This style of seal is the most commonly used in the industry. They utilize continuous coil springs that are scaled to the specific sealing requirement and then integrally bonded to the elastomer during the molding process. This eliminates extrusion gaps and weak points around the circumference of the seal and solves problems associated with explosive decompression damage and chemical swell of the seal during use. “S” seals are designed to be used on all wellhead equipment with machined surfaces up to 15,000 PSI.
Sentry proprietary elastomeric compounds are utilized on S-seals
They can be used in H2S, or CO2 service and are amine resistant
Are rated for all API material classes including HH
Are rated for temperature class L-U (-50⁰ F to 250⁰ F)
Have been performance qualified for API 6A, PR-2, Appendix F