NZ207695A - Serial butterfly valves with interpassage drain valve - Google Patents

Description

207695 PATENTS FORM NO: 5 THE PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No: 207695 Dated; 30th March 1984 TITLE: "VALVE ASSEMBLY" We, THE DEVELOPMENT FINANCE CORPORATION OF NEW ZEALAND, a body corporate carrying on under Development Finance Corporation Act 1973 having it's Head Office at DFC Centre, Corner Grey and Featherston Streets, Wellington and a Branch Office at National Mutual Centre, 312-314 Victoria Street, Hamilton, New Zealand 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: 207695 This invention relates to valve assemblies.

In an industry such as the dairy industry it is common to have a situation where a conduit used to convey a product must be cleaned on a regular basis and in such arrangements it is common to have the conduit directly communicable with a cleaning source.

In the instance of the dairy industry, Regulations state that, in a situation as above, two "shut-off" valves must be interposed by a run off drain.

•It is an object of the present invention to provide a valve assembly which will meet the above requirements.

Further objects and advantages of the present invention will become apparent from the ensuing description which is given by way of example.

According to the broadest aspect of the present invention, there is provided a valve assembly comprising a housing defining a passage, two valve members mounted in a longitudinal spaced relationship in the housing, said valve members being adapted to close off the passage, and outlet means disposed within the passage and between the valve means, said outlet means providing outlet from the interiors of the passage between the valve members.

According to a further aspect of the present invention, the valve members are butterfly valves.

According to yet a further aspect of the present invention the housing is formed from a single piece of material such as stainless steel or tubestock.

Aspects of the present invention will now be described with reference to the accompanying drawings in which: 207695 Figure 1: is a cross-section on the longitudinal axis of a valve assembly in accordance with one possible embodiment of the present invention, and Figure 2: is a cross-section at X:X of Figure 1.

With respect to the drawings, a valve assembly in accordance with the example illustrated is indicated by arrow 1 and comprises a housing generally indicated by arrow 2, providing a passage 3 therein, and two valve members generally indicated by arrow 4 mounted in a longitudinal spaced relationship in the housing 2, said valves 4 being adapted to close off the passage 3, and outlet means generally indicated by arrow 5 disposed within the passage 3 and between the valve members 4, said outlet means 5 providing an outlet from the interiors of the passage 3 between the valve members 4.

The valve member valves are butterfly valves comprising a disc member 6 rotatable from "on" to "off" positions mounted with respect to the housing 2 on co-axialshafts 7 and with respect to an accommodating bearing generally indicated by arrow 8. The bearing 8 comprises a bearing housing 9 fixed to or integrally formed with the housing 2 and a plain bearing 10. The bearing 8 also includes an inner groove 11 which accommodates sealing means such as rubber sealing washer 12 in a complementary manner. One of the shafts 7 is provided with an extending portion 13 which is adapted to mount a turning member (not shown) by which the valves can be turned from the "on" to "off" positions. The ends of the housing 2 are adapted for receiving a pipe coupling (not shown).

The housing 2 is formed from a single piece of pipe or tubestock and for uses within the dairy industry, the tubestock may be in stainless steel.

The outlet means 5 may be plain (not shown) or as illustrated is provided with a shut off mechanism generally indicated by arrow 15 mounted within an outlet housing 16 also fabricated or moulded from tube stock. 207695 In the example illustrated, the shut off mechanism comprises a valve member generally indicated by arrow 17 comprising a stem 18 and a valve head 19 with a tapered lower surface 20 complementary with a valve seat 21. The valve head 19 is provided with an "O" ring sealing member 19A as illustrated.

The outlet pipe 16 defines two interior chambers 23 and 24 and is closed off by a sealed cap 25.

A fluid mainstream outlet 26 is provided from the interior chamber 23. The part of the valve stem 18 within the interior chamber 24 is mounted with a substantially T-section piston member 27 and sockets 28 and apertures 29 are provided communicable with the interiors of the interior chamber 24. The valve member 7 is normally biased to a closed position and to give affect to this coil a spring 30 is mounted in the interior chamber 24 between the upper external surfaces 24 of the piston member 27 and the interior surfaces of the outlet pipe 16.

A sealing "O" ring 31 is provided at the opening 32 between the interior chambers 23 and 24 and a similar "O" ring sealing means 33 may be provided between the outlet piston surfaces and the interiors of the inner chamber 24.

The piston member 27 is releasably attached to the valve stem 18 as may be the cap 25 with respect to the outlet pipe 16.

The interior chamber 23 includes a valve stem guide 34 substantially as illustrated.

The application of unequal fluid pressures of the interior chambers 24 on either side of the piston member 27 will cause and/or assist the movement of the valve member 17 to open and close positions. In the dairy industry such a source of fluid differential is readily available in the form of compressed high or low pressure air.

It is to be appreciated however, that the valve member 17 may be mounted with respect to (for example) a threaded opening 32 so that it may be manually operated 207695 to open or closed positions or that other mechanisms may be used for the same purpose.

Because the valve members 4 are relatively close together it will be appreciated that mechanisms (not shown) may be included to turn the valve members from "on" to "off" positions or visa versa in unison, and where applicable the same movement may be arranged to open or close the valve member 17.

The valve assembly of the present invention is both compact and convenient to install.

Aspects of the present invention have been described by way of example only and it will be appreciated that modifications and additions thereto may be made without departing from the scope thereof, as defined in the appended claims. 207695

Claims (4)

WHAT WE CLAIM IS:

1. A valve assembly comprising a housing defining a passage, two valve members mounted in a longitudinal spaced relationship in the housing, said valve members being adapted to close off the passage and outlet means disposed within the passage between the valve members said outlet means providing an outlet from the interiors of the passage between the valve members wherein each of the valve members is a butterfly valve and the outlet means includes a shut-off valve normally biased closed but controllable to open to allow fluid to flow from the outlet.

2. A valve assembly as claimed in claim 1 wherein the outlet means comprises a valve housing fixed to the housing defining the passage, said valve housing mounting the shut-off valve therefor which is normally biased against a valve seat to close off the outlet, said shut-off valve including a valve head cooperative with the valve seat and a valve stem which extends into a pressure chamber defined by the housing, a piston mounted on the portion of the valve stem which extends into the pressure chamber and apertures in the wall of the valve housing communicable with the interiors of the pressure chamber to either side of the piston the arrangement and construction being such that the application of differential pressure to the interiors of the pressure chamber via the apertures can be used to control the position of said shut-off valve.

3. A valve assembly as claimed in claim 2 wherein the shut-off valve is normally biased to a closed position by a spring positioned between the piston and an adjacent face of the pressure chamber.

4. A valve assembly as claimed in claims 2 or 3 wherein the shut-off valve housing defines an outlet chamber for fluids which is separate from said pressure chamber. -6- 207695 A valve assembly substantially as herein described with reference to the accompanying drawings. THE DEVELOPMENT FINANCE CORPORATION OF NEW ZEALAND By their Attorneys