Precautions Of Vacuum Piping - Edwards STP-iS1607 Series Instruction Manual

3.5

Precautions of vacuum piping

DO NOT open the STP pump through the flange to atmospheric air while the STP pump is
running. If atmospheric air flows into the STP pump, it may not function normally.
Install the valve to isolate cooling water (Lockout/Tagout) at your company.
Depending upon the type of the backing-pump used, atmospheric air may reverse flow into the STP
pump when the backing-pump stops.
Attach a vacuum valve to the middle of the piping between the STP pump outlet port flange and the
backing-pump, and close the vacuum valve when the backing-pump stops.
Note: Abnormal noise or excessive vibration failure (Disturbance) caused by rotor incline toward
outlet port may be generated when performing roughing vacuum depending upon pumping
speed of the backing-pump, chamber capacity, or piping length. When the failure is detected,
perform the RESET operation.
In order to let the STP pump bring its performance into full play, follow the precautions below:
1. Be careful not to scratch the flange of the STP pump and vacuum equipment. Before installing
the STP pump, check whether or not there are scratches on the surface.
2. Use steel or aluminium tubes with a low gas loss to connect the vacuum equipment to the STP
pump.
3. Take measures for minimizing leakage. It is also necessary to degrease the tubes as regularly as
possible to keep the gas loss as low as possible.
4. There is a recommended backing-pump of pumping speed. (Refer to Section 2.1, "STP pump
specifications". However, the pressure at the inlet and outlet ports varies with the flow rate of
gas, capacity of the vacuum equipment, length and material of the piping.
Select a backing-pump in accordance with the capacity and starting method (simultaneous
starting, starting after generating roughing vacuum) suitable for the vacuum equipment you use.
5. Depending upon the type of the backing-pump used, oil vapour may contaminate the inside of
the STP pump. Some oil viscosity could cause a malfunction when there is a strong reverse flow
of oil. Take the following measures to ensure the correct flow of oil:
• Attach a vacuum valve to the middle of the piping between the STP pump outlet port flange and
the backing-pump.
• Attach an absorption trap adjacent to the vacuum valve.
STP-iS1607 Series Turbomolecular Pump
CAUTION
3
MT-94E-001-C
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