GB2309760A - Road tanker line - fuel storage tank line coupling with valve(s) - Google Patents

Abstract

A road tanker fuel hose is coupled to a fill conduit of a fuel tank, said coupling comprising a fill conduit-coupled part 20 incorporating a valve 23 biased into its closed position, and a fuel hose-coupled part 30 having a movable probe 33 which, when extended, opens the valve and means for extending the probe after said two parts have been coupled together. A vapour vent line from the tank is coupled to a vent line from the tanker, using the part 30 and a coupling part incorporating a valve biassed closed but also having a sleeve valve which connects the tank line to a vent to atmosphere whilst preventing the valve to the tanker line opening, allowing such to open when the connection to atmosphere is blocked. An intermediate coupling part can be inserted between the two parts; it has a valve and a vapour flow indicator comprising a swinging flap and scale.

Description

SYSTEMS FOR COUPLING TANKERS TO FUEL TASKS This invention relates to systems for coupling tankers to fuel tanks and is concerned with the problems of unloading fuel into a fuel tank while minimising escape of vapour.

There are continuing environmental pressures to reduce the escape of vapours of fuels such as petrol and diesel oil during delivery from a tanker such as a road tanker. In order to limit vapour escape into the atmosphere, it is now the practice for road tankers to be connected to an underground fuel tank by two hoses during the filling operation. The first of these hoses transfers fuel from the road tanker through the filling line to the tank, while the second line is connected to a line connected to the head space of the tank and recovers vapour which is displaced from the tank during the delivery of the fuel. Despite this system, some vapour can still escape during the filling operation and the primary object of this invention is to further reduce or eliminate such escape.

According to one aspect of the present invention there is provided a hose coupling, especially for connecting a road tanker fuel hose to a fill conduit of a fuel tank, said coupling comprising a first part adapted for connection to the fill conduit or the tanker hose and a second part adapted for connection to the other of the hose and the fill conduit, said first part incorporating a valve biased into its closed position, and the second part having a movable probe which in its extended position is capable of opening the valve and means for extending the probe to open the valve after said two parts have been coupled together.

As a result of the improved coupling described above, vapour or fuel cannot be forced out of the offset fill line until a hose is coupled onto the fill line and will then flow back to the tanker.

Another point at which vapour is sometimes leaked to the atmosphere is from the vapour recovery line. There have also been problems in vapour leakage since the tank remains connected to a vapour vent line when the tank is connected to a vapour recovery hose of a road tanker. The problem of vapour escape may also arise because pressure may build up in the tank and this is released when the tanker hose is connected to a vapour vent line having an overpressure relief valve.

The above problems may be overcome in accordance with this invention by providing a coupling for connecting a vapour recovery hose to a vapour vent line from a fuel tanker, said coupling comprising a part connected to the vapour vent line and having a first valve operable by a probe on the hose coupling when the hose coupling and the vent line are coupled together, a second valve which in a first position connects the head space of the tank to a vent pipe to atmosphere and in a second position connects the head space to said first valve, the first and second valves being interlocked so that the first valve cannot be opened to connect the head space with the vapour recovery hose, while the second valve is in its first position.

Occasionally, it is helpful to have some indication during the unloading of a road tanker of the rate of flow of vapour back to the tanker. A low rate of flow may, for example, be indicative of vapour leaking from elsewhere in the system. The inventipn, therefore, further provides a simple flow indicator which may be interposed between the vapour vent line and the tanker.

Conveniently, it is housed in a separate unit which is fitted between the vapour vent line and the tanker hose.

Further features and advantages of the present invention will be apparent from the following description and accompanying drawings, in which: Figure 1 is a schematic view of a fuel tank storage and delivery system, Figure 2 is a section through one part of a coupling for fitting to the fill line of an underground fuel tank, Figure 2A is an end view of the tanker half coupling for fitting to the coupling part shown in Figure 2, Figure 2B is a section along the line A-A in Figure 2A, Figure 3 is a section through a fitting for attachment to the end of a vapour vent line Figure 3A is a section along the line A-A in Figure 3, and Figure 4 is a view partly in section of a coupling which incorporates a vapour flow detection device.

