NZ234153A - Three-way electro-magnetically operated check valve - Google Patents

Description

r»• »r •* • * -• —« • C- ^ .i ..AF--"-'?®-< „ . ..t.\k?V.\v-NvO,.Ac/; XH nmrm >•>. 234 15 3 1 N.Z. HO. m ZEALAND PalOTtg Ast 19$3 COMPLETE SPECIFICATION L THREE-HAY $SATEP VAtvg HI, SULZER BROTHERS LIMITED, A Switzerland corporation, of Ch-8401, Winterthur, Switzerland, do hereby declare the invention, for which We pray that a patent way be granted to US, and the method by which 1t 1s to be performed, to be particularly described in and by the following statement ~ 1 - (Followed by 1A) 23415. 2 A three-wav seated valve Three-way seated valves are known which comprise a body having three passages extending to a chamber, communication from two passages to the chamber being controlled by two valve lids each co-operating with a valve seat, means being provided to control the movement of the lids.

The invention relates to a special construction of this kind of valve making it possible in some installations to replace two two-way valves and an automatic check valve by this single constructions.

To this end the present invention provides a three-way valve comprising: A body having a chamber therein, three flow passages extending outwardly from said chamber, a first valve seat between said chamber and one of said passages and a second valve seat between said chamber and a second of said passages; a first valve lid in said body for seating on said first valve seat to control a flow through said one passage; a second valve lid in said body for seating on said second valve seat to control a flow through said second passage; and means for controlling the movement of said valve lids, said means including a single actuating element for moving one of said lids from an open position to a closed position relative to a respective seat with the other lid being movable independently of said actuating element under the pressures prevailing in said chamber and said flow passages with said one lid in said closed position and being movable automatically into a closed position relative to a respective valve seat with said one lid in said open position.

Two embodiments of the valve according to the invention are illustrated in the accompanying drawings wherein: Fig. 1 is a sectioned view in side elevation of a first embodiment; ■' \ cD > 0* V ■*- 5OCT 1992 ,V ^ 23415 3 Fig. 2 is a sectioned view in side elevation of a second embodiment, and Fig. 3 is a sectioned view in side elevation of another embodiment.

Referring to Fig. 1 a valve body comprises parts 1, 2 which are screwed together and co-operate to bound a chamber 3.

The part 1 has a passage 4 with a connection for a relatively low-pressure gas, such as natural gas at a pressure of less than 200 mbar. The passage 4 is formed with a screwthread for a screwed connection to a gas feed line (not shown). Also, the top part 2 of the body has a passage 5 with a gas connection to chamber 3, the latter connection being at a relatively high connection pressure, and a load connection which has a passage 6 formed with a connecting screwthread extends from the chamber 3.

The passage 4 terminates at a seat 7 closable by a lid 8 carrying a ring seal 9. The passage 5 terminates at a seat 10 whose free cross-section is much smaller than that of the seat 7 and which is closable by a lid 11 mounted in a magnetizable armature 12 adapted to be moved upwards as illustrated in the drawings by a magnetic force such as is produced by the energization of a coil 13. The armature 12 slides in a cylindrical bore in the top part 2 and is formed with a longitudinal groove 14 to provide a connection between the top part of the latter bore and the remainder of the chamber 3.

A cylindrical cavity 16 is present in the armature 12 and terminates at the top in an inner shoulder 17 which retains the lid 11 in the armature 12. A spring 18 with a cap 19 pushes the lid 11 upwards, the spring 18 bearing at its bottom end on a closure member which closes a top part of the cavity 16. The function of the bottom convex surface 21 of the member 20 is to co-operate with a transmission port 32 of the lid 8, and port 32 being cylindrical and moving in an appropriate cavity in the armature 12. A spring 22 bearing at one end on the body top part 2 and at the other end on a collar 23 at the bottom of the armature 12 biases the same downwards - i.e., in the opening direction away from the seat 10. 234153 4 As Fig. 1 shows, at the top outer edge of the lid 8 there is a bead-like member 36 in bearing relationship with a bottom part of armature cavity 16; the same terminates at the bottom in a bead 37 which co-operates with the member 36 to prevent the lid 8 from dropping right out of the cavity 16 during assembly. This arrangement results in a connection with backlash between the lids 8 and 11 and allows the lid 8 to close on its seat 7 when the lid 11 closes on its seat 10.

The function of the valve described here is to convey a gaseous medium through the passages 4, 6 into a buffer tank from which the medium is extracted and compressed by a compressor (not shown) to a much higher pressure of the order of magnitude of 200 bar for farther processing such as the charging of high-pressure accumulators. The high-pressure gas passes through the passage 5, the same being formed with a tapped bore 25 associated with a screw 24 for controlling the gas throughflow.

When the compressor starts the valve is energized and the armature 12 moves into its top end position so that the lid 11 keeps the seat 10 closed. Once the extracting compressor causes the pressure in the passage 6 to drop below the pressure in the passage 4, the lid 8 unseats to allow the gas to pass from passage 4 to the passage 6 and to the buffer tank. Advantageously, to stop the compressor the pressure in the compressor outlet line connected to the passage 5 is first reduced. Energization of the coil 13 ceases and the spring 22 forces the armature 12 downwards. When the lid 11 disengages the seat 10, the pressure in the chamber 3 rises and acts to close the lid 8 on to the seat 7 like a check valve. Gas feeding is now interrupted and the higher-pressure gas goes through the groove 14 to the chamber 3 and onwards through passages 6 into the buffer tank, the gas flow being retarded by the resistance of the screw 24.

The buffer tank has a much larger volume than the high-pressure feed line so that the equalizing pressure becomes much lower, for example, of the order of magnitude of 3 bar. When the compressor restarts the seat 10 is closed by way of the armature 12 and the equalizing pressure in the passage 6 decreases until the pressure in the passage 4 is higher than in the passage 6 and lifts the lid 8, thus ensuring that there is substantially no 23415. flowback into the supply network through the passage 4. In the embodiment of Fig. 3 the sliding friction between the disengaging armature 12 and the lid 8 is also Uiken into account, a projecting O-ring 38 which is made of a soft elastomer being let into the seat 7, an additional spring element 39 pressing the lid 8 on to the O-ring 38. This feature of building up a metered barrier gas buffer is interesting for handling all gases which must not contact the atmosphere but is also useful when the gas is merely air.

The embodiment of Fig. 2 differs only in minor aspects from the embodiment of Fig. 1 and like elements have the same reference numerals in both Figures.

In the embodiment of Fig. 2 the casing bottom part is combined from three parts 27 - 29 held together by screws 30. The parts 27, 29 co-operate to bound a circular inner groove in which a diaphragm 31 engages by way of its outer edge. The same diaphragm 31 forms an inner ring 33 which can readily be moved axially between, and provides sealing-tightness between, the lid 8 and its seat 7, In this case the seat 7 is supported in the part 29. The lid 8 merely slides in a guide of the armature 12 and is pressed by the collar 23 at the bottom of the armature towards the seat 7. O-rings 34, 35 provide static sealing between the casing pans 27 - 29, The advantage of this construction is that the top part of the valve comprising the parts 27, 29 can be preassembled. The delicate pans of the valve, more particularly the seat 7 and the diaphragm, are therefore protected and run no risk of being damaged before final assembly on the bottom part 28. The preassembled unit comprises two parts 27, 29 which can be replaced by a single part formed with a slot to receive the diaphragm edge and having a relatively substantial screwthreaded fastening to the casing top part, for assembly of the diaphragm. «• ? r * i't i 0 '■J1"'' ?34 o

Claims (14)

WHAT WE CLAIM IS:

1. A three-way valve comprising a body having a chamber therein, three flow passages extending outwardly from said chamber, a first valve seat between said chamber and one of said passages and a second valve seat between said chamber and a second of said passages: a first valve lid in said body for seating on said first valve seat to control a flow through said one passage; a second valve lid in said body for seating on said second valve seat to control a flow through said second passage; and means for controlling the movement of said valve lids, said means including a single actuating element for moving one of said lids from an open position to a closed position relative to a respective seat with the other lid being movable independently of said actuating element under the pressures prevailing in said chamber and said flow passages with said one lid in said closed position and being movable automatically into a closed position relative to a respective valve seat with said one lid in said open position.

2. A three-way valve as set forth in claim 1 wherein said actuating element is a magnetizable armature siidably mounted in said body along a displacement axis, said one lid being supported b^aid*-^. ft \\ v ^ 16 OCT i992*f "■ r. _ /' 'A .A iH ft. - <$'. " <? £ ! armature coaxially of said axis and said other lid having an axial guide section on said axis.

3. A three-way valve as set forth in claim 2 wherein said means includes a spring between said body and said other lid for biasing said other lid onto said respective valve seat.

4. A three-way valve as set forth in claim 2 wherein said other lid has a slideway opposite said armature for axial guidance of said other lid.

5. A three-way valve as set forth in claim 2 wherein said other lid has a slideway opposite a guideway of said body.

6. A three-way valve as set forth in claim 2 wherein said guide section of said other lid is slidably mounted in said armature.

7. A three-way valve as set forth in claim 6 wherein said other lid has an annular flange and said armature has an annular collar for abutting said flange to effect movement of said other lid into a closed position thereof.

8. A three-way valve as set forth in claim 2 wherein said valve seat for said one lid is of a smaller diameter than said other valve seat whereby said one lid controls a gaseous medium at a higher pressure than a medium controlled by said other lid.

9. A three-way valve as set forth in claim 8 which further comprises means in said passage controlled by said other lid for retarding a flow therethrough. 16 OCT 1992* ft i 8 •-•M i

10. A three-way valve as set forth in claim 2 which further comprises an elastomeric diaphragm between said other lid and said respective valve seat, said diaphragm being connected to said body to provide an axially displaceable annular surface between said other lid and said respective valve seat.

11. A three-way valve as set forth in claim 10 wherein said body is formed of three parts; a first of said parts having two of said passages therein, a second of said parts having one of said valve seats thereon and bounding an annular recess with a third of said parts, said diaphragm being secured between said second and third parts in said recess.

12. A three-way valve as set forth in claim 2 which further comprises an elastomeric ring in said valve seat for said other lid for seating of said other lid thereon.

13. A three-way valve as set forth in claim 2 ^ which further comprises retaining means with backlash y between said armature and said other lid. J 14. A three-way valve comprising a body having a chamber therein, three flow -""•h passages extending outwardly from said chamber, a first w' valve seat between said chamber and one of said passages and a second valve seat between said chamber and a second of said passages; a first valve lid in said body for seating on said first valve seat to control a flow through said one passage; a second valve lid in said body for seating on said second valve seat to control a flow through saidd^^!/?-second passage; and / * vf 17S KJ • fy ■"-"n W' 7 ,1 • > means for controlling the movement of said valve lids, said means including a magnetizable armature for moving said first lid from an open position to a closed position relative to said first valve seat with said second lid being movable independently under the pressures in said chamber and said passages with said first lid in said closed position and being automatically movable into a closed position relative to said second valve seat with said first lid in said open position. 15. A three-way valve as set forth in claim 14 which further comprises a coil for actuating said armature for movement from a rest position with said first lid in an open position relative to said first valve seat to an actuated position to move said first lid into a closed position on said first valve seat. 16. A three-way valve as set forth in claim 15 wherein said first lid is mounted coaxially in said armature and said second lid is mounted coaxially of said armature. 17. A three-way valve as set forth in claim 16 wherein said second lid is slidably mounted in said armature. 18. A three-way valve as set forth in claim 17 which' further comprises a spring' in said armature between said lids for biasing said lids away from each other and outwardly of said armature. 19. A three-way valve as set forth in claim 15 which further comprises a spring between said armature and said body for biasing said armature into said rest;^NF position thereof. :,v '" , •» n Stv 4 10 20. A three-way valve as set forth in claim 14 which further comprises a spring between said lids for biasing said second lid into said closed position thereof.

14. A three-way sea ted valve substantially as herein described with reference to the accompanying drawings. SULZER BROTHERS LIMITED By their attorneys HENRY HUGHES LTD