Two advanced elastomers developed by Trelleborg Sealing Solutions capable of withstanding extremely low temperatures have passed rigorous international industry standards.
The “convention defying” materials Isolast® XploRTM J9523 perfluoroelastomer (FFKM) and XploRTM V9T82 fluoroelastomer (FKM) are engineered to maintain excellent sealing function at very low temperatures whilst also subject to high pressure conditions. The materials – which combine these characteristics with excellent chemical compatibility – have now met the ISO 23936 standard as well as revision three of NORSOK M-710, the world leader in engineered polymer solutions has announced.
It means that oil operators contending with extreme low temperatures, such as in the North Sea or around Canada and Alaska, now have the opportunity to reduce operator costs without the need to use higher cost solutions and pre-heated equipment.
Low temperature sealing is becoming more common in oil and gas applications but standard Hydrogenated Nitrile Butadiene Rubber (HNBR) and FKM materials offer limited sealing capability below freezing when operated at high pressures. When an elastomer reaches its glass transition temperature (Tg) point its properties change from being elastic and pliable to becoming solid and brittle. As a result the elastomer is ineffective as a sealing solution and can be damaged easily.
The Tg point of an elastomer is increased under pressure. In general, the Tg value rises by approximately +2 °F / +1 °C for every 750 psi / 5 MPa increase in pressure applied. For example, a seal material with a Tg rating of -4 °F / -20 °C at atmosphere will have a Tg rating of just +32 °F / 0 °C at 15,000psi / 100MPa.
Isolast® XploRTM J9523 operating temperatures range from -40 °C to +240 °C / -40 °F to +464 °F with short excursions to 250 °C / +482 °F, while XploRTM V9T82 operates from -48°C to +200°C/-54°F to +392°F with short excursions to 210°C/+410°F. These low Tg values allow the materials to remain elastic under pressure at much lower temperatures than standard grades.
Isolast® XploRTM J9523 and XploRTM V9T82 are both designed to stand up to rapid gas decompression (RGD), are suitable for sour service conditions and have an outstanding extreme low temperature performance.
The ability of the materials to successfully function below -4 °F / -20 °C whilst under 15,000 psi / 100MPa is convention defying and a further demonstration of Trelleborg’s constant determination to push the barriers of science and continue to provide more advanced and sophisticated sealing solutions.
Andrew Longdon - UK Technical Manager at Trelleborg Sealing Solutions
In addition to wellhead applications that may be subject to high operating pressures at low temperatures, Isolast® XploRTM J9523 and XploR™ V9T82 may also be ideal for drilling and intervention equipment that is stored in subzero conditions before being deployed into high pressure scenarios.
Trelleborg Sealing Solutions will be exhibiting at Subsea Expo 2016, which takes place at Aberdeen AECC from February 3 to 5, on stand 52.