Abstract

A vent system for a fuel storage tank and a pressure vacuum valve (PVV) module (110) for use with such a vent system are disclosed. The vent system defines a vent path (30) from the fuel storage tank (10) to atmosphere, comprising an elongate vent pipe (33) which extends vertically to a rain cap (300) located at the upper end of the vent pipe, and a pressure vacuum valve (PVV) (130) located in the vent path between the lower end of the vent pipe (33) and the tank (10). The pressure vacuum valve (130) maintains the vent path in a closed condition unless the pressure in the tank is above or below a predetermined pressure. By separating the PVV from the rain cap and placing it between the lower end of the vent pipe and the tank, it is possible to site the PVV at an accessible level for maintenance. The PVV (130) is located in a PVV module (110). The vent path deviates from the axis of the vent pipe to the pressure vacuum valve which is located in the module (110), in a position offset from the vent pipe axis. The module also includes an auto shut-off valve (120) and a condensate collector.

IPC Classes  ?

• B67D 7/04 - Apparatus or devices for transferring liquids from bulk storage containers or reservoirs into vehicles or into portable containers, e.g. for retail sale purposes for transferring fuels, lubricants or mixed fuels and lubricants
• B67D 7/32 - Arrangements of safety or warning devicesMeans for preventing unauthorised delivery of liquid

Abstract

A float valve is mounted within the ullage of a liquid storage tank and is fitted to a lower end of a vapour vent line. The float valve includes a generally tubular vent body having an opening arrangement which allows vapour to escape from the tank into the vent line, and a float assembly which undergoes damped upward movement in response to the liquid level within the tank exceeding a threshold level. The float assembly comprises a sleeve and a float arrangement separated from each other by an adjustable distance. In this way, the volume of liquid required in the tank to make the float assembly move upward can be changed. The float valve may include a relief valve or a plug with a bleed orifice to permit vapour flow from the tank to the vapour vent line in the event that the pressure within the tank exceeds a predetermined value.

IPC Classes  ?

• F16K 31/30 - Operating meansReleasing devices actuated by fluid actuated by a float actuating a gate valve or sliding valve