## Step 1 – Define Operating Envelope
| Parameter | Questions to Answer | Impact on Selection |
| — | — | — |
| Media & contaminants | Fuels, solvents, acids, cleaning agents, gases | Determines chemical resistance; may require specialty grades |
| Temperature extremes | Cold start, steady state, upset peaks | Eliminates materials with insufficient thermal range |
| Pressure & motion | Static vs. dynamic, differential pressure, speed | Influences hardness, backup rings, or thermoplastic choices |
| Environment | UV, ozone, vacuum, radiation | May require EPDM, FKM, FFKM, or fluoropolymer components |
| Compliance | FDA, USP, NSF, ATEX, oxygen service | Narrows material list to approved compounds |

## Step 2 – Shortlist Material Families
– **NBR / HNBR** for petroleum-based fluids and moderate temperature.
– **FKM / FFKM** for aggressive chemicals, high temperature, or vacuum service.
– **EPDM** for water/steam and outdoor weathering.
– **Silicone / FVMQ** for extreme temperature cycling, medical, or food applications.
– **PTFE / PEEK / UHMWPE** for high-velocity, high-pressure, or chemically aggressive environments beyond elastomer capability.

## Step 3 – Validate With Testing
– Immersion testing (ASTM D471/ISO 1817) in real fluids at operating temperature.
– Compression set and stress relaxation (ASTM D395) to ensure sealing force retention.
– Dynamic wear/friction testing for reciprocating or rotary applications.
– Pressure burst or blow-out tests for safety-critical flanges.
– Ageing and sterilisation simulations (steam, radiation, CIP/SIP) as required.

## Step 4 – Consider Manufacturing & Supply Chain
– Availability of custom compounds or lead times for specialty grades.
– Tooling compatibility: can existing molds or machining setups support the selected material?
– Regrind/reuse policies and scrap management.
– Minimum order quantities and stocking programs to protect service parts.

## Step 5 – Document & Monitor
– Create a material specification sheet outlining composition, hardness, supplier, and qualification tests.
– Capture cross-reference numbers for alternate brands to mitigate supply risk.
– Monitor field performance and feed lessons learned back into selection criteria.

## Tools & Resources

Ready to lock in a material? Share operating media, temperature profile, pressure, and compliance requirements via the [custom quote form](/quote/custom/)—our team will provide a detailed recommendation and validation plan.