Leak valve

This is a leak valve to introduce specified gas into vacuum equipment. The vacuum seal and the shaft seal are made of fluoro rubber (Viton).(951-7177・7178)
The vacuum seal uses an O-Ring made of fluoro rubber (Viton).(951-7190・7192)
It is suitable as an atmospheric air/specified gas introduction valve when leaking high vacuum or ultra-high vacuum equipment.



  1. For ultra-high vacuum range
    Can be used in ultra-high vacuum range of up to about 10-7Pa.
  2. High heat tolerance
    Can be baked up to 125℃.
  3. Can introduce specified gas (excluding O-Ring seal type)


Type 951-7177, 951-7178 951-7190, 951-7192
Operating vacuum range Atmospheric to 10-7Pa
Leak when valve closed 6.7×10-11Pa·m3/sec or less*1
Orifice diameter φ3.5mm φ10mm
Allowable heating
Main component material Vacuum seal material: Fluoro rubber (Viton)
Shaft seal material: Fluoro rubber (Viton) O ring
Shaft seal lubricant: High vacuum silicon grease
Valve body axis: SUS304
Valve element: Brass (Ni plating)
Handle: Phenol resin
Vacuum seal material: Fluoro rubber
(Viton) O ring
Valve body: SUS304
Valve element: SS34 (Ni plating)
Connection flange φ70ICF, NW25 flange
Weight 0.4kg 0.5kg

*1. Gas permeation of the fluoro rubber (Viton) is out of specification.

*2. Please remove the handles before baking.