GB1604095A

GB1604095A - Butterfly valve arrangements

Info

Publication number: GB1604095A
Application number: GB1411178A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-04-14
Filing date: 1978-04-14
Publication date: 1981-12-02
Also published as: DK161678A; DK156970B; FI71397B; SE7704262L; DE2815552A1; DK156970C; FI781102A; SE422703B; FI71397C

Description

(54) IMPROVEMENTS IN OR RELATING TO BUTTERFLY VALVE ARRANGEMENTS (71) 1, JORG LILLJEQVIST, of Vesslevä- gen 16, S-183 40 Täbyenstapark, Sweden, a subject of the King of Sweden, do hereby declare the invention, for which I pray that a patent may be granted to me, 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 butterfly valve arrangements.

In prior art valves, a valve member or closing member is moved in one movement to bear with its peripheral portion against a valve seat and is urged against it under heavy pressure. One of the coacting sealing surfaces may be provided with a coating portion of rubber or other yielding material.

It is known that the sealing capacity of the valve can be improved if the valve is pressed against the seat at two sealing surfaces and further if two valves are placed after each other or if the valve is provided with two valve members or closing members having each one seat.

The prior art valves have all the disadvantage that the valve does not keep tight if the seat has been damaged in some way. Another disadvantage is that in connection with closing and subsequently evacuating the system on one side of a valve it is not possible to ensure that the valve will keep tight with respect to the other side.

According to the invention, there is provided a butterfly valve arrangement comprising a housing, a movable substantially discshaped valve member, mounted on a pivotal shaft, and means for moving the valve member on the shaft between an open position and a closed position, the valve member having a sealing member with two sealing portions or two sealing members arranged to cooperate with a single seat of the housing when the valve member is in the closed position, the two sealing portions of the sealing member or the two sealing rriembers being spaced apart in the direction of flow of fluid and being arranged, when the valve member is in the closed position, to define with the single seat of the housing a closed spaced, there being provided in the single seat of the housing a closable channel communicating with the closed space so as to allow removal of any fluid which has entered the closed space to permit fluid pressure on the valve member to act on both sealing portions of the sealing member or on both sealing members.

If, in such a valve arrangement, the first sealing member or portion should be damaged, the fluid leaking through the sealing portion or member may be discharged into a drain through the discharge channel and a valve associated therewith. By opening the discharge channel, the differential pressure is eliminated between the space inside the two sealing sections of the valve member and an evacuated part of the conduit. This has the advantage that no through-leakage of any appreciable extent will occur, not even if both the sealing sections should be damaged.

It is also possible to check and ensure that the valve will remain fluid-tight when closing the valve and emptying a conduit on one side, which often is necessary in connection with repairs of conduit leaks or like defects.

Such a checking operation is carried out by closing the valve and opening the discharge channel between the sealing sections. The valve is untight if liquid runs out of the discharge valve. However, if the amount of liquid is small one may take if for granted that the valve remains fluid-tight, in spite of untight seats, as long as the discharge valve is kept open. The valve is fluid-tight if no liquid runs out of the discharge valve, even if the discharge valve is kept open.

The invention will be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a sectional view of part of an embodiment of a valve arrangement; and Fig. 2 is a sectional view of part of another embodiment.

The drawings show only such details as are essential for the explanation of the arrangement.

Referring to Fig. 1, a sealing surface 4 is provided on a valve housing 1. In this case the sealing surface consists of a ring of stainless material welded to the housing 1.

Mounted in the valve housing is a spindle 2 which supports a valve member 3, which in this case is a swivel throttle. The valve member 3 can be turned, with the aid of means not shown, into closing and open positions.

Provided on the valve member 3, which serves as closing means, are sealing sections 5 and 6 which, in the example shown, consist of parts of an integral unit formed of rubber or like material. Both the sealing sections 5 and 6 are pressed into closed position against the seating or sealing surface 4, which results in sealing cooperation between the sealing sections 5 and 6 and the seating surface 4.

In the seat 4, between the surfaces which the sealing sections 5 and 6 bear against, there is arranged at least one discharge channel 7 including a discharge valve 8.

The closing operation is in principle carried out as follows. The valve member 3 is turned by means of the spindle 2 into its closing position in which the sealing sections 5 and 6 will sealingly engage the seating surface 4 of the valve housing 1. After that the discharge valve 8 in the discharge channel 7 is opened to permit checking that the valve is tight and to obtain a lower differential pressure over the second sealing section, which improves the sealing function.