Referring to Figure 1 of the drawings, this shows a fuel tank installation having an underground fuel tank 1 which is connected via an offset fuel line 2 to a filling access point 3, and to a suction line 4 to a petrol pump 5 for delivering fuel to retail customers. The head space 6 of the tank is vented via a vapour vent line 7, either to a single vent line 8 or more usually in modern installations to a manifold 9 which is connected to a number of other underground fliel tanks.

The manifold 9 includes a vent pipe 10 through which all the manifold vent lines can vent to atmosphere, and also to a fitting 11 through which vapour can be recovered back to a road tanker during off-loading of fuel to the underground storage tank. The vent, pipes 8 and 10 usually include a pressure relief valve 12a,12b which is set to release vapour to atmosphere at a lower over-pressure of about 1-2 psi. The couplings and other fittings to be described and which relate to the present invention are intended to be fitted to points 3 and 11 of the fuel tank installation.

Referring first to Figures 2, 2A and 2B, these illustrate the two parts of an adaptor and hose coupling which will be connected at the unloading point 3.

Figure 2 is a section through an adaptor 20 which will be fitted to the end of the offset fuel line 2. Adaptor 20 comprises a body portion 21 threaded at 22 for attachment to the end of the offset fuel line and fitted with a poppet valve 23 which is spring-biased into its closed position, seating against a curved or other corresponding shaped face 24 of the inlet port 25 of the adaptor Valve 23 includes a spindle 26 designed to slide axially in a bore in a projection 27 in the direction of the arrow to open the valve.

The valve is designed to be opened by a probe fitted to the tanker hose once the two parts of the coupling are brought together. However, in order to prevent any pressurised vapour or fuel in the offset or direct fill fuel line from escaping during the coupling operation, the hose coupling is designed so that valve 23 is only manually operable once the coupling is securely made.

Referring to Figures 2A and 2B, the half of the coupling which is fitted to the tanker hose comprises a body portion 30 having suitably shaped grooves 31 for connection to a hose and latches 32 for engagement in a groove 28 of the part 20 for coupling the parts together. The hose coupling part 30 incorporates a probe 33 which in its extended position is able to open the valve 23 by pushing on the face of the poppet valve. However, in the position shown in Figure 2B, the probe 33 does not quite touch the face of the poppet valve when the two halves are coupled together.

After the coupling has been connected, the probe 33 can be extended by rotating a spindle 34 which is geared to e.g. a rack 35 on the probe 33. This causes the probe 33 to be extended, thus pressing open the valve 23 and allowing any vapour to flow from offset fill line 2 into the tanker hose and back to the tanker. Spindle 34 is movable by an operator lever 36 which is attached to the end ofthe spindle.

After the required amount of fuel has been off-loaded into the underground fuel tank, the probe 33 can be operated once more by returning it to its original position, thus closing the valve 23 and preventing any escape of vapour before the coupling is dismounted and returned with the hose to the tanker.

Figures 3 and 3A, show a device for connection to the vent line manifold at the point 11 shown in Figure 1. The device comprises a body 50 having a threaded recess 51 for connection on the end of the vent line manifold 9. The body includes a port 52 for connection to a vent line such as 10 as shown in Figure 1.

At the right-hand end of the fitting as shown in Figure 3, a poppet valve 55 normally closes off access to the vapour line and is spring-biased with a spring 56. Valve 55 includes a spindle 57 which extends back into the body of the adaptor. Valve 55 seats against a surface of the port 53 in an analogous manner to the poppet valve 23 in the coupling shown in Figure 2. It is also envisaged that in use, a tanker's vapour recovery hose would be fitted with a coupling similar to that shown in Figure 2B, so that the coupling shown in Figure 2B could be connected to the end 54 ofthe body 50 and, on operating the probe 33, cause the valve 55 to open so that the vapour vent manifold is connected via the vapour recovery hose back to the tanker.

