© Edwards Limited 2011. All rights reserved.
Page 33
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Operation
A705-40-880 Issue B
4.3.3
Shut down the pump
CAUTION
If the pump is operating in an ambient temperature between -20 and -5 °C, we recommend that the pump is
never shut down, other than for maintenance. If you have any doubts about this, please contact Edwards for
advice.
CAUTION
Purge the pump before you shut it down. If you do not, process vapours may condense in the pump and corrode
or damage it.
Note:
If the pump will be shut down for a long time in an environment where the temperature is close to freezing,
we recommend that you drain the cooling-water from the pump to prevent damage to the pump: refer to
.
1. Isolate the pump-inlet from the process gases.
2. Purge the pump of contaminants. Use one of the following methods:
Operate the pump for at least 45 minutes.
Operate the pump at or close to atmospheric pressure for at least 15 minutes.
Operate the pump with full inlet purge (if fitted) for at least 15 minutes.
Operate the pump with full gas ballast (if fitted) for at least 15 minutes.
3. Switch off the pump.
4. When the pump has cooled down, turn off the cooling-water supply and the shaft-seals purge nitrogen supply.
4.4
Inspect and reset the torque limiter (pumps with a torque
limiter only)
Refer to the attached amendment for details on operation, inspection and maintenance of the torque limiter or
coupling.
Note:
If the torque limiter continually trips and decouples the pump-motor from the pump, refer to
.
WARNING
Switch off the pump and isolate the pump from the electrical supply before you reset the torque
limiter. Refit the coupling cover guard before you switch on the pump again. If you do not, there
will be a danger of injury or death from the rotating coupling mechanism.