Refuelling Coupling

A refuelling coupling has an annular fitting having a bore , bayonet lugs and slots suiting it for connection to a pressure filling nozzle. A flange , drilled with screw holes for securement to a fuel tank (not shown), extends out from the fitting . Also not shown for the sake of clarity is a tube extending own from the flange. Rods extend down from the flange to a spider , with springs bearing upwards onto the underside of a dry-break member , through which the rods extend. The rods, springs and spider are within the non-shown tube. On attaching and opening of a pressure filling nozzle to the coupling, the dry-break member is displaced resiliently inwards fuel can flow past this member and into the tank. The dry-break member has a central aperture , normally closed by a plug , which is threaded externally and carries an O-ring seal above the thread. The central aperture has a plain bore orifice and is threaded below the plain bore. Thus, when the plug is screwed in, the dry-break member is fluid tight as normal.