6 Commissioning/Start-up/Shutdown
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CHTRa
6.7 Measures to be taken for shutdown
CAUTION
Off-design operating data
Damage to the pump set by cavitation!
▷
The minimum discharge head of 150 m must not be underrun, except in the
start-up and stopping phase!
▷
The minimum speed of n = 1000 rpm may only be underrun in the start-up and
stopping phase.
▷
The minimum speed (< 5 s) must be reached quickly.
WARNING
Hot surfaces - Pump and piping take on the temperature of the fluid handled.
Risk of burns!
▷
