Connection To Vacuum System (Chamber) - Ulvac DIS-251 Instruction Manual

Vacuum pump turns clockwise when viewed from motor side.
Check that air comes out from outlet.
If pump turns counter-clockwise, stop vacuum pump, turn off electrical source and change 2 out of 3 cords of
electrical source connection.

3.3 Connection to vacuum system (chamber)

・ Inlet of DIS-251 is NW25 and outlet is NW16.
・ Inlet of DIS-501 is NW40 and outlet is NW25.
Danger of exhaust disruption
When connecting exhaust piping to vacuum pump and when combining piping
with another vacuum pump, pay attention to piping size and length so that it does
not cause exhaust resistance.
Exhaust resistance can disrupt air flow, resulting in failure and over-current.
Use isolation valve
Isolation valve is necessary to prevent the drawback of debris attached to the inside of vacuum pump into the
vacuum chamber during start-up and shut-down. (We recommend the use of leak valve also). We recommend the
use of an automatic valve
the drawback of debris inside pump into the vacuum chamber during power failure.
Use the clean connecting pipe between vacuum chamber and vacuum pump.
We recommend the use of a flexible tube between inlet of vacuum pump and vacuum chamber so that vibration of
pump does not transmit to vacuum chamber.
When connecting exhaust piping to outlet of vacuum pump, refer to the following size and length.
・ It is recommended in the case of DIS-251, max. 5m direct pipe length for exhaust pipe size NW16 (inner dia.16)
・ It is recommended in the case of DIS-501, max. 15m direct pipe length for exhaust pipe size NW25 (inner dia.25)
But if pipe length becomes longer, use a larger size exhaust pipe.
Make sure that exhaust piping is not clogged during pump operation.
Make sure that pressure at outlet does not exceed atmospheric pressure at any conditions.
In order to keep condensation away from feeding into the exhaust port, take proper measure.
It causes exhaust disturbance. Drain condensations periodically by using valve separately arranged.
Chamber
Isolation valve
(Automatic valve)
Important
Important
between vacuum system and inlet.
as the isolation valve which closes during power failure in order to prevent
Leak
valve
CAUTION
Vacuum pump
Inlet Outlet
DIS-251
DIS-501
-18-
Pay attention to
exhaust resistance
Outlet duct
Drain
condensation