Ulvac CRYO-U Series Instruction Manual page 22

bolts.
NOTE: Do not loosen all the fixed components such as the bolts, plugs, and
pressure relief valve pointed by arrows in Figure 3 before discharging the helium
gas. Ignoring this note may cause severe injury or equipment damage by flying
components due to residual pressure.
Take the following cautions when assembling the refrigerator by yourself.
1. Tighten the bolts of each part in the diagonal sequentially.
2. Because the heavy load of the high-pressure helium gas is applied, torque management
for tightening the bolts up is important. As for cylinder bolts (M5×6pcs) used in the
refrigerators of R10 to R50 series, the required torque is 6.9N･m (70kgf･cm). On the
other hand, as for cylinder bolts (M6×6pcs) used in the refrigerators of R80 series, it is
11.6N･m (118kgf･cm).
3. Fill the refrigerator with the helium gas slowly confirming that there is no defect or
abnormality.
4. When adding the helium gas, please follow the all instructions described in "8.4
Cryopump Decontamination Procedures" in this manual.
Ensure that the bolts are securely tightened. Loosened bolts or bolts tighten
under the regulation torque may cause severe injury or equipment damage.
R type Refrigerator
RM type Refrigerator
S-10
1
Self-sealing coupling
Self-sealing coupling
1
1
1
1
Self-sealing coupling
Self-sealing coupling
1
1
Presser relief valve
Figure 3 Bolt Location
ULVAC CRYOGENICS INCORPORATED
1
Cylinder bolt
1
2
1 1
Presser relief valve
2
1
Cylinder bolt
2
1
1
2
2
①：Bolts ②：Plugs
①：Bolts ②：Plugs