AU605918B2

AU605918B2 - Improved liquid petroleum multi-valve assembly

Info

Publication number: AU605918B2
Application number: AU23682/88A
Authority: AU
Inventors: Peter Chapman; John Donaldson; Andrew Foulkes; Don Jones
Original assignee: MYTTON S Ltd
Current assignee: Syntom Ltd
Priority date: 1987-10-16
Filing date: 1988-10-12
Publication date: 1991-01-24
Anticipated expiration: 2008-10-12
Also published as: AU2368288A

Description

AUSTRALIA

PATENTS ACT 1952 COMPLETE SPECIFICATION 605 1 Form

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: Complete Specification-Lodged: Accepted: Lapsed: Published: 2 ar 4 9 t 1 I i Priority: Related Art: This do-,umne]A contains tc I aienclmnts ma1de uucifr Section 49 a .d is co-ect for prining.

TO BE COMPLETED BY APPLICANT Name of Applicant: Address of Applicant: Actual Inventor: S Address for Service: S t 'i MYTTON'S LIMITED 10 Mirra Court, Bundoora, Victoria, 3083, Australia GRIFFITH HACK CO., 601 St. Kilda Road, Melbourne, Victoria 3004, Australia.

rril Complete Specification for the invention entitled: IMPROVED LIQUID PETROLEUM MULTI-VALVE ASSEMBLY The following statement is a full description of this invention including the best method of performing' it known to me:- -1- This invention relates to a liquid petroleum gas P. multi-valve assembly for a tank for L. P. G.

to be mounted, for example, in a luggage compartment of a vehicle.

Due to substantial increase in the cost of petrol, the use of L. P. G. which has similar combustible properties to the air/fuel mixture of a conventional petrol engine, has become more popular, However, there are some potentially dangerous differences with the use of L. P. G. The fuel is retained in steel cylinders under extremely high pressures and accordingly the standards of safety are very strictly controlled.

It is currently required that the L. P. G. cylinder

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must be provided with a multi-valve assembly wherein all valve functions must be within the tank itself.

These valves comprise, inlet and outlet valves, a pressure relief valve and an ullage valve which determines that the level of liquid gas withing the cylinder does not exceed 80% of its capacity.

Conventionally, these valves and/or their connections have been housed in a container mounted externally of the tank but changes in safety standards j now require them to be mounted within the tank.

It is an object of the present invention to provide a multi-valve assembly which complies with the safety standards and which is more efficient in its operation, especially as regards relief of excess pressure.

-1 a- 2 According to the present invention a multi-valve assembly comprises a body adapted for detachably securing the assembly to a liquid petroleum gas cylinder whereby the body is substantially wholly retained within said cylinder, said body, including an excess flow valve and fill limiting and pressure relief valves, located in part of the body confined within the boundary of the cylinder, said pressure relief valve being in straight line communication with the interior and exterior of the cylinder.

SA multi-valve assembly in accordance with one form of the invention which may be preferred is now hereinafter described with reference to the accompanying drawings, in which; Figure i, is a perspective view of the assembly, Figure 2, is a cross-sectional view taken along the line 2-2 of Figure 1, Figure 3, is a cross-sectional view taken along the line 3-3 of Figure 2, Figure 4, is an enlarged sectional view of the ullage valve and taken along the line 4-4 of Figure 1, Figure 5 is an enlarged cross-sectional view of the pressure relief valve and taken along the 23 line 5-5 of Figure 1 and Figure 6 is a cross-sectional view taken along the line 6--6 of Figure 3.

As shown in the accompanying drawings, a multi-valve assembly comprises a substantially circular mounting flange 10, preferably of brass, and having a plurality of apertures 11 for receiving retaining screws for detachably securing the assembly to an opening in the L. P. G. cylinder. The underside of the flange is provided with an annular groove fitted with an "O" ring seal 12 to ensure effective sealing of the assembly on the cylinder.

o 1.0 The body 10 is provided with an inlet aperture 13, S .o o an outlet 14 and a service valve retaining screw opening 0* 15 in the side thereof and service and ullage valve oo o openings in the top surface thereof. The top of the body 10 has a service valve actuation knob 17 mounted thereon which is the only protruding item.

