SK00-4802-DI-002-04
No.16.10.20
3
1.1.5 Leakage of high-temperature cooling water
Factor
How to avoid / Measure
High-temperature steam generated
by boiling cooling water spouts from
the inlet and outlet of the pump
cooling water due to operation
without supplying the cooling water.
(1) Provide an interlock. In the route of the system,
install a flowmeter to stop the pump when the
supply of cooling water stops.
(2) If the operation is started without supplying the
water, stop the pump and keep away from the
pump.
(3) Stop the pump and make sure that the pump
temperature becomes low. Then remove the
pump for inspection.
1.1.6
Rise of oil
Factor
How to avoid / Measure
The pump's back pressure is high
and the pumping action is lost,
causing back-flow of the oil.
Critical back pressure
ULK-04A
（
D-11
）：
40Pa
ULK-04A
（
D-31
）：
60Pa
ULK-06A
（
D-11
）：
40Pa
ULK-06A
（
D-31
）：
60Pa
ULK-10A
（
D-11
）：
35Pa
ULK-10A
（
D-31
）：
40Pa
ULK-14A
（
D-11
）：
30Pa
ULK-14A
（
D-31
）：
30Pa
An oil diffusion vacuum pump loses its pumping
action if the pump outlet pressure becomes higher
than the critical back pressure. In this case, the oil
steam spouts scattering and back-flows to the high
vacuum section.
(1) For the auxiliary pump, use one that has
sufficient pumping performance.
(2) Do not operate this unit with the outlet clogged
or with any equipment installed on the outlet
side which prevents gas from passing.
(3) Make sure that the valve for evacuation is open
before evacuation.
(4) Make sure that the back pressure and the
pressure in the high vacuum section are
sufficiently low before operating this unit.
CAUTION
WARNING
