a central section126between first axial end122and the second axial end124.

The valve body110can comprise a first mounting flange152at the first axial end112and a second mounting flange154at the second axial end114. The first mounting flange152and the second mounting flange154can each define a plurality of mounting bores156,158, respectively, and can each be configured for attachment to complementary mounting flanges on pipe elements such as flanged pipes or pipe fittings or for attachment to restraint devices such as mechanical joint restraints that are, for example, configured to attach the bonded seat valve assembly100to pipe elements such as plain-end pipes. The mounting bores156,158can thus be configured for use with fasteners such as nuts and bolts to attach the mounting flanges152,154to other mounting flanges or restraint devices. The valve assembly100can thereby be mounted in pipe systems such as municipal water systems.

The valve body110can also comprise a top trunnion160and a bottom trunnion162. The top trunnion160can comprise a mounting flange164and can define an upper stem bore166therethrough. The stem140can extend through the upper stem bore166to the valve disc130and a stem packing168can surround the stem140in the upper stem bore166proximate to the mounting flange164. The stem140can define a stem axis142therethrough that can intersect the axis102at a perpendicular angle. An actuator (not shown) can be attached to the stem140and the mounting flange164to rotate the stem140and the valve disc130about the stem axis142. In various aspects, the actuator can be any desired configuration, such as a mechanical, electrical, or hydraulic actuator, including but not limited to a nut, a handle, a handwheel, a chainwheel, an electric motor, or a hydraulic or pneumatic cylinder.

As shown inFIG. 2, the valve disc130can be positioned within the seat120and the stem140can extend through the valve disc130. Angles210show how the valve disc130can be rotated about the stem axis142into and out of sealing engagement with the seat120. The valve disc130is shown in a closed position with the valve disc130in sealing engagement with the seat120, and rotating the valve disc130on the stem axis142towards and past angles210moves the valve disc130to an open position that opens a flow path from the first axial end122to the second axial end124, allowing fluid to flow from the inlet104to the outlet204.

The central section126of the seat120can define a radially inward surface220and a radially outward surface226. The radially inward surface220can define fluid bore228therethrough from the first axial end122to the second axial end124. An outer edge232of the valve disc130can seal against the radially inward surface220of the seat120in the closed position, blocking the fluid path through the fluid bore228from the first axial end122to the second axial end124and compressing a portion of the seat120that the outer edge232engages against. The seat120can also define a first flange222defined at the first axial end122and a second flange224defined at the second axial end124. The flanges222,224can extend radially outward relative to the axis102. The first flange222can be positioned in a first flange cutout212defined in the first axial end112of the valve body110and the second flange224can be positioned in a second flange cutout214defined in the second axial end114of the valve body110. The first axial end112of the valve body110can therefore be coplanar with the first axial end122of the seat120, and the second axial end114of the valve body110can likewise be coplanar with the second axial end124of the seat120.

The central section116of the valve body110can define a radially inward surface218and a radially outward surface216. The radially inward surface218can define a seat bore710(shown inFIG. 7) therethrough extending from the first axial end112to the second axial end114. The radially outward surface226of the central section126of the seat120can be bonded to the radially inward surface218of the central section116of the valve body110. In various aspects, the seat120can be bonded to the valve body110by molding the seat120over the radially inward surface218of the valve body110. In particular, the seat120can be molded by molding rubber, such as EPDM rubber or Buna-N rubber, in a mold covering the radially inward surface218of the valve body110, which itself can be formed from cast iron in some aspects. The valve body110can be cast from cast iron by casting the valve body110in a mold, such as a sand mold. When the valve body110is formed from cast iron and the seat120is formed from molded rubber, the rubber flows into and solidifies within imperfections defined in the radially inward surface218formed in the casting process of forming the valve body110, and the seat120is thereby bonded to the valve body110.

The radially outward surface226of the seat120can comprise a plurality of annular ribs250extending radially outward from the central section126, and the radially inward surface218of the valve body110can comprise a plurality of annular grooves260. The plurality of annular ribs250can extend into the plurality of annular grooves260. When the valve disc130rotates towards the closed position, closing the angle210, the outer edge232of the valve disc130compresses the seat120into the plurality of grooves260, thereby preventing any portions of the seat120from shifting relative to the valve body110. The ribs250and grooves260thereby act to ensure tightness of the seal between the valve disc130and the seat120when the valve disc130is in the closed position.

