Plastic Seals & Components
Plastic seals and sealing components, such as PTFE seals, back-up rings, wear rings, valve seats and gaskets, are machined from PTFE, filled PTFE, PEEK, nylon and polyurethane for chemical, temperature or pressure conditions where rubber alone isn't suitable.
What it is
Machined seals can be made in any size without moulds, ideal for special or large-diameter seals and quick replacements. PTFE seals handle aggressive chemicals and wide temperatures; PU seals handle high pressure and wear; PEEK back-up rings prevent extrusion at high pressure.
Seal profiles and material are chosen by pressure, speed, temperature and media.
Typical applications
- Hydraulic and pneumatic seals
- Back-up rings and wear rings
- Valve seats and ball seats
- Chemical pump seals
- Gaskets and flange seals
Materials & grades
- PTFE and filled PTFE
- PEEK
- Polyurethane
- Nylon and acetal
Points to consider
- Provide groove dimensions, pressure, temperature and media.
- PTFE seals often need an energiser (spring or O-ring) for low-pressure sealing.
- Back-up rings prevent O-ring extrusion at high pressure.
- Surface finish of mating parts strongly affects seal life.
Frequently asked questions
Can seals be machined in custom sizes?
Yes. Machining avoids mould costs and suits special, large or urgent seals.
When should PTFE seals be used?
For aggressive chemicals, wide temperature ranges or low friction, often with an energiser.
What is a back-up ring?
A ring, often PTFE or PEEK, placed beside an O-ring to stop it extruding into the clearance gap under high pressure.