Ulvac DIS-90, Instruction Manual

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4.1 Air-flush closed operation
4.1.1 Start-up
①
Check that blank flange of outlet is removed.
②
Close isolation valve in order to prevent the drawback of debris attached to the
inside of vacuum pump into vacuum chamber due to pressure differential,
resulting in vacuum break and pollution.
(Open leak valve if you use leak valve).
③
Turn on vacuum pump.
Please install an external power switch or protective device (breaker) before
letting vacuum pump operate.
④
Check start-up of vacuum pump and open isolation valve (close leak valve
soon after start-up if you use leak valve) and evacuate vacuum chamber.
Important
When continuously operating pump at around ultimate pressure (for example, using as fore line
pump of turbo molecular pump) ,
It can cause foreign matter or moisture to deposit inside pump, resulting in failure.
In that case, do air-flush opened operation or close isolation valve and open inlet to atmosphere for 3~5 seconds,
3~5 times daily.
Be careful not to damage air-flush port (especially air-muffler section).
If not, it can cause failure.
When doing air-flush opened operation,
Noise level will increase (by 7~8dB).
Install pump in an area which is not exposed to debris such as iron powder, stone powder,
polish powder or wood dust.
Debris can clog air-muffler, undercutting air-flush effect.
4.1.2 Shut-down
①
Be sure to close isolation valve in order to prevent the drawback of debris
attached to inside of vacuum pump into vacuum chamber during operation due to
pressure differential (open leak valve if you use leak valve).
②
Turn off vacuum pump.
Please install an external power switch or protective device (breaker) before
letting vacuum pump operate.
③
Check shut-down of vacuum pump.
Important
Be sure to close isolation valve between vacuum pump and vacuum chamber during pump
shut-down.
If vacuum pump stops during air-flush opened operation, atmospheric air is drawn back from air-flush port to inside
of vacuum pump, and vacuum on chamber side cannot be maintained. Be sure to close isolation valve between
vacuum pump and vacuum chamber to prevent the drawback of debris from vacuum pump into vacuum chamber
before stopping vacuum pump.
When returning air-flush opened operation to air-flush closed operation, operate as per 4.2.3[page 22].