Uncompromised in UHV applications

The main requirements of an angle valve in UHV applications are reliable performance, the rate of particle emission and activation, and the outgassing rate. The 28.4 UHV Angle Valve series sets the standard in these areas. The series has been designed to reduce particle emission and activation and outgassing to a minimum.

Fitted with stationary rotatable CF-flanges and bonnet metal seals the valve series is suited for bake-out temperatures up to 200°C in the manual version and up to 150°C in the pneumatically actuated version.

The 28.4 is ideal for the pumping and venting of vacuum systems. It resists high differential pressure. Tested in thousands of demanding applications under various process conditions the 28.4 series has proven its outstanding reliability in UHV applications.

Pneumatic: DN 40
Pneumatic: DN 63


Based on a reliable and robust core design the 28.4 UHV Angle Valve offers manual or pneumatic actuation in sizes from DN 16mm – 63mm (5/8” – 2½”).

The standard flange connector is CF-R, but customer specified flanges are possible. The 28.4 is sealed with a metal bonnet seal and an FKM seal at the plate although other materials for the plate seal are an option. The feedthrough is bellows sealed.

A visual position indication as well as an electrical indicator are standard. The valve can be controlled by a solenoid valve either “on board” or in a distant location if required.

In addition to these standard options, the valve can be further customized.

Key features of the 28.4 UHV Angle Valve


  • Suited to UHV applications
  • Resistance against high differential pressure
  • Long maintenance-free cycle


  • Outstanding reliability
  • Adjustable to various requirements
  • Low cost of ownership
Technical data
Sizes   DN 16 (⅝"), DN 25 (1’’) DN 40 (1½’’), DN 63 (2½’’)
Actuator Pneumatic Single acting with closirng spring (NC)
  Manual With Removable Handwheel
Body Material   Stainless Steel
Feedthrough   Bellows
Standard Flanges   CF-R
Leak Rate Valve Body < 5 × 10-10 mbar ls-1
  Valve Seat < 1 × 10-9 mbar ls-1
Pressure Range   5 × 10-10 mbar to 5 bar (abs)
Differential Pressure on the Plate In Opening Direction ≤ 2 bar
  In Closing Direction ≤ 5 bar
Differential Pressure at Opening   ≤ 1 bar
Cycles until first Service   3 Million
Temperature Valve Body ≤ 150 °C
  Pneumatic Actuator ≤ 150 °C
  Manual Actuator ≤ 120 °C
  Solenoid Valve ≤ 80 °C
  Position Indicator ≤ 80 °C
Material Valve Body DN 16, 40
                   DN 63
AISI 304 (1.4301)
AISI 316L (1.4404, 1.4435)
  Plate AISI 316L (1.4404, 1.4435)
  Bellows AISI 316L (1.4404, 1.4435)
Seal Bonnet Metal
  Gate FKM (Viton®)
Mounting Position   Any
Solenoid Valve   24 VDC (others on request)
Position Indicator: Contact Rating Voltage 5 – 50 VAC/DC
  Current 5 – 100 mA
Valve Position Indication   Visual (Mechanical)


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