Environmental Seal : A seal which uses O-rings, epoxy, molded elastomer, silicone compound, or potting compound to prevent corrosion due to moisture or vapors. (RP 14F)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}