SIPV25P, pneumatic, bellows sealed


Soft-start, pneumatically operated, in-line valves with interchangeable orifices for the controlled pumpdown of processes where turbulent flow can cause problems with particulate contamination.

Slave and master valve combination allows slow initial pumping to minimise disturbance. Both slave and master valves require separate pneumatic connections.

Features and Benefits

  • MTTF of 5000000 cycles
  • Controlled pump down to match process
  • Aluminum bodies
  • Fast acting valves in the event of power failure
  • Supplied with 5 mm, 6 mm and 7 mm interchangeable orifices
  • Bellows sealed for clean operation
  • Easy to service with replaceable orifices
  • Bakeable to 100 °C to prevent condensation of process gases


  • When the slave valve is opened gas flows at a low rate between the two sides of the valve through interchangeable orifices allowing slow pumping. Having reached a predetermined pressure level specified by the user, the master valve is opened by means of a user supplied signal allowing full bore pumping.
  • The bellows sealed valves are single acting with pneumatic opening and spring closure.
  • They are supplied with three interchangeable orifices to enable pumping characteristics to be matched to your process. A microswitch is supplied as standard to indicate valve status. Both the valve and the microswitch can be baked to 100°C to speed up degassing, and to prevent process gases from condensing inside the valve.
  • While designed primarily for the semiconductor industry the valve can also be used in other applications requiring controlled pump-down.
Technical data  
Valve actuation type Single acting, pneumatically opened, spring closed
Pressure range 1 x 10-9 to 2100 mbar
  8 x 10-10 to 1575 Torr
Maximum pressure differential  
  Opening 1000 mbar / 750 Torr
  Closing 2100 mbar / 1575 Torr
Leak rate 10-9 mbar ls- 1
  10-10 Torr ls- 1
Pneumatic connector Rp 1/8 ( 1/8 inch BSP)*
Pneumatic operating pressure 2.8 to 4.2 bar / 41 to 61 psi
Electrical indicator Single microswitch
Microswitch electrical rating 24 V, 1.5 A a.c. or d.c.
Max cycle frequency 900 h-1
Bellows reliability, MTTF 5000000 cycles
Ambient operating temperature 5 - 100 °C
Maximum baking temperature 100 °C
Construction materials HE30TF aluminum
O-ring Fluoroelastomer
Time to open/close at 4 bar (ms) SIPV25P
Slave valve 60/20
Master valve 15/41
Weight (g / oz)  
SIPV25P 920 / 32

*  With optional control valve fitted