Model VUH- 10D VUH- 251C VUH- 401C
Connection flange (*1) FC034 FC070
Valve material Valve body, bonnet flange, bellows : Austenitic stainless steel
Gasket material Bonnet seal : Gold wire; Disk seal : Copper
Permitted baking temperature (ºC) With valve open : 250; With valve closed: 200
Operating pressure range (Pa) 105 to 10-9
Leak rate (Pa·m3/s) -11
Permitted ambient temperature (ºC) 5 to 40
Operation type Manual
Seal torque (N·m) (*2) Initial 4.9 14.7
Maximum 29.4 44.1
Bellows life 10,000 operations min.
Nose life at room temperature (reference value) (*3, *4) (300) (350) (300)
Note: This specifications uses SI measurement units. Conversion to non-SI units is as follows :1Pa = 7.5 x 10-3Torr
*1 ULVAC-standard stainless steel knife-edge metal seal flanges
*2 A torque wrench is required to tighten the valve. You will need a 45 N·m (450 kg·cm) preset torque wrench and socket with a nominal diameter of 24.
*3 The actual life will depend on a variety of indeterminate factors such as the operating environment and conditions. The valve has exceeded its service life when it can no longer be sealed with a sealing torque value between the initial and maximum values (value required increases with valve age). The valve should be replaced at this time. Note that performing bake-out may decrease valve life.
*4 To replace the nose, contact an ULVAC sales office or dealer. The VUH-10D model is welded, so the nose can't be replaced.