other reasonable valve known to those of skill in the art in this embodiment the one way valve 15 a is a valve disc which is held in place by a pin 52 rigid tubing 77 connecting the inlet 14 to the barrel 1 comprises a jet component 53 which defines an orifice 54 for fluid to flow into the pressure limiting means 10 and the valve means 12 an annular diaphragm 11 is clamped to the tubing 77 by a clamp ring 58 held in place by integral clips 59 the clips 59 pass through apertures 30 in the base of the tubing where the tubing meet the base of the barrel 1 these apertures 30 also provide venting to one side of the diaphragm 11 a force transfer component 55 has an outer ring or hub 18 which is in fig2 a 2 b separated from the diaphragm 11 by clearance space 31 the force transfer component 55 has multiple spokes 20 which connect the outer hub 18 to an inner portion 56 which carries a sealing washer 57 a spring 29 biases the force transfer component 55 and the sealing washer 57 against the jet 53 blocking.