Over and under pressure safety device - uses plastics plate with radial holes, sealing plate with central hole and spring

摘要

The over and under pressure safety deivce is for petrol tanks of vehicles. The tank has a filling pipe closed by a cap. A joint penetrates the tank and is joined by a pipe (14) to the safety device (15). The safety device has a tube (16) with an opening (17) ending in a flat section (18). An a almost flat plate (20) is made of plastics material and has several holes (21) spaced radially, and further ones (22) and a central hole (23). There is another sealing plate (33) with a central hole (34) and a spring (35) between it and a cupel base (28). the device releases or admits air to the tank. as may be necessary.