A good requirement saves weeks. Use this checklist when you fill in the requirement builder on this site, or when you brief any compounder.
1. The part and the job
- What is it: O-ring, V-ring, lip seal, packer element, stator, diaphragm, other?
- Static or dynamic? If dynamic: reciprocating, rotary, oscillating, speed, stroke.
- Cross-section and rough size, and the groove design if you have it.
- Expected life and the cost of a failure.
2. The environment
- Fluids, with composition. Include oil type, additives, amines, inhibitors, aromatics, water cut, CO2, H2S, steam, acids and bases, and the percentage if known.
- Temperature range, with minimum, maximum, and how long the peaks last.
- Pressure, including whether it can drop quickly in gas service.
- Environment around the seal, such as ozone, sunlight, radiation, vacuum, food or water contact.
3. The performance numbers
Use the property list in the builder. For each property choose min, max, target or range, give the value and, where it matters, the test conditions.
- Hardness and tolerance.
- Tensile strength, elongation and modulus.
- Compression set, with method, time and temperature.
- Fluid swell limits, with fluid, time and temperature.
- Low-temperature requirement, such as TR10 or a functional test.
- Any specific approvals: oil and gas qualification, drinking water, food contact, gas appliance.
4. Commercial details
- Quantity for trials and for first production, and the expected annual volume.
- Destination country and any customs or documentation needs.
- Timing: when you need samples, test data and first supply.
- Your usual test laboratory, if you have one, and who pays for third-party testing.
What happens next
On the Pascalor site, every requirement receives a reference number, and you can track it through five stages: Requirement received, Candidates proposed, Lab samples, Test data issued and Batch supply. At each stage you see the next step. We tell you what we can and cannot do, including when a requirement needs a qualification we do not hold.
Sources and further reading
- See the Testing page for the method index, and the selection guide for choosing a polymer.
About this guide. It is an original summary written from public sources and standards. It is not a copy of any standard or book, and it is not engineering advice. Confirm values against the current edition of the standard and test in your own application.