KF Welding Flange

KF Welding Flanges provide a reliable solution for integrating ISO-KF vacuum connections into stainless steel vacuum tubes, chambers, and custom vacuum assemblies. Designed for permanent welded installation, they combine a standard KF sealing geometry with a weldable connection for vacuum piping.

Manufactured from high-quality stainless steel, these flanges offer robust construction, good weldability, and reliable performance in vacuum and high-vacuum applications.

The standardised ISO-KF (QF / NW) connection enables quick assembly and disassembly using conventional KF clamps and centring rings with O-ring seals.

Available in stainless steel 1.4301 (AISI 304) and 1.4404 (AISI 316L), with different bore diameters to accommodate various tube sizes and vacuum system requirements.

Technical Specifications

Flange Sizes: DN16, DN25, DN40, DN50 KF

Materials: Stainless Steel 1.4301 (AISI 304), Stainless Steel 1.4404 (AISI 316L)

Available Bore Diameters: 19, 20, 28, 38, 41, 44.5, 51, 54 and 57 mm

Flange Connection: ISO-KF (QF / NW)

Design: Weldable vacuum flange with central bore

Mounting: Permanent welded connection to compatible stainless steel vacuum tubing or components

Sealing: Compatible KF centring ring with elastomer O-ring seal

Applications

Suitable for manufacturing vacuum chambers, vacuum manifolds, pumping lines, laboratory vacuum equipment, and industrial vacuum systems.

KF Welding Flanges are particularly useful for custom vacuum system construction, where standard ISO-KF connections must be integrated into welded stainless steel assemblies.

Installation and Compatibility

The flange is welded to a compatible stainless steel tube or vacuum component. The appropriate bore diameter should be selected according to the tube dimensions and the intended welding configuration.

Proper welding procedures and suitable material combinations are essential to ensure a vacuum-tight connection. The completed welded assembly should be leak-tested before use.

The KF sealing surface must be protected from mechanical damage, contamination, and welding distortion during fabrication.

For connection to another ISO-KF flange, a compatible centring ring with O-ring seal and a KF clamp are required.

Compatible KF Centring Rings & Seals and KF Clamps are available separately.

The achievable vacuum pressure and operating temperature depend on the complete flange assembly, welding quality, and selected sealing c