Royal Way Oilfield Technology Q&A is a practical knowledge center for oilfield sealing materials, pressure-service components, repair kits and equipment maintenance.
The current guide begins with elastomer and sealing-material selection. Future technical modules can cover hammer union systems, plug valve service, swivel joint maintenance, wireline equipment and other oil tools as the product range expands.
Explore oilfield products and technical topics
- Hammer Union Seals — compare FIG compatibility, elastomer, hardness and anti-extrusion ring options for pressure-service flowlines.
- Plug Valve Seal Kits — review replacement soft-kit materials and the valve information needed before selection.
- Swivel Joint Repair Kits — identify kit style, pressure rating, seal material and included repair components.
- AS568 O-Rings & Sealing Rings — select standard sizes by inside diameter, cross section, material and hardness.
- Request a technical recommendation — send the equipment, medium, pressure, temperature, size and required quantity.
Sealing Materials Q&A
Accurate sealing-material selection starts with the exact fluid, concentration, temperature, pressure and exposure time. The answers below are practical starting points, not blanket compatibility approvals. Compounds within the same polymer family can perform differently because of cure system, filler package and formulation.
Quick material-selection guide
| Material | Common strengths | Important limitations |
|---|---|---|
| NBR / Buna-N | Petroleum oils, mineral oils, greases, good mechanical properties and cost-effective general service | Not the first choice for strong acids, strong alkalis, ozone, weathering or sustained high-temperature service |
| HNBR / HSN | Oilfield fluids, petroleum oils, improved heat, ozone and mechanical resistance compared with standard NBR | Compatibility still depends on the exact chemical; ketones, esters and aggressive chemicals require verification |
| FKM / Viton®-type | Hydrocarbon oils and fuels, many chemicals, elevated-temperature service and low gas permeability | Standard grades are not automatically suitable for hot water, steam, strong bases, amines or very low temperatures |
| EPDM | Hot water, steam, weathering, ozone, many dilute acids and alkalis, and glycol-based fluids | Generally unsuitable for petroleum oils, hydrocarbon fuels and many mineral-oil lubricants |
| Silicone / VMQ | Wide operating-temperature capability, especially low-temperature flexibility, plus dry heat and weathering | Lower tear and abrasion resistance; fuel, oil and steam compatibility must be checked for the specific compound |
| PTFE | Very broad chemical resistance, low friction and wide temperature capability | PTFE is not an elastomer; it has limited elastic recovery and normally needs a seal design suited to PTFE |
| FFKM | Broad chemical resistance combined with high-temperature capability for severe service | High cost; the exact FFKM grade must still be matched to the chemical and temperature |
Which rubber is best for acids and alkalis?
EPDM is often the first material to evaluate for water-based dilute acids and alkalis. It also performs well in many hot-water and steam applications. However, EPDM should generally not be used with petroleum oils or hydrocarbon fuels.
FKM can be a strong choice where acids are combined with hydrocarbons or higher temperatures, but standard FKM is not universally resistant to strong alkalis, amines, hot water or steam. For extremely broad chemical exposure at elevated temperature, an application-specific FFKM grade may be considered.
The exact acid or alkali, concentration and temperature must be checked against a compound-specific compatibility chart before approval.
Which sealing material is best for high temperatures?
FKM is commonly selected for elevated-temperature oil and fuel service. Silicone is useful where dry heat and flexibility over a broad temperature range matter more than abrasion resistance. FFKM is used for severe combinations of aggressive chemicals and high temperature. PTFE can also tolerate a wide temperature range, but it behaves differently from rubber and requires the correct seal geometry.
Published temperature ranges are not interchangeable between compounds. Continuous temperature, short peaks, pressure, motion and chemical exposure all change the practical limit.
Which rubber is best for low temperatures?
Silicone normally provides the best low-temperature flexibility among common elastomers. Special low-temperature NBR, HNBR and FKM compounds are also available, but standard FKM is usually not the first choice for extreme cold. The required test is whether the compound remains flexible and maintains sealing force at the actual minimum start-up temperature.
Which rubber is best for oil and fuel?
NBR is the common economical choice for petroleum oils and greases. HNBR provides improved heat, ozone and mechanical performance for demanding oilfield service. FKM is often selected for higher-temperature oils, fuels and aggressive hydrocarbon mixtures. EPDM is generally not suitable for petroleum-based oils and fuels.
Which rubber is best for hot water and steam?
EPDM is a common starting point for hot-water and steam seals. The correct compound and cure system still matter, especially at high temperature. Standard FKM should not be assumed to be steam-compatible; specialized FKM or FFKM compounds may be required for combined steam and chemical exposure.
What should be checked for oilfield gas service?
For high-pressure gas, CO₂, H₂S or rapid decompression service, polymer type alone is not enough. Check the exact gas composition, temperature, pressure, pressure-release rate, hardness, extrusion gap and rapid-gas-decompression resistance. HNBR and FKM are common oilfield starting points, but the compound must be qualified for the actual service conditions.
What information is needed for a reliable recommendation?
- Exact fluid or gas composition and concentration
- Continuous and peak temperature
- Operating pressure and decompression rate
- Static, reciprocating or rotary movement
- Seal size, groove dimensions and extrusion gap
- Required hardness and expected service life
- Industry approvals or customer specifications
Engineering note
This guide provides general material-selection guidance. It does not replace application testing or a compound-specific chemical-compatibility review. Contact Royal Way with the operating medium, temperature, pressure and equipment details for a more accurate recommendation.