Elastomer Technology

Chemical resistance - Vermilion and legacy materials

Many chemical species cause degradation to elastomeric compounds, either by attacking the polymer or some of its compounding ingredients.

Chemical resistance

Such degradation is often highly dependent on exposure temperature, in terms of both the reaction initiating in the first place, and then the rate at which the reaction proceeds.

Sour (H2S)
Hydrogen sulphide, H2S is present in oilfield media in quantities from a few ppm to high percentages but its effects on elastomeric materials are highly temperature dependent.

The resistance of our materials to sour media is assessed through undergoing the industry-recognised Norsok M-710 test regime. This provides a solid indication of a material’s response to exposure to H2S and through measuring the effects over differing time periods across a range of concentrations it is possible to generate a predicted life expectancy using the Arrhenius model.

Whilst such figures are not necessarily representative of an operational life, they do allow meaningful comparison of ‘sour’ resistance across different materials.

Although some materials are shown to have excellent resistance to H2S this is always dependent on other application parameters and often at the expense of performance in other areas. For this reason it is always advisable to consult our Technical Support Team.

Carbon Dioxide (CO2 )
COis a small molecule and will readily diffuse into elastomers. During depressurisation, COabsorbed into a seal will generate large volumes of gas during the reverse transition.

It is for this reason that COis so aggressive towards elastomeric seals and because of this James Walker has invested in an extensive test programme to evaluate performance and develop materials suitable for this environment.

The use of Methanol is important and extensive in the Oil and Gas industry in applications such as hydrate inhibitors, drying pipelines or as a chemical solvent.

Methanol can cause excessive volume swell in elastomeric seals but to combat this James Walker has specifically formulated materials in the Vermilion range that have excellent methanol compatibility - greatly extending their use within oil and gas applications.

Vermillion SixVermilion Six
Chemical and RGD

Capability confirmed down to -15°C (+5°F) in product configured testing.

Vermilion Six is a next generation enhanced performance development of James Walker’s AF 69/90 material.

With typical characteristics of outstanding heat, amine, acid, H2S and hot water resistance, this Aflas material also provides good levels of resistance to rapid gas decompression (RGD).


  • Norsok M-710 Annex A
  • Norsok M-710 Annex B

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AF 69/90AF 69/90
Chemical resistance

Capability confirmed down -15°C (+5°F) in product configured testing.

AF 69/90 is a robust Aflas based synthetic rubber with excellent resistance to steam, amines, bases, methanol and hydrogen sulphide plus oils and lubricants.

AF 69/90 is a first generation material regarded as a benchmark material of its type for many critical oil and gas applications.


  • Norsok M-710 Annex A

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Elast-O-Lion 101Elast-O-Lion 101
Chemical and sour resistance

Capability confirmed down to -33°C (-27°F) in product configured testing.

An excellent cost-effective general purpose hydrogenated nitrile material (HNBR) providing excellent resistance to rapid gas decompression and abrasion.

Elast-O-Lion 101 is a first generation material developed over 35 years ago and still regarded as a benchmark material for many critical oil and gas applications.


  • Norsok M-710 Annex B
  • Total GS EP PVV 154/155

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