GB1592733A

GB1592733A - Pipeline valves

Info

Publication number: GB1592733A
Application number: GB1098980A
Authority: GB
Original assignee: Otto Tuchenhagen GmbH and Co KG
Current assignee: Otto Tuchenhagen GmbH and Co KG
Priority date: 1977-11-14
Filing date: 1978-01-26
Publication date: 1981-07-08
Also published as: CA1077912A; DE2750833C2; DE2750833A1; SU1233812A3

Description

(54) IMPROVEMENTS IN OR RELATING TO PIPELINE VALVES (71) We, OTTO TUCHENHAGEN GMBH & CO. KG, (formerly Otto Tuchenhagen) a Germany Company, of Berliner Strasse 4, 2059 Büchen, Federal Republic of Germany, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to doubleseat pipeline valves, for example, for use in the foodstuffs industry.

A double-seat pipeline valve is described in German Auslegeschrift No. 2632587 and comprises two valve discs which are movable relative to one another, the lower of the two valve discs being rigidly connected to drive means by a valve rod. Movement of the lower valve disc is arranged to bring the lower valve disc is arranged to bring the lower valve disc into contact with the upper valve disc such that further movement of the lower valve disc also moves the upper valve disc. The two valve discs define a leakage cavity between them and this is communicated with the environment of the valve by the bore of a pipe which forms an extension of the valve rod and extends away from the drive means. The upper valve disc is carried on a hollow rod which concentrically surrounds the valve rod.The end of the hollow rod remote from the upper valve disc carries a connector which accommodates a connection opening for cleaning fluids, an abutment for a biasing spring and a stop surface for stroke limitation.

It is an object of the present invention to provide a double-seat pipeline valve in which the spring is included in the cleaning process for the leakage cavity.

According to the present invention there is provided a double-seat pipeline valve comprising two valve discs disposed within a valve housing having an inlet and an outlet, the valve discs being movable relative to one another and each being movable relative to a respective valve seat to open and close the valve, wherein one of the valve discs is smaller than the other, the smaller valve disc being rigidly connected to drive means by way of a valve rod for movement with respect to its respective valve seat, the movement of said smaller valve disc being arranged to move the other, larger valve disc with respect to its respective valve seat, said larger valve disc being connected to a hollow rod which surrounds said valve rod and defines an annular gap therebetween, wherein both in the closed position and the open position of the pipeline valve the valve discs define between them a leakage cavity which is communicated by way of openings to an outlet bore which leads to the environment of the valve and is disposed within a pipe forming an extension of the valve rod and extending away from the drive means, and wherein the end of the hollow rod remote from the valve housing positively receives a pressure and guide part and the valve rod carries a housing part which together with said pressure and guide part defines a spring chamber in which a spring for urging said larger valve disc to its closed position is received, said pressure and guide part having a lower abutment surface for said spring and said housing part having an upper abutment surface for said spring, and said housing part having a connection opening for cleaning fluids which is in communication with said spring chamber, said spring chamber and said annular gap forming a connecting path communicating said leakage cavity to said connection opening.

In an embodiment, the spring chamber is annular and the connection opening extends tangentially into the chamber. In this way, optimum flow conditions are provided for the cleaning fluid. Preferably, the annular spring chamber is defined by a projection of the housing part which extends within the spring chamber and around which the spring is mounted. The projection is preferably sufficiently long that its free end forms an upper stop surface for limiting the stroke of the hollow rod.

In another embodiment the pitch of the spring is so selected that the direction vectors of the horizontal component of the spring pitch and the connection opening axis directed tangentially from outside to inside are identical. This arrangement has the effect that the turns of the spring transport cleaning liquid to a limited extent into the uppermost region of the spring chamber opposite to the connection opening so that this critical region of the chamber is effectively cleaned.

If it is difficult or inadvisable for the pressure and guide part and the housing part to be made of materials which possess adequate relative sliding properties, a sliding and guide part may be embedded in a bearing groove of the pressure and guide part to enable the pressure and guide part to slide relative to the housing part.

In an embodiment the pressure and guide part has a receiving bore which is pushed onto the holow rod to positively connect the pressure and guide part and the hollow rod.

This connection is simple to manufacture and provides the advantage that the pipeline valve is easy to assemble and dismantle.