Fig. 2 illustrates another embodiment of the sealing members. In this embodiment the sealing sections 5' and 6' are two separate units spaced from each other by an intermediate part 9. For the rest the valve is shaped in analogy with the embodiment of Fig 1.

This also applies to the operating movements and the sealing cooperation of said sections.

Valves arranged according to this invention may also be combined with other sealing systems, e.g. with means for aftemtightering according to Swedish Patent 353789, or be adapted for injection of sealing liquids, grease or like substances between cooperating surfaces.

The sealing sections may also be formed with so-called lamellar sealings instead of the shown sealings S and 6 of rubber or like material.

WHAT I CLAIM IS: 1. A butterfly valve arrangement comprising a housing, a movable substantially disc-shaped valve member, mounted on a pivotal shaft, and means for moving the valve member on the shaft between an open position and a closed position, the valve member having a sealing member with two sealing portions or two sealing members arranged to cooperate with a single seat of the housing when the valve member is in the closed position, the two sealing portions of the sealing member or the two sealing members being spaced apart in the direction of flow of fluid and being arranged, when the valve member is in the closed position, to define with the single seat of the housing a closed space, there being provided in the single seat of the housing a closable channel communicating with the closed space so as to allow removal of any fluid which has entered the closed space to permit fluid pressure on the valve member to act on both sealing portions of the sealing member or on both sealing members.

2. A valve arrangement as claimed in claim 1, in which the closable channel is provided with a discharge valve at its outlet.

3. A valve arrangement as claimed in claim 1 or 2, wherein at least one of the sealing portions or members is provided with means for improving fluid-tightness with the aid of a medium which can be introduced into at least one cavity in the sealing portion or member.

4. A valve arrangement as claimed in any one of the preceding claims, wherein at least the parts of the sealing portions or members cooperating with the opposed seating surface are formed of rubber or a similar elastic material.

5. A valve arrangement as claimed in any one of claims 1 to 3, wherein the parts of the sealing portions or members cooperating with the opposed seating surface include lamella).

6. tF butterfly valve arrangement substantially as herein described with reference to and as illustrated in the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. Mounted in the valve housing is a spindle 2 which supports a valve member 3, which in this case is a swivel throttle. The valve member 3 can be turned, with the aid of means not shown, into closing and open positions. Provided on the valve member 3, which serves as closing means, are sealing sections 5 and 6 which, in the example shown, consist of parts of an integral unit formed of rubber or like material. Both the sealing sections 5 and 6 are pressed into closed position against the seating or sealing surface 4, which results in sealing cooperation between the sealing sections 5 and 6 and the seating surface 4. In the seat 4, between the surfaces which the sealing sections 5 and 6 bear against, there is arranged at least one discharge channel 7 including a discharge valve 8. The closing operation is in principle carried out as follows. The valve member 3 is turned by means of the spindle 2 into its closing position in which the sealing sections 5 and 6 will sealingly engage the seating surface 4 of the valve housing 1. After that the discharge valve 8 in the discharge channel 7 is opened to permit checking that the valve is tight and to obtain a lower differential pressure over the second sealing section, which improves the sealing function. Fig. 2 illustrates another embodiment of the sealing members. In this embodiment the sealing sections 5' and 6' are two separate units spaced from each other by an intermediate part 9. For the rest the valve is shaped in analogy with the embodiment of Fig 1. This also applies to the operating movements and the sealing cooperation of said sections. Valves arranged according to this invention may also be combined with other sealing systems, e.g. with means for aftemtightering according to Swedish Patent 353789, or be adapted for injection of sealing liquids, grease or like substances between cooperating surfaces. The sealing sections may also be formed with so-called lamellar sealings instead of the shown sealings S and 6 of rubber or like material. WHAT I CLAIM IS:

1. A butterfly valve arrangement comprising a housing, a movable substantially disc-shaped valve member, mounted on a pivotal shaft, and means for moving the valve member on the shaft between an open position and a closed position, the valve member having a sealing member with two sealing portions or two sealing members arranged to cooperate with a single seat of the housing when the valve member is in the closed position, the two sealing portions of the sealing member or the two sealing members being spaced apart in the direction of flow of fluid and being arranged, when the valve member is in the closed position, to define with the single seat of the housing a closed space, there being provided in the single seat of the housing a closable channel communicating with the closed space so as to allow removal of any fluid which has entered the closed space to permit fluid pressure on the valve member to act on both sealing portions of the sealing member or on both sealing members.