The Study on the Alternative Plan for the Soft Seals of Solenoid Operated Valves

The EPDM(Ethylene-Propylene-Diene rubber) sealed SOV(Solenoid Operated Valve)'s failures had occurred several times. The EPDM has a relatively low thermal resistance which lead to the failures. The objective of the study is to present the alternative plan for the soft seals to be required to be worked without leading to the SOV's failures during a long term in the high temperature circumference. The maximum allowable temperature at continuous service, 10,000 hr, of Viton was investigated that is about 50 .deg. C higher than EPDM. The maximum allowable temperature of Kalrez was investigated that is each about 150 .deg. C and 100 .deg. C higher than EPDM and Viton. Also, it was investigated that Kalrez retains its sealing force longer due to its excellent thermal resistance, and has a relatively low compression set, as compared with fluoroelastomer types. In order to not lead to the soft sealed SOV's failures during a long term in the high temperature circumference, it is required that the system variables as the operating temperature and its exposed time should be estimated correctly, and together that the soft seals suitable much for the system variables should be selected. If the soft seals suitable much for the system variables are selected, we could lower the probabilities of the soft sealed SOV's failures, and could prolong the in-service testing duration and continue to operate the system without interruption