Special EPDM (Ethylene Propylene Diene Monomers) solenoid valve seals are used for applications where high-pressure gases tend to be absorbed in standard rubber seals.
Solenoid valve plunger travel stroke is typically 0.020 to 0.050 in., depending on orifice size. Choosing the wrong seal material could literally shut off the valve flow. Notice the swelling in the seal at right.
When gas is absorbed into a rubber solenoid valve seal, it doesn’t normally cause any physical degrading of properties but will cause the rubber to display a phenomenon called explosive decompression. If the system were to be vented or pressure reduced, gas that is trapped inside the rubber tends to cause the seal to balloon and swell, sometimes actually fracturing. Users in the fire extinguisher field, for instance, find that rubber swelling over a period of time may actually cause the fire extinguisher valve to shut off.
Used in place of conventional seal materials, such as urethanes, EPDM is more suitable for specific, hard-to-fill applications such as high-pressure gases used in aerospace projects.
For further information, write:
Peter Paul Electronics Co., Inc.
480 John Downey Dr.
PO Box 1180
New Britain, CT 06050-1180
Phone: 860 229-4884
Fax: 860 223-1734