Compounds
Compounds, by polymer and by extreme.
Every grade name starts with its polymer, so you always know what you are buying. Then comes the duty, in plain words: RGD for rapid gas decompression, LT for low temperature, SOUR for sour service and so on. Each grade has a datasheet with its targets or typical values, its limits and its test plan, and a record for every lot.
Heat and pressure
Hot oil, steam, sour gas and aggressive fluids: the RGD, SOUR, CHEM, HT and STM grades. Judged on heat ageing, compression set, fluid swell and gas decompression.
See HPHT grades →Cold and pressure
Subsea, arctic, hydrogen dispensing and LNG-adjacent duty: the LT, ULT and H2 grades. Judged on glass transition, TR10, low-temperature sealing tests and recovery under load.
See HPLT grades →In this line. FKM, perfluoroelastomer (FFKM) and fluorosilicone (FVMQ).
Best for. Hot oil, fuel, solvent and many chemical duties where nitrile or HNBR run out of temperature or resistance.
Watch for. Steam, amines and strong bases attack many FKM grades. Low-temperature flexibility depends heavily on the grade.
Cure. Bisphenol cure for low compression set. Peroxide cure for better steam, base and chemical resistance.
In this line. HNBR, nitrile (NBR) and carboxylated nitrile (XNBR).
Best for. Dynamic and high-pressure oilfield sealing where strength, tear and abrasion resistance matter, and temperatures stay within HNBR limits.
Watch for. Heat and fluid limits sit below FKM. Resistance to rapid gas decompression and sour fluids depends on the compound, not the polymer name.
Cure. Mostly peroxide cure with coagent. Sulfur cure is possible for lower-temperature duties.
Best for. Steam, hot water, amine inhibitors, strong bases and sour service at high temperature, where FKM fails.
Watch for. Higher compression set than FKM at some temperatures, and weaker resistance to some aromatic fluids. Stiffer at low temperature.
Cure. Peroxide cure with coagent.
Best for. Steam, hot water and condensate, phosphate-ester fluids, radiation, electrolysers, fuel cells and oil-swell packers.
Watch for. Mineral oil and fuel swell EPDM badly, so it is kept out of hydrocarbon duty unless swelling is the point.
Cure. Peroxide cure for steam, water and long life. Sulfur cure for swellable elements.
In this line. Natural rubber (NR), chloroprene (CR) and polyurethane (PU).
Best for. BOP packing units and hydro gate seals (NR and CR), pig cups, wipers and wear parts (PU), and dissolvable completion elements.
Watch for. Each has a narrow temperature and fluid window. The datasheet states it, and we will tell you when another polymer fits better.
Cure. Sulfur for NR, a metal-oxide system for CR, and polyurethane systems for PU.
Wear, chemistry and low friction, from −200 °C to 260 °C
Filled PTFE: glass, carbon, graphite, bronze and MoS2. Wear rings, back-up rings, seats, bearings and gaskets, where rubber cannot take the chemistry or the temperature. Rigid, so it is used as a ring or jacket, often with a spring.
See PTFE compounds and the filler chooser →These are general characteristics of each polymer family. A compound can sit well inside or outside them. The datasheet and your own testing decide.
Grades
Published grades
Choose a grade to see its datasheet, or start a requirement from it and change only what you need. All datasheets as PDF downloads.
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Application notes
What to specify for common duties
Short technical notes on the duties we are asked about most. Open one, then start a requirement from it.
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Reading a grade name
The name tells you the polymer first, then the duty.
Example: FKM-RGD90P-01 is a fluoroelastomer (FKM) designed for rapid gas decompression (RGD), nominal 90 Shore A, peroxide cured, recipe 01. In conversation it is simply “FKM RGD 90P”. Every part of the name is a plain description, so there is nothing to decode and nothing borrowed. A lot number adds the year, the month and a batch sequence to the grade, as in FKM-RGD90P-01-2703-001.
The duty says what a grade is designed for. The qualification plan on its datasheet says what it has passed: a test-backed duty such as RGD, LT, SOUR or H2 shows its test as planned until the report is on file.
| Part | Meaning |
|---|---|
| FKM / HNBR / EPDM | The polymer, always first, in its ASTM D1418 abbreviation: FKM, FFKM, FVMQ, HNBR, NBR, XNBR, FEPM, EPDM, NR, CR or PU. |
| RGD / LT / SOUR | The duty code: what the grade is designed for, in plain words (the full list is below). A hyphen goes before the hardness when the code ends in a digit, as in HNBR-H2-80P-01. |
| 90 | Nominal hardness in Shore A. |
| P / B / S / X | Cure: peroxide, bisphenol, sulfur, or another system (metal oxide for CR, a polyurethane system for PU). |
| -01 | Recipe number. A new number means a new recipe. A sibling grade for another job gets its own duty code, never a new recipe number. |
| PTFE-GL25-01 | Filled PTFE names carry a filler code and its weight percent instead of a duty family and hardness. See the PTFE grades. |
The duty codes
| Code | Said as | Designed for |
|---|---|---|
| RGD | RGD | Rapid gas decompression (RGD) and high-pressure sour gas |
| LT | Low-Temp | Sealing under pressure at −40 °C or below (HPLT), often in equipment that also runs hot |
| ULT | Ultra-Low-Temp | Sealing under pressure at −55 °C or below: the coldest grade in its polymer |
| HT | High-Temp | The highest temperatures and longest lives |
| SOUR | Sour | Sour service: H2S, amine inhibitors and completion chemistry |
| CHEM | Chemical | Bases, amines, high-pH fluids and steam chemistry that attack standard FKM |
| CO2 | CO2 | CO2, carbon capture and methanol service |
| STM | Steam | Steam, hot water, condensate, geothermal and thermal power plants |
| PKR | Packer | Packer elements and anti-extrusion parts |
| BOP | BOP | Blowout preventer and pressure-control elements |
| WEAR | Wear | Abrasion and wear: strippers, RCD elements, pig cups, wipers |
| ESP | ESP | ESP protector bags, bonded parts and diaphragms |
| STAT | Stator | Mud motor and progressing cavity pump stators |
| SWELL | Swell | Swellable packers and seals |
| DIS | Dissolvable | Dissolvable completion elastomers |
| H2 | H2 | Hydrogen service: compression and storage, −40 °C dispensing, electrolysers, fuel cells and the gas grid |
| TRF | Transformer | Transformers, switchgear and electrical equipment |
| EHC | EHC | Turbine control (EHC) phosphate-ester fluids and fire-resistant hydraulics |
| RAD | Radiation | Nuclear power: radiation-resistant compounds |
| GATE | Gate | Hydro gates and water infrastructure |
| GEN | General | Reference O-ring and seal grades |
Need something not on the list?
Most orders start from a requirement, not a catalogue. Tell us the properties and the fluids.