GB2310263A

GB2310263A - Valve in vapour recovery line of fuel delivery system

Info

Publication number: GB2310263A
Application number: GB9602088A
Authority: GB
Inventors: Barry Charles Risbridger; Paul Richard Chawner
Original assignee: W&J Risbridger Ltd
Current assignee: W&J Risbridger Ltd
Priority date: 1996-02-02
Filing date: 1996-02-02
Publication date: 1997-08-20
Also published as: GB9602088D0

Description

VAPOUR RECOVERY LINE SHEAR AND TEST VALVE This invention relates to a vapour recovery line shear and test valve intended for use on a petrol pump delivery system.

It is becoming increasingly a requirement that dispensing of fuel to motor vehicles should be accompanied by recovery of vapour displaced during the filling operation. Therefore, the petrol delivery pump, in addition to having a fuel delivery line from an underground fuel tank, will also include a vapour recovery line which is plumbed into the vapour vent line of the underground storage tank itself.

This is illustrated in Figure 1 of the accompanying drawings which shows diagrammatically the connections to an underground storage tank.

Referring to Figure 1, the storage tank 1 is connected to the petrol pump 6 via a suction line 2 and also is connected to a vapour vent line 3 which may be connected to a single vent line 4 or a manifolded vent line 5, connected also to other fuel storage tanks. The delivery pump 6 also incorporates a vapour recovery line 7 which is connected to the main vapour vent line 3, or direct to the top of the storage tank (e.g. to the man lid).

At the point of delivering the fuel, a delivery hose and nozzle may be used which can be sealingly engaged with the fuel tank and delivers fuel through an inner coaxial tube while recovering vapour through an outer annular tube. One typical system of this kind is available from Dover International B.V. of Zwanenburg, the Netherlands, and is sold as the OPW 1 1-VF Vapour Recovery Nozzle. While the fuel is being delivered to a vehicle, vapour is taken back to the vapour vent line 3 via the line 7, or back to the storage tank.

There are two problems with this system. First, if the delivery pump is damaged in an accident, the vapour recovery line may be broken and vapour will be allowed to escape from the underground fuel tank to the atmosphere, causing an immediate and serious fire risk. A second problem is that there is a need from time to time to test the integrity of the vapour vent lines, usually by making a pressure test. This cannot be made if the vapour recovery line 7 is open.

The present invention provides a solution to these problems and this is described in the accompanying Figures 2 and 2A.

According to the present invention there is provided a valve for use in a fuel delivery system which comprises a valve body having two connected parts which are severable from one another if the valve sustains a physical bending movement, each of said connected parts having a valve mounted therein which is normally open, the valves being arranged to close automatically in the event that said connected parts are severed or damaged.

Referring to Figures 2 and 2A, a valve 12 is located beneath the petrol pump to control the vapour recovery line 7. The valve comprises a body 14 manufactured in two housing parts 16 and 18, which are joined or latched together at 17 in fluid-tightre-useable manner. Two longitudinally spaced valves 20 and 21 are mounted within the body. Valves 20 and 21 have respective valve stems 19a and 19b which normally butt against each other at a point 23, which is located in the region of the joint between the housing parts 16 and 18. Thus, in the event of a collision, the housing part 16 will break away from the lower part 18 and the valves 20 and 21 will both close in opposite directions under the influence of springs 25 and 28.

An eccentric cam 24 extends through the lower part of the body 18 and in the normal working position, does not contact the valve spindle 19. Springs 25 and 28 tend to urge the valve stemLl9b in opposite directions. However, the relative strengths of the springs are selected so that both valves are raised off their valve seats so that vapour may flow in the direction of the arrow from the dispenser back into the tank. Alternatively, the spring 25 is stronger than spring 28 and tends to push the stems 19a,19b downwardly. The valve 20 is prevented from closing onto its seat by the stem 19b abutting the surface of the cam 24.

However, in the event that the valve is damaged, e.g. by a collision, and the top portion 16 is broken off, the lower valve 21 is no longer restrained by the upper part of the valve and will automatically close onto the seat 26 under the action of spring 28.

If the top part 16 of the valve is broken off, it remains connected to the fuel dispenser. However, in the absence of the restraint imposed by the cam surface and/or the spring 28, valve 20 will close onto its seat 30 and will prevent vapour escaping from the fuel dispenser.

Should it be desired to pressure test the line 7 back to the tank, such a pressure test can be made through the port 27 in the lower part of the housing 18. In order to make such a test, the eccentric cam is turned so as to push the 6 spindle l 9tupwardly against the action of the upper spring 28, thereby closing the lower valve 21 against its seat 26. A pressure test can then be made through the test port 27. Such a pressure test can be conducted using the technique and apparatus described in UK Patent Application No. 9306893.0 (Publication No.

2265988) or by similar methods.

As indicated in Figure 2A, the valve body may be grooved, e.g. at 31 for attachment by it bolt fixing or provided with four apertured lugs 32 for through bolting into the base of the delivery pump and subframe.

Claims

CLAIMS: - 1. A valve for use in a fuel delivery system which comprises a valve body having two connected parts which are severable from one another if the valve sustains a physical bending movement, each of said connected parts having a valve mounted therein which is normally open, the valves being arranged to close automatically in the event that said connected parts are severed or damaged. 2. A valve as claimed in claim 1 wherein the connected parts are adapted to separate under a physical impact which is insufficiently severe to cause damage to the connected parts, whereby at least one of the valves and its associated housing part is re-useable. 3. A valve as claimed in claim 1 or 2 wherein the valves each have valve stems and are mounted in the valve body with their valve stems aligned and abutting in the region where the two connected parts of the valve body are joined. Amendments to the claims have been filed as follows CLAIMS:-

1. A valve for use in a fuel delivery system which comprises a valve body having two connected parts which are severable from one another if the valve sustains a physical bending movement, each of said connected parts having a valve mounted therein which is normally open, the valves being arranged to close automatically in the event that said connected parts are severed or damaged.

2. A valve as claimed in claim 1 wherein the connected parts are adapted to separate under a physical impact which is insufficiently severe to cause damage to the connected parts, whereby at least one of the valves and its associated housing part is re-useable.

3. A valve as claimed in claim 1 or 2 wherein the valves each have valve stems and are mounted in the valve body with their valve stems aligned and abutting in the region where the two connected parts of the valve body are joined.

4. A fuel delivery system including a fuel supply line and a vapour recovery line, said system including a valve as claimed in any one of the preceding claims located in the vapour recovery line or in the fuel supply line.