Wear behaviour of piston seals in flow meter of fuel dispenser under different pressure conditions

摘要

The main component of the flow-meter in a fuel dispenser is a piston with Polytetrafluoroethylene (PTFE) O-ring seals moving in a cylinder with stainless steel liner. So wear of PTFE seal is a key factor to determine the accuracy and the life of a flow meter. This paper reports the effect of different pressure conditions on the wear rate of the PTFE seals in a gasoline dispenser system. The pressure signals at the meter inlets were detected by pressure transducers, which were sampled and analyzed by the computer data processing system. The wear of PTFE O-ringseal was measured after the flow-meter recorded a value over one million liters. It is shown that bigger the variation in pressure higher is the wear rate of PTFE. This also leads to early failure of sealing systems. A possible explanation is also made in this paper based on the formation of PTFE transfer film on the counterface of the stainless steel.