The Soft-Seal is a useful option for systems which handle easy-crystallising or particle-contaminatable fluids. Small elastic parts, which are as chemically inert as TeflonTM, protect sealing surfaces from particles in the fluids, reducing leakage problems which were common with TeflonTM valves. 

Perfluor, the elastomer used for the Soft-Seal, has a stable molecular structure consisting of only fluorine, carbon and oxigen atoms. Outstanding resistance to almost all chemicals. --->Chemical Compatibility Table

Effectiveness against foreign matter

Glass beads sprinkled (dia. 40 micrometers) on the valve seat

Before

After

 
Soft-Seal Diaphragm No significant scratchs are observed.
All-Teflon Diaphragm Many small holes can be observed after opration.