The interaction of valve 55 and the coupling shown in Figure 2B prevents vapour escaping to atmosphere from the vent line 7 or manifold 8. while the tanker recovery hose is being connected to the end 54 of the coupling shown in Figure 3. Once this connection has been made, the lever 36 can be operated to place the interior of body 50 in communication with the tanker recovery hose.

In order to prevent escape of vapour through the vent line to atmosphere during the filling of the fuel tank, a second valve 58 is provided within the body 50. Valve 58 is a sleeve valve comprising a sleeve 59 which is shown in the closed position in Figure 3. In this closed position, vapour may flow from the manifold 9 through the body 50 and (if valve 55 is open) into the vapour recovery hose. In this position of valve 58, poppet valve 55 can be opened by operating lever 36 because the spindle 57 can move towards the right, as shown in Figure 3, without impinging on the spindle 60 which forms the central portion of valve 58.

It will be appreciated that when valve 58 is in its closed position, vapour cannot escape along vent line 10 because the sleeve 59 covers the access to port 52. However, in order to protect the tank against possible damage caused by a sudden and excessive pressure build-up, an over-pressure relief valve 61 is provided in the sleeve 59. Pressure relief valve may, for example, be set to open at a pressure of about 3 psig.

Valve 58 has an open position in which the sleeve 59 is moved to the right (as shown in Figure 3). The position of the spindle 60 is shown in dotted lines in the open position of the valve and it will be observed that in this position, the spindle 60 abuts the end of valve stem 57. Because of this abutment, poppet valve 55 cannot be opened while the sleeve valve 59 is open. Therefore, unloading of fuel into the tank 1 cannot commence until the sleeve valve 58 is moved to its shut position. Movement of valve 58 between shut and open positions is effected by operation of lever 62. Lever 62 carries a pinion 63 which engages a rack 64 formed on the outside of spindle 60. It will be appreciated that the normal position of valve 58 is in the open position and lever 62 may be locked, e.g. with a padlock, in this position so that in normal operation of the fuel tank installation, the tank can breathe through the vent pipe 8 or 10.

Referring to Figure 4, this shows a coupling which it is intended to be fitted between the coupling point 11 and the tanker hose. Conveniently, the coupling would be an additional temporary test section fitted to the end of the tanker hose, although it could be incorporated as part of the vehicle vapour recovery hose. The coupling comprises a body 70 at one end of which are coupling latches 71 similar to those shown in Figure 2B.

The device also includes a probe 72 for opening a valve such as valve 55 in the fitting shown in Figure 3. The other end 73 of the adaptor incorporates a spring-biased poppet valve 74 which is similar in construction to valve 55 shown in Figure 3. Accordingly, the adaptor can be attached to the end 54 of the fitting 50 and the valve opened by the probe 72, and the other end 73 of the adaptor can be coupled to a coupling such as shown in Figure 2B of a tanker vapour recovery line.

The fitting includes a vapour flow indicator 76 within the body 70 (viewable through a viewing glass 79) and comprising a swinging flap 77 which moves in response to vapour flow along the fitting. A scale 78 may be provided to give a measure of the amount of vapour flowing through the vapour recovery line.

Claims (2)

CLAIMS: -

1. A hose coupling, especially for connectino a road tanker fuel hose to a fill conduit of a fuel tank, said coupling comprising a first part adapted for connection to the fill conduit or the tanker hose and a second part adapted for connection to the other of the hose and the fill conduit, said first part incorporating a valve biased into its closed position, and the second part having a movable probe which in its extended position is capable of opening the valve and means for extending the probe to open the valve after said two parts have been coupled together.

2. A coupling for connecting a vapour recovery hose to a vapour vent line from a fuel tanker, said coupling comprising a part connected to the vapour vent line and having a first valve operable by a probe on the hose coupling when the hose coupling and the vent line are coupled together, a second valve which in a first position connects the head space of the tank to a vent pipe to atmosphere and in a second position connects the head space to said first valve, the first and second valves being interlocked so that the first valve cannot be opened to connect the head space with the vapour recovery hose, while the second valve is in its first position.