KF40 Centering Ring – SS304 Inner Ring for ISO-KF Flanges, KF16 / KF25 / KF40 / KF50 (KF-CR)

KF40 Centering Ring in SS304, Also in KF16, KF25 and KF50

A KF40 centering ring is the inner metal ring of an ISO-KF quick-flange joint. Ours is CNC machined from SS304 stainless steel and made in four sizes: KF16, KF25, KF40 and KF50. The ring sits between two KF flanges, centers the bore so the two sides line up, and carries the elastomer seal in its groove. A KF clamp then pulls the two flanges onto the ring and the joint is vacuum tight, with no bolts, threads or welding.

The ring is supplied bare, without O-ring, so you fit the elastomer your process calls for. 316 stainless is made to order. The same ISO-KF flange is used on our KF vacuum valves (NW16 to NW50), so one ring size serves both the valve and the line it sits in.

Which KF Centering Ring Size Do You Need?

KF, NW and DN are three names for the same nominal size. A KF40 centering ring, an NW40 centering ring and a DN 40 ISO-KF centering ring are the same part. Match the ring to the nominal size stamped on your flange or valve.

Flange outside diameters are the ISO-KF standard values, so the ring mates with ISO-KF flanges and clamps of the same size from any maker.

主要規格

本產品係依據我們的 ISO 9001 品質系統製造。.

How a KF Centering Ring Works

ISO-KF is the small-flange standard for vacuum lines. KF stands for Kleinflansch (small flange) and NW for Nennweite; both refer to the same ISO 2861 dimensions. The two flanges in a KF joint are identical and have no bolt holes. Everything that makes the joint work sits between them: the centering ring, the seal it carries, and the clamp around the outside.

The ring does three jobs. Its stepped profile keys into each flange, so the two sides are held concentric. Its outer groove holds the elastomer seal at the right diameter. And its faces give the clamp something solid to compress the seal against. Close the clamp and the joint is made; open it and the line comes apart in seconds, which is why KF is the usual fitting on pump lines and small vacuum systems.

應用

• Roughing and foreline plumbing between vacuum pumps and chambers.
• Vacuum system piping, valves and pump ports in the KF16 to KF50 range, from rough to high vacuum service.
• Research and teaching laboratories that build and rebuild small vacuum rigs.
• Temporary test connections for leak detectors and residual gas analysers on a KF port.
• Semiconductor facility subsystems such as exhaust and abatement lines, and freeze-dryer pump connections on KF16 ports.

Need the valve as well? See the 真空閥 range, including the 氣動真空閥 以及 三通真空球閥 on KF NW40/NW50.

常見問題

Is a KF40 centering ring the same as an NW40 or DN 40 ISO-KF centering ring?

Yes. KF, NW and DN are different names for the same ISO-KF nominal size. KF40, NW40 and DN 40 ISO-KF all take the same ring, with a 55 mm flange outside diameter.

有哪些尺寸可供選擇？

KF16, KF25, KF40 and KF50, also written NW16, NW25, NW40 and NW50. State the size and quantity when you request a quote.

Does the ring come with an O-ring?

No. It is supplied as the bare stainless ring so you can fit the elastomer your process requires. Any standard ISO-KF O-ring of the same nominal size fits the groove.

What material is the ring?

SS304 stainless steel as standard. 316 stainless is made to order; tell us the size and quantity when you request a quote.

How is it made?

CNC machined from SS304 stainless steel, so the shoulder that locates in the flange bore and the groove that holds the seal are cut to size rather than pressed.

Which clamp does it need?

A standard ISO-KF clamp of the same nominal size. The ring is made to ISO-KF dimensions, so it mates with ISO-KF flanges and clamps of that size from any maker.

Does it fit your KF vacuum valves?

Yes. Our KF vacuum valves use the same ISO-KF flanges in NW16 to NW50, so the ring size that fits the valve also fits the line on either side of it.

最低訂購量是多少？

No minimum order quantity. We accept orders of any size, including small trial orders; tell us the sizes you need and we will quote them.