The VAH Series are manual high vacuum gate valves developed using ULVAC's wealth of accumulated vacuum technology and experience. They enable conductance to be easily adjusted.


  • O-ring shaft seals draw little air into valves.
  • Simpler structure makes maintenance easy.
  • Use of aluminum alloy enables more lightweight design.
  • Use of link mechanism enables more compact design.
  • Low vibrations
  • Low cost


  • Evacuation system lines on vacuum equipment


Model VAH
Nominal size A (B) 100A(4B), 150A(6B)
Valve material Aluminum alloy (internal parts: mild steel, nickel plating)
Gasket material Nitryl rubber
Permitted baking temperature (ºC) <60
Operating pressure range (Pa) 105 to 10-5
Leak rate (Pa·m3/s) -9 (*1)
Permitted ambient temperature (ºC) 5 to 40
Operation type Manual
Back-pressure Supported as standard feature.
Remarks Fluororubber parts are available (option).
Note:1. This specification uses SI measurement units. Conversion to non-SI units is as follows:
1 Pa = 7.5 x 10-3 torr
2. Ensure that maximum differential pressure for valve OPEN/CLOSE operations is no more than 1000 Pa.
*1 a. Seal characteristic value in static state. Leak rate doesn't include O-ring permeation rate.
b. Air adhering to shaft may be drawn in during valve operation, increasing apparent leak rate.