NW50 ISO-KF Vacuum Fitting Unit

Module Feature

NW50 is the widely adopted ISO-KF vacuum standard dimension (also called KF50), nominal inner diameter 50 mm. It belongs to the small quick-clamp vacuum flange series defined by DIN 28403 and ISO 2861. This standard covers blank flanges, straight adapters, reducing pieces, elbow tees, centering rings, elastomer / aluminum gaskets and wing-nut clamps. The clamp design enables fast assembly and disassembly without welding. Sealing is achieved by an O-ring or metal seal inside the centering ring. Wetted materials commonly include 304 / 316 stainless steel and aluminum. It supports vacuum levels down to 10⁻⁷ mbar, suitable for rough, medium and high vacuum applications. It is commonly seen on vacuum pumps, gas analyzers, leak detectors and semiconductor process chambers.

Working principle

Two NW50 flange faces are aligned with a centering ring and sealing gasket in between. The wing-nut clamp squeezes the two flanges together evenly to form a leak-tight vacuum joint. Internal vacuum pressure keeps the sealing interface engaged while the clamp maintains mechanical preload.

Onboard components

Flange body, centering ring, O-ring / metal gasket, quick clamp (optional).

LED indicators

No indicators.

Hardware self‑diagnosis

No electronic self-diagnosis; leak checking relies on external helium leak detector or vacuum gauge.

Programming software

Not applicable.

Electrical & Process Parameters

Model:NW50 Standard:ISO-KF / DIN 28403 Nominal bore:50 mm Vacuum rating:Up to 10⁻⁷ mbar Material:304SS / 316SS / Aluminum Connection type:Quick clamp Function:Leak-tight modular connection for vacuum pipelines and vacuum equipment

Mechanical & Structure

Mounting:Pipe / chamber flange connection Protection class:N/A Housing:Precision machined metal flange

Environmental

Operating temperature:-196℃ ~ +150℃ (depends on gasket material) Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:ISO 2861 compliant Status:Standard vacuum spare fitting

Installation

Clean flange faces, centering ring and gasket thoroughly. Place gasket and centering ring between two NW50 flanges. Install clamp and tighten wing nuts evenly. Perform leak test before pulling high vacuum. Avoid scratches on sealing surfaces.

Interface

NW50 flange mating face.

Diagnostic

High leak rate: Damaged O-ring, scratched sealing surface, uneven clamp tightening, foreign debris between flanges. Vacuum cannot reach target: Leak at NW50 joint or upstream component leakage.

Product Brief

NW50 ISO-KF (KF50) vacuum flange standard size, DN50 quick-clamp vacuum connection, stainless steel / aluminum construction, used for vacuum pumps, gas analyzers and semiconductor vacuum piping.