As shown inFIG. 3, the stem140can extend entirely through the valve disc130from the top trunnion160to the bottom trunnion162. The valve assembly100can further comprise a bottom cap360attached to the bottom trunnion162by fasteners362and covering a lower stem bore366through the bottom trunnion162. A pin330can attach the stem140to the valve disc130. In other aspects, the stem140can only extend through the upper stem bore166and a second stem (not shown) can extend through the lower stem bore366, both stems attaching to the valve disc130at opposite ends of the valve disc130. In other aspects, the stem140only extends through the upper stem bore166to attach to an upper end of the valve disc130and no other stem extends through the valve body110.

As shown inFIG. 4, the seat120can define an upper stem bore426and a lower stem bore428. The seat120can comprise an upper stem flange422defining the upper stem bore426therethrough and a lower stem flange424defining the lower stem bore428therethrough. The upper stem flange422and the lower stem flange424can each act to seal against the stem140to prevent leakage between the stem140and the valve body110. The inner surface220can also define an upper bearing surface432(shown inFIG. 3) and a lower bearing surface434. In the current aspect, the upper bearing surface432and the lower bearing surface434can each be generally flat such that the valve disc130can rotate on each bearing surface432,434when moving between the open position and the closed position. The bearing surfaces432,434can also define a plurality of annular ribs436surrounding the stem bores426,428. The bearing surfaces432,434and the plurality of annular ribs436can thereby further seal against the valve disc130to prevent leakage through the stem bores426,428.

In the current aspect, there are five annular ribs250defined on the radially outward surface226. Three annular ribs250can intersect both the upper stem bore426and the lower stem bore428, terminating at the upper stem flange422and the lower stem flange424but otherwise remaining continuous between the upper stem bore426and the lower stem bore428. Two annular ribs250can extend completely and continuously around the seat120on the radially outward surface226, with one annular rib250defined between the stem bores426,428and the first axial end122relative to the axis102(shown inFIG. 1) and another annular rib250defined between the stem bores426,428and the second axial end124relative to the axis102. However, in other aspects, any other number of annular ribs250can intersect the stem bores426,428and be defined between the stem bores426,428and either of the axial ends122,124.

The radially outward surface226can also define a pair of shoulders412,414between the annular ribs250and the first and second axial ends122,124, respectively. The first shoulder412can be defined between the annular ribs250and the first axial end122, and the second shoulder414can be defined between the annular ribs250and the second axial end124. The radially outward surface226can also thereby define a radially inner cylindrical section452and a radially outer cylindrical section454on either side of the first shoulder412, and a radially inner cylindrical section456and a radially outer cylindrical section458on either side of the second shoulder414. The radially inner cylindrical section452can extend from the first shoulder412to the annular ribs250and the radially outer cylindrical section454can extend from the first shoulder412to the first flange222. Likewise, the radially inner cylindrical section456can extend from the second shoulder414to the annular ribs250and the radially outer cylindrical section458can extend from the second shoulder414to the second flange224. The shoulders412,414can similarly act to prevent portions of the seat120from shifting relative to the valve body110when the valve disc130rotates or when fluid pressure is applied to one side of the valve disc130.

FIG. 5shows a cross-section of the plurality of annular ribs250. As shown, in some aspects, the annular ribs250can define V-shaped cross-sections in which each side of each annular rib250defines a frustoconical shape. Additionally, as shown, the annular ribs250can extend a further distance in a radial direction relative to the axis102(shown inFIG. 1) from the inner cylindrical sections452,456than the shoulders412,414.FIG. 6shows another aspect of the plurality of annular ribs250in which the annular ribs250can define arcuate cross-sections. Additionally, the plurality of annular ribs250can each define a cylindrical transition section650therebetween to space the annular ribs250apart from each other. The radially outward surface226can also define an additional pair of shoulders612,614proximate to each side of the plurality of annular ribs250to serve as transitions from the annular ribs250to the radially inner cylindrical sections452,456.

FIG. 7shows the valve body110prior to molding the seat120to the valve body110. As shown, five of the annular grooves260can be defined in the radially inward surface218. Three annular grooves260can intersect both the upper stem bore166and the lower stem bore366but otherwise remain continuous between the upper stem bore166and the lower stem bore366. Two annular grooves260can extend completely and continuously around the valve body110on the radially inward surface218, with one annular groove260defined between the stem bores166,366and the first axial end112relative to the axis102(shown inFIG. 1) and another annular groove260defined between the stem bores166,366and the second axial end114relative to the axis102. However, in other aspects, any other number of annular grooves260can intersect the stem bores166,366and be defined between the stem bores166,366and either of the axial ends112,114.

The annular ribs250and annular grooves260thus control deformation and displacement of portions of the seat120proximate to the valve disc130. The seal between the valve disc130and the seat120in the closed position is thus increased, reducing leak possibilities and increasing the pressure rating of the bonded seat valve100.