Safety valve which closes on tilting of tank - has valve, biased closed, but held open by weight of ball, which rolls out of contact to release valve on tilting

摘要

A sleeve (3) is seal-fitted underneath an orifice or vent hole (2) on the upper wall (1) of the tank. At the bottom of the sleeve is a dome shaped perforated wall (5) with a central orifice (6), which is filled in the vertical position, by a heavy ball (4) which can move freely in the internal chamber (7) of the sleeve. The ball holds down, in the open position, a valve (12), the cylindrical head of which is under pressure from an internal spring (14) which abuts onto a partition wall (9). When the tank is tilted the ball rolls away from the central orifice allowing the spring to push the valve away from the partition wall and against the bevelled edges (16) of a muff (15), thus isolating the vent hole from the rest of the tank.