In an embodiment, and elastic deflector is disposed at the end of the annular gap leading into the leakage cavity. This elastic deflector is provided with a sealing lip movable with respect to a sealing seat formed on the larger valve disc. The elastic deflector performs the following functions when cleaning fluids are fed to the leakage cavity through the annular gap: sealing of the annular gap against the penetration of leakage medium; admission of cleaning fluids into the leakage cavity against a resistance such that the annular gap is completely filled and flushed out; guiding of the incoming cleaning fluid by the sealing lip of the deflector, which lip when lifted off its sealing seat on the top valve disc forms a gap in the form of an annular nozzle, onto the inner surfaces of the leakage cavity which are to be cleaned.

An embodiment of the present invention will hereinafter be described, by way of example, with reference to the accompanying drawing, in which the single Figure shows a cross-section through a pipeline valve according to the invention.

The double-seat pipeline valve shown in the Figure comprises a valve housing 31 having parts 32 and 33. The valve housing 31 contains a smaller valve disc 34 and a larger valve disc 35. The smaller valve disc 34 is independently driven and rests on a smaller valve seat 31a. The smaller valve disc 34 is carried on a valve rod 34a. The valve rod 34a has a fastening part 34i which is connected to drive means 34h, 39, 312, 313 for the pipeline valve by means of a threaded bore 34j in a drive pin 34k. The drive means is connected with a cross-member 25 and consists of a driving housing 312, a piston 34h, a working fluid connection 313 and a drive spring 39. The larger valve disc 35, which is driven in dependence on the smaller valve disc 34, lies on a larger valve seat 31b and is supported on a hollow rod 35a.The valve rod 34a is guided concentrically in the hollow rod 35a and together with the latter forms an annular gap 35d which connects a leakage cavity 38 formed by the valve discs 34 and 35 to a connection opening 315a provided in a housing part 315. A second connecting path between the environment of the pipeline valve and the leakage cavity 38 is formed by a bore 34c which is provided in a pipe 34d which is an extension of the valve rod 34a, and extends out of the pipeline valve housing 31 on the side thereof remote from the drive means 34h, 39, 312, 313. The bore 34c is in communication with the leakage cavity 38 by way of openings 34b. The larger valve disc 35 has a cylindrical extension 35g which defines a disc annular gap 311.

The valve also comprises a pressure and guide part 314 which together with the housing part 315 forms a spring chamber 315f. A spring 310, which applies a force to the hollow rod 35a both in the open position and in the closed position of the pipeline valve urging the larger valve disc 35 towards its seat 31b, is mounted within the spring chamber 315f around a projection 315b of the housing part 315. The housing part 315 also has an upper spring abutment surface 315d and, at the end of the projection 315b, an upper stop surface 315e. The housing part 315 is sealed in relation to the valve rod 34a by means of a valve rod seal 316 in a seal holder 316a. The housing part 315 is fastened on the valve rod 34a by means of a threaded bore 315c which is screwed onto the fastening part 34i of the valve rod 34a.

The pressure and guide part 314 is positively connected to the hollow rod 35a by pushing a receiving bore 314a formed in the part 314 onto the hollow rod 35a. The pressure and guide part 314 has a seat surface 314b which faces the spring 310 and forms a bottom stop surface and a lower abutment surface for the spring 310. The part 314 is guided in the housing part 315 by means of a sliding and guide part 319 embedded in a bearing groove 319a. The part 314 is sealed in relation to the housing part 315 by way of a seal 317 received in a seal holder 317a and in relation to the hollow rod 35a, by way of a seal 318 received in a seal holder 318a.

In the Figure the pipeline valve is shown in the closed position. When the pipeline valve is operated, working medium, for example compressed air, is passed through the working fluid connection 313 into the drive housing 312 to move the piston 34h.

Movement of the piston 34h lifts the smaller valve disc 34 off the smaller valve seat 31a by way of the valve rod 34a. The valve rod 34a moves relative to the hollow rod 35a and the housing part 315 moves relative to the pressure and guide part 314. During the movement of the smaller valve disc 34 valve leakage passes out of the valve housing part 33 into the leakage cavity 38 until the smaller valve disc 34 comes to bear against the larger valve disc 35 and forms a seal against the latter through the continuing action of the spring 310. As the upward movement of the piston 34h continues, the larger valve disc 35 is also lifted off the larger valve seat 31b, so that communication between the valve housing parts 32 and 33 is established.When the pipeline valve is in the open position the spring 310 also ensures that the leakage cavity 38 is closed to the medium inside the valve housing parts 32 and 33.

The pipeline valve is closed in a similar manner but in the reverse sequence to that for the opening operation described by flowing working medium out of the drive housing 10. Here again valve leakage passes from the valve housing part 33 into the leakage cavity when the larger valve disc 35 has reached the larger valve seat 31b and the smaller valve disc 34 is moving from its position in which it bears against the larger valve disc 35 to the smaller valve seat 31a.

The leakage cavity 38 can be cleaned both in the closed position and in the open position of the pipeline valve. Cleaning fluids are supplied through connection opening 315a in the housing part 315. The axis of this connection opening 315a is tangentially aligned with respect to the annular spring chamber 315f defined by the projection 31b and extends perpendicularly to the longitudinal axis of the valve rod 34a.

This construction ensures that the cleaning fluids flowing into the spring chamber 315f are imparted with a spin which improves the cleaning action of the chamber. Furthermore, the pitch of the spring 310 is so selected that the direction vectors of the horizontal component of the spring pitch and of the axis of the connection opening 315a are identical such that the turns of the spring to a limited extent transport cleaning fluid into the uppermost region of the spring chamber 315f, lying opposite to the connection opening 315a.

The cleaning fluids pass from the spring chamber 315f along the annular gap 35d into the leakage cavity 38. The bore 34c in the pipe 34d, which communicates with the leakage cavity 38 by way of the openings 34b, forms the outlet path for leakage liquid and/or for the cleaning fluids.

A double-seat pipeline valve is described and claimed in copending application No.

3211/78 (Serial No. 1592732) from which the present application is divided.

WHAT WE CLAIM IS: 1. A double-seat pipeline valve comprising two valve discs disposed within a valve housing having an inlet and an outlet, the valve discs being movable relative to a respective valve seat to open and close the valve, wherein one of the valve discs is smaller than the other, the smaller valve disc being rigidly connected to drive means by way of a valve rod for movement with respect to its respective valve seat, the movement of said smaller valve disc being arranged to move the other, larger valve disc with respect to its respective valve seat, said larger valve disc being connected to a hollow rod which surrounds said valve rod and defines an annular gap therebetween, wherein both in the closed position and the open position of the pipeline valve the valve discs define between them a leakage cavity which is communicated by way of openings to an outlet bore which leads to the environment of the valve and is disposed within a pipe forming an extension of the valve rod and extending away from the drive means, and wherein the end of the hollow rod remote from the valve housing positively receives a pressure and guide part and the valve rod carries a housing part which together with said pressure and guide defines a spring chamber in which a spring for urging said larger valve disc to its closed position is received, said pressure and guide part having a lower abutment surface for said spring and said housing part having an upper abutment surface for said spring, and said housing part having a connection opening for cleaning fluids which is in communication with said spring chamber, said spring chamber and said annular gap forming a connecting path communicating said leakage cavity to said connection opening.

2. A pipeline valve as claimed in Claim 1, wherein said housing part has a projection which extends within said spring chamber and around which the spring is mounted, the free end of the projection forming an upper stop surface for limiting the stroke of the hollow rod.

3. A pipeline valve as claimed in Claim 1 or 2, wherein the spring chamber is annular, and wherein the axis of the connection opening extends tangentially with respect to said spring chamber and perpendicularly to the longitudinal axis of said valve

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Claims

**WARNING** start of CLMS field may overlap end of DESC **.

hollow rod 35a, by way of a seal 318 received in a seal holder 318a.

In the Figure the pipeline valve is shown in the closed position. When the pipeline valve is operated, working medium, for example compressed air, is passed through the working fluid connection 313 into the drive housing 312 to move the piston 34h.

Movement of the piston 34h lifts the smaller valve disc 34 off the smaller valve seat 31a by way of the valve rod 34a. The valve rod 34a moves relative to the hollow rod 35a and the housing part 315 moves relative to the pressure and guide part 314. During the movement of the smaller valve disc 34 valve leakage passes out of the valve housing part 33 into the leakage cavity 38 until the smaller valve disc 34 comes to bear against the larger valve disc 35 and forms a seal against the latter through the continuing action of the spring 310. As the upward movement of the piston 34h continues, the larger valve disc 35 is also lifted off the larger valve seat 31b, so that communication between the valve housing parts 32 and 33 is established.When the pipeline valve is in the open position the spring 310 also ensures that the leakage cavity 38 is closed to the medium inside the valve housing parts 32 and 33.

The pipeline valve is closed in a similar manner but in the reverse sequence to that for the opening operation described by flowing working medium out of the drive housing 10. Here again valve leakage passes from the valve housing part 33 into the leakage cavity when the larger valve disc 35 has reached the larger valve seat 31b and the smaller valve disc 34 is moving from its position in which it bears against the larger valve disc 35 to the smaller valve seat 31a.

The leakage cavity 38 can be cleaned both in the closed position and in the open position of the pipeline valve. Cleaning fluids are supplied through connection opening 315a in the housing part 315. The axis of this connection opening 315a is tangentially aligned with respect to the annular spring chamber 315f defined by the projection 31b and extends perpendicularly to the longitudinal axis of the valve rod 34a.

This construction ensures that the cleaning fluids flowing into the spring chamber 315f are imparted with a spin which improves the cleaning action of the chamber. Furthermore, the pitch of the spring 310 is so selected that the direction vectors of the horizontal component of the spring pitch and of the axis of the connection opening 315a are identical such that the turns of the spring to a limited extent transport cleaning fluid into the uppermost region of the spring chamber 315f, lying opposite to the connection opening 315a.

The cleaning fluids pass from the spring chamber 315f along the annular gap 35d into the leakage cavity 38. The bore 34c in the pipe 34d, which communicates with the leakage cavity 38 by way of the openings 34b, forms the outlet path for leakage liquid and/or for the cleaning fluids.

A double-seat pipeline valve is described and claimed in copending application No.

3211/78 (Serial No. 1592732) from which the present application is divided.

WHAT WE CLAIM IS: 1. A double-seat pipeline valve comprising two valve discs disposed within a valve housing having an inlet and an outlet, the valve discs being movable relative to a respective valve seat to open and close the valve, wherein one of the valve discs is smaller than the other, the smaller valve disc being rigidly connected to drive means by way of a valve rod for movement with respect to its respective valve seat, the movement of said smaller valve disc being arranged to move the other, larger valve disc with respect to its respective valve seat, said larger valve disc being connected to a hollow rod which surrounds said valve rod and defines an annular gap therebetween, wherein both in the closed position and the open position of the pipeline valve the valve discs define between them a leakage cavity which is communicated by way of openings to an outlet bore which leads to the environment of the valve and is disposed within a pipe forming an extension of the valve rod and extending away from the drive means, and wherein the end of the hollow rod remote from the valve housing positively receives a pressure and guide part and the valve rod carries a housing part which together with said pressure and guide defines a spring chamber in which a spring for urging said larger valve disc to its closed position is received, said pressure and guide part having a lower abutment surface for said spring and said housing part having an upper abutment surface for said spring, and said housing part having a connection opening for cleaning fluids which is in communication with said spring chamber, said spring chamber and said annular gap forming a connecting path communicating said leakage cavity to said connection opening.
2. A pipeline valve as claimed in Claim 1, wherein said housing part has a projection which extends within said spring chamber and around which the spring is mounted, the free end of the projection forming an upper stop surface for limiting the stroke of the hollow rod.
3. A pipeline valve as claimed in Claim 1 or 2, wherein the spring chamber is annular, and wherein the axis of the connection opening extends tangentially with respect to said spring chamber and perpendicularly to the longitudinal axis of said valve

rod.
4. A pipeline valve as claimed in Claim 3, wherein the direction of vectors of the horizontal component of the spring pitch and of the axis of the connection opening are identical.
5. A pipeline valve as claimed in any preceding Claim, wherein a sliding and guide part is disposed in the pressure and guide part for enabling the pressure and guide part to slide relative to the housing part.
6. A pipeline valve as claimed in any preceding Claim, wherein the pressure and guide part has a receiving bore which is pushed onto the hollow rod to positively connect the pressure and guide part to the hollow rod.
7. A pipeline valve as claimed in any preceding Claim, wherein the annular gap is formed at its end leading into the leakage cavity as an annular nozzle.
8. A double-seat pipeline valve substantially as hereinbefore with reference to and as illustrated in the accompanying drawing.