STP-H803/H1303 Series Instruction Manual
4.3.4 Vacuum
Piping
Installation
◇
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.
◇
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.
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.
Before installing the STP pump, check whether or not there are scratches on
the surface.
2) Use stainless steel or aluminum alloy 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) It is recommended to use a backing pump of pumping speed 1300 L/min or
more.
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) Connect the STP pump and the backing pump using stainless steel or
aluminum alloy tubing, flexible tubing, vacuum rubber or Teflon tubing, and
other.
The following measures can be used to avoid the transmission of the vibration
of the backing pump to the STP pump and the vacuum equipment.
•
DO NOT place the backing pump on the same floor as the vacuum
equipment.
•
Locate the backing pump on a vibration-proof table.
Attain 1/3 or less of the rotational speed of the backing pump, when
adjusting the inherent frequency of the backing pump installed on a
vibration-proof table.
•
Attach a weight to the piping from the backing pump, or secure the piping
to a rigid, heavy object free of vibration.
•
Use a tube of high flexibility.
4-13
