Abstract: A valve mechanism which is resiliently biassed towards a first position but is normally retained in a second position by means of a linkage including a chemically sensitive device which is arranged to release in the presence of a contaminant.

Abstract: A shear valve for use in a fuel delivery system includes a valve body wherein a first end is adapted to be connected to a fuel inlet, and a second oppositely-disposed end is adapted to be connected to a fuel outlet. The valve body is provided with a readily frangible or separable region between the first and second ends. The first end has an emergency shut-off valve biased towards a closed position, and is normally held open by a displaceable abutment having one ball or roller.

Abstract: A valve mechanism which is resiliently biassed towards a first position but is normally retained in a second position by means of a linkage including a chemically sensitive device which is arranged to release in the presence of a contaminant.

Abstract: A fuel storage tank is disclosed which is fitted with an overfill protection device for automatically shutting off flow of fuel into the tank when the fuel reaches an intended maximum fill level. The overfill protection device comprises a fill valve located in a fuel fill tube and linked to a diaphragm or piston which is displaceable within a chamber, said chamber communicating with an aperture which is arranged to vent the chamber into the tank. The device may include a float valve for controlling the aperture and maintaining the aperture closed until fuel in the tank reaches a predetermined fill level, whereupon the aperture is opened and the piston or diaphragm is displaced to cause closure of the valve.

Abstract: An air transfer valve is disclosed comprising a housing (8) having an inlet (21) and an outlet (22), the outlet being controlled by a first non-return, valve (28) which is biased to its closed position and the outlet being controlled by a second valve (30) which is normally in its open position, the first valve being caused to open by an increase in air pressure within the valve but closing in response to reduced pressure. The valve is intended to be fitted into a fill pipe (1) of a fuel storage tank so that the outlet communicate with the tank ullage through an aligned hole in the wall of the fill pipe. In this situation, the valve transfers air from the fill pipe into the ullage and reduces turbulence which would otherwise cause excessive generation of vapor during tank filling (FIG. 1).

Abstract: In a fuel storage tank having a fill pipe arranged to discharge within the tank below the normal liquid level in the tank, an air transfer valve is mounted within the fill pipe above the normal maximum liquid level, the valve being normally closed and having an outlet communicating with the head space in the tank and an inlet directed away from the direction of fluid flow in the fill pipe. An operating mechanism within the valve opens the valve in response to increased pressure in the fill pipe arising from air or vapour carried by fuel flowing in the pipe. The air transfer valve is preferably attached to the inside of the fuel pipe just above the normal maximum liquid level. The operating device within the air transfer valve may be a valve which is normally held in its closed position by gravity or a light spring closure force.