Vacuum seals, O-rings and tip seals
Sealing is where most vacuum systems actually fail. Elastomer O-rings on KF and ISO joints are quick to make and remake and are good to about 10⁻⁸ mbar with a bake limit set by the compound; metal seals on CF flanges use a knife edge biting into a copper gasket and take a 450 °C bake into UHV. Scroll-pump tip seals are a different animal again — a wearing seal inside a running machine, with a stated service life measured in thousands of hours.
Choose the compound for the gas and the temperature, not by colour: nitrile for general duty, fluoroelastomer for higher temperature and most solvents, perfluoroelastomer where nothing else survives, and PTFE-based tip seals for oil-free scroll machines. Check the size to the correct standard, the durometer, and whether the joint is bakeable. For tip seals, buy the kit that matches the exact pump variant — dimensions differ between models that look identical from outside.
We hold Taixing-made tip seals and service kits for the common scroll pumps, elastomer and metal seals for KF, ISO and CF hardware, and can quote on a part number, a sample or a drawing.
150 models listed, with specifications and quotation within 24 h.
FAQ
Which elastomer should I use — NBR, FKM or FFKM?
NBR is the cheapest and fine for clean air and mineral oil up to about 100 °C. FKM (Viton) handles most solvents and up to roughly 200 °C and is the default for vacuum service. FFKM (Kalrez, Chemraz) is for aggressive plasma chemistry and high bake temperatures — several times the price, so use it only where FKM actually fails.
Can I reuse an O-ring after opening a flange?
On a KF or ISO joint, usually yes if it is clean, not permanently compressed and shows no cracks or swelling. On a CF joint the copper gasket is single-use and must be replaced. In either case, never reuse a seal that has seen plasma or aggressive process gas.
Do you supply seals by dimension or only by pump model?
Both. Give us the pump model and part number if you have it, or the inner diameter, cord diameter and material if you are matching a loose seal. A photo next to a ruler is usually enough to identify a standard size.
What is a tip seal and is it the same as an O-ring?
No. A tip seal is the polymer strip along the edge of a scroll pump's scroll, doing the job that oil does in a wet pump. It is a wear part with a defined replacement interval and is model-specific — it is not interchangeable with any O-ring.