Rapid Gas Decompression resistant elastomers
Rapid Gas Decompression (RGD) resistant seals and O-rings are typically used in high pressure applications encountered in the oil & gas industry.
Rapid Gas Decompression (also referred to as Explosive Decompression) is a failure mechanism of elastomer seals and O-rings that is caused by a rapid reduction in pressure of a gaseous media. Gas that has permeated into the elastomer seal expands violently when the pressure is released rapidly causing fissuring and seal failure.
Cross section of a RGD damaged O-ring
RGD O-rings & seals
RGD seals and RGD O-rings are available from PPE in a range of elastomer material types including HNBR, FEPM (Aflas®), FKM and FFKM under the brand names EnDura®, Perlast® and Perlast® ICE.
PPE’s RGD elastomer materials have been tested to the standards listed above and RGD test certificates are available to download.
PPE elastomers tested to RGD standards
The following PPE material grades have been developed for RGD resistance and are available in a range of fully molded components – see Products section.
| Material grade | Material type | Description | NACE TM0192 | NACE TM0297 | ISO 23936-2 | TOTAL GS PVV 142 |
| EnDura® A90H | FEPM | Aflas® based copolymer | Not tested | Pass* | Pass | Pass |
| EnDura® V91J | FKM | General purpose grade | Not tested | Pass | Pass | Pass |
| EnDura® V91K | FKM | Low temp grade | Not tested | Pass | Pass | Pass |
| EnDura® V91A | FKM | Ultra-low temp grade | Not tested | Pass | Pass | Pass |
| EnDura® Z95X | HNBR | General purpose grade | Pass | Pass* | Pass | Pass |
| Perlast® G92E | FFKM | Chemical res. grade | Not tested | Pass* | Pass | Pass |
| Perlast® G90LT | FFKM | Low temp grade | Not tested | Pass* | Pass | Pass |
Visit the Resources section to view/download material datasheets and test certification.
EnDura® and Perlast® are registered trademarks of Precision Polymer Engineering.
Aflas® is a registered trademark of the Asahi Glass Co. Ltd
RGD testing of elastomers
International standards for testing elastomers in RGD conditions include the following:-
- NORSOK M710 rev.3 section 7.3 annex B: “Qualification of non-metallic sealing materials and manufacturers – resistance to rapid gas decompression (RGD)” – this standard is now aligned with ISO 23936-2.
- ISO 23936-2 Section 7 and Annex B: “Petroleum, petrochemical and natural gas industries: Non-metallic materials in contact with media related to oil and gas production – Part 2: Elastomers”.
- NACE TM0192: “Evaluating Elastomeric Materials in carbon dioxide decompression environments”
- NACE TM0297: “Effects of high temperature, high pressure carbon dioxide decompression on elastomeric materials”.
- TOTAL General Specification GS PVV 142, Appendix 8: “Elastomer O-ring seals explosion decompression type testing procedure”.
| NORSOK M710 Rev.2 | ISO 23936-2* | NACE TM0192 | NACE TM0297 | TOTAL GS PVV 142 | |
|---|---|---|---|---|---|
| Specimen | ISO3601 -325 O-ring | ISO3601 -312 O-ring or larger | ISO3601 -325 O-ring | ISO3601 -325 O-ring | ISO3601 -349 or -425 O-ring |
| Constraint | 20% compression | 14.5% compression | Optimal | Optimal | 13.5% compression |
| Replication | Three | Four | Three | Nine | Three |
| Gas (%) | 90/10% CH4/CO2 | 90/10% CH4/CO2 | 100% CO2 | 100% CO2 | 80/20% CH4/CO2 |
| Temperature | 100°C | 100°C | 25°C | 120°C | 75°C |
| Pressure | 15 MPa | 15 MPa | 5.2 MPa | 7 MPa | 19 MPa |
| Initial soak period | 72 hours | 68 hours | 0 | 0 | 78 hours |
| Soak period | 24 hours | 6 and 12 hours alternating | 24 hours | 24 hours | 48 hours |
| Decompression rate | 3 MPa/min | 2 MPa/min | 5.2MPa/min | 7 MPa/min | 19 to 0 MPa in 90 secs |
| Dwell at ambient pressure | 1 hour | 1 hour | 0 | 0 | 1 hour |
| Cycles | 10 | 8 | 1 | 1 | 5 |
Resources
Browse our library of resources that provide practical insights into the world of elastomer sealing.
What is Rapid Gas Decompression (RGD)?
Material info sheets:
