SK00-4802-DI-002-04
No.16.10.20
30
For ULK-10A,ULK-14A
Drain of working fluid (See Fig. 9)
(1) After stopping the pump following Section 4.3, check that the pump and oil are at a normal
temperature again and then return the pressure in the pump to the atmospheric pressure.
(2) Prepare an aluminum foil (approx. 100 × 160) and attach it as shown in (B).
(3) Prepare a container of approx. 2L and place it under the drain.
(4) Remove the hexagon bolt
④
, remove the inspection window flange or the closure flange
②
and metal gasket
③
, and then drain the oil.
(5) Attach a new metal gasket
③
.
When attaching it, see the instructions on how to tighten the metal gasket.
How to tighten metal gasket (ConFlat type)
(1) Before attaching copper gasket, check that there are no flaws on the sealing surface.
If you get snagged on a flaw when moving your nail tip in the circumferential direction, it is
harmful to air tightness.
(2) Wipe the sealing surfaces of the flange and the gasket well with alcohol.
(3) Before tightening, apply a molybdenum disulfide lubricant to all the bolt screw parts.
(4) Tighten the four bolts by hand to fix the gasket.
(5) Fully tighten the remaining bolts.
(6) Additionally tighten all tightening bolts in order in in a crisscross and symmetrical pattern
using a torque wrench to an even torque.
Apply the torque according to the process below.
1st: Tightening torque of 5N
･
m
2nd: Tightening torque of 10N
・
m
3rd: Tightening torque of 12N
・
m
4th: Tightening torque of 12N
・
m
(7) If the leakage does not stop even after they are tightened to a torque of 12N
･
m, additionally
tighten them to 15 N
･
m.
If the leakage does not stop yet, remove the flange and check the sealing part.
A gasket once tightened is not allowed to reuse. When the flange is removed, replace the
gasket with new one.
The major causes of incomplete sealing are listed as follows:
1) There are flaws on the sealing surface.
2) Cracks on the gasket or contamination