o The body is provided with an axial passage 18, the St upper portion of which retains the service valve 19 and r ,rthe lower portion of which retains the excess flow valve 41 i 20. The body is also provided with a further passage 21 20 for retaining a pressure relief valve assembly 22 (see Figure As will be seen from Figure 2, the inlet valve assembly comprises a pipe connection 23 adapted to be Sthreadedly retained in the opening 13 in the body, the connection 23 having an enlarged axial bore 24 for receiving and retaining a spring-loaded non-return valve A passage 26 connects the bore 24 with the axial -3- 1 3o 1 03 0 A a oo o no n 00 a do 00 0 ro a 0 0 S£3 0 00 t« 4 20 25 i) l J l i i 11; It; 2 passage 18. The excess flow valve 20 at the lower end of the passage 18 has a tube 27 which extends into the cylinder and substantially to the bottom thereof. The valve 20 comprises a seal 28 which during filling of the cylinder, is held on its seating by means of a spring 29 to close the excess flow tube. The seal is lifted off its seat to open the valve 20 during normal operation of the vehicle engine but should the flow of fuel become excessive as a result of accidental damage to the pipe line or otherwise, the valve 20 is closed on an upper seat 28A to prevent escape of gas.

The ullage valve 30 as shown in Figure 4 is an additional safeguard against overfilling. This valve provides a manual check and comprises a threaded spool 31 which on actuation by a screwdriver causes the valve to be opened or closed. When open, the valve and its porting are arranged to discharge liquid once the cylinder reaches approximately 80% full. The lower end of the passage containing the ullage valve is in the bottom of the valve body and when secured in the cylinder, this opening is at a level which corresponds with 80% of the capacity of said cylinder.

Automatic filling to 80% is controlled by a fill limiting valve 32. This valve 32 is carried by a drum 33 which is rotated on pivots 51, 52 and is actuated by a float 34 and arm 35. As will be seen from Figure 6, the drum 33 is housed in an arcuate member 53 having a hole or slot 54 which is arranged to receive the shaft of the valve 32 when the float and arm have caused the member 53 to rotate an amount which is predetermined to correspond with an 80% fill of the cylinder. During filling, the valve 32 is forced from its seating at the opening 18A in che body by pressure of the filling fuel and is prevented from seating on the valve seat 50 of the drum 33 by said arcuate housing thereby permitting the fuel to flow around the valve 32 through an opening or passages 56 in the drum, and into the cylinder. When the cylinder is filled to 80% of its capacity the hole o or slot 54 in the housing is aligned with the valve stem a 4 a and the pressure of the fuel being introduced causes the valve stem to enter the hole or slot 54 and the at a o valve to seat against the valve seat 50, thus preventing flow of fuel into the cylinder. As soon as filling is discontinued and the pressure on the valve 32 is thereby a ~released, the valve is closed on its seat at the opening oo a 18A by means of a compression spring 36. This valve is oQ4 ,oa maintained in this attitude until fuel under pressure is introduced at the next filling operation.

a A level sensor 37 may be of known kind comprising a magneto resistor mounted onto a silicon wafer with suitable terminations, wires and connectors. The i transducer 37 is mounted on the side of the body 10 and S 25 is actuated by a cylindrical magnet 38 mounted in the end of the float valve rotating drum and separated from the transducer by the brass body of the valve. The level sensor 37 is connected to gauge means to indicate the level of fuel in the cylinder.

A pressure relief valve 22 as shown in figure 5 is Salso provided in the body 10. This valve, which is an important improvement over previous pressure relief i valves, is retained in a straight passage extending between the base of the body retained within the cylinder and the top of the body which is located on the i outside of the cylinder.

The valve 22 is substantially tubular in form but Sof lesser diameter than the diameter of the passage 21.

The lower end of the valve is closed and incorporates an elastomeric seal 42 for seating on an upstanding valve seat 43. The tubular wall of the valve is provided with cut-out sections 22A and the top of the valve is provided with an enlarged circumferential collar 22B for receiving a compression spring 44. Adjustment of pressure exerted by the spring 44 on the valve 22 is achieved by providing a threaded retainer 45 which is of such internal dimension as to comfortably receive the top of the spring 44. The retainer 45 has an axial opening 45A of diameter substantially equal to the internal diameter of the tubular valve 22.

The cut-out sections 22A of the valve 22 allow gas to flow therethrough to the hollow centre of the valve when excess pressure lifts the seal 42 off its seat 43.

The opening 45A in the threaded retainer enables escaping gas which passes through the cut-outs 22A in the valve and passed the spring 44 to pass through the retainer and passage 21 and into the L. P. G. tank sub-compartment.

-6- A blow-out plug 46 normally seals the open outer end of the passage to prevent the ingress of dust or other foreign matter to the assembly.

The service valve 19 is retained in the upper section of the passage 18 and is located in position by means of a grub screw 47, access to which is through the passage Filling of the cylinder is effected by connecting the inlet pipe connection 23 to a source of liquid under pressure. As the liquid is delivered, the valve 25 is forced off its seat and fuel is admitted to the cylinder via passage 18 and the opening in the lower part of the tit c body 10. The pressure of fuel forces the 80% fill valve 32 away from its seat thereby allowing the fuel to flow past the valve and into the cylinder through openings or passages in the valve housing. During this filling Ioperation, the excess flow valve 20 is closed.

Upon the liquid in the cylinder reaching capacity, the stem of the valve 32 is forced through the opening 54 in the outer surface of the valve housing causing the outer face 32A of the valve to seal against the seating 50. This prevents ingress of fuel to the cylinder. When the fuel flow is stopped and the pressure on the inner face of the valve 32 is released, the valve is caused to close the opening 18A from the passage 18 by its retaining spring 38.

Safety against over-filling is provided by the manually actuated ullage valve -7i In the event of pressure build-up within the cylinder exceeding a predetermined safety level, the gas is released by the lifting of the spool 41 from its seat, thereby allowing the gas a straight uninterrupted passage to atmosphere. By this arrangement, the discharge of gas is effected at a far greater rate than hitherto possible with prior art assemblies.

It will thus be seen that our assembly provides an improved multi-valve whereby all vital components are ir 0 housed within the gas cylinder and the pressure relief valve permits the gas to escape at a considerably faster 4# rate than previously known apparatus.

Thus, whilst we have described in the foregoing description, preferred forms of our invention, we do not wish to be limited to the positive terms employed

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herein, since many modifications and alterations may be S r r made by those skilled in the art without departing from the spirit and scope of our invention.

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Claims

2. An assembly as claimed in claim 1 wherein said body is additionally provided with valve controlled inlet and outlet passages for the admission and discharge respectively, of liquid petroleum gas to and from said cylinder.
3. An assembly as claimed in claim 1 or c3laim 2 wherein said body comprises an ullage valve as an additional safeguard against overfilling of the cylinder. S' 4. An assembly as claimed in any one of the tit 4II preceding claims characterized in that said pressure 4 A relief valve is mounted in a straight passage extending S through said body from a base portion of said body retained within said cylinder to a top portion of said body which is located outside of said cylinder. An assembly as claimed in claim 4 wherein said relief valve is mounted in said passage at or near the I base of the body.
6. An assembly as claimed in claim 4 or 5 wherein A spring means retain said relief valve closed; the pressure exerted on said relief valve by said spring being such as to permit the valve to be opened when pressure in said cylinder exceeds a predetermined level thereby permitting the discharge of gas through said relief valve and said passage to the exterior of said cylinder. ,®RA 4 T 0*e /VTos 10
7. An assembly as claimed in claim 5 or 6 wherein the relief valve comprises at least one longitudinal passage for the discharging gas to pass to an upper section of said passage and thence to the exterior of the cylinder when said relief valve is opened.
8. An assembly as claimed in claim 6 wherein said spring is interposed between said relief valve and a threaded retainer in said passage whereby the pressure exerted on the relief valve is adjusted by axial movement of said retainer.
9. An assembly as claimed in claim 6, 7 or 8 wherein the relief valve has a lower portion of greater diameter of than the valve seat and of lesser diameter than said passage, and is provided with at least one opening S therein communicating with at least one longitudinal passage in said valve body whereby when said valve is lifted from its seating, gas is discharged around said S valve seat to said space between said body and the wall of said passage and through said opening and said passage to the outside of said cylinder. An assembly as claimed in claim 9 wherein said lower portion of the relief valve is cylindrical and comprises a plurality of openings in the side wall thereof communicating with a central passage through the top of said valve body and said spring retainer.
11. An assembly as claimed in any one of the preceding claims wherein said fill limiting valve is adapted to shut off the delivery of liquid to the cylinder when the cylinder has been filled to substantially 80% capacity.
12. An assembly as claimed in claim 11 wherein said fill limiting valve has float controlled gate means allowing said valve to shut off the delivery of liquid to said cylinder when the level of liquid in the cylinder reaches substantially 80% full.
13. An assembly as claimed in claim 12-wherein said gate means includes an arcuate surface in contact with a stem of said valve during filling and has an opening 11 which permits the valve stem to enter therein and thereby close the valve when the float reaches its predetermined level.
14. A multi-valve assembly substantially as hereinbefore described with reference to the accompanying drawings. DATED THIS 21ST DAY OF 1990 MYTTON'S LIMITED By Its Patent Attorneys GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia t1 4$ A2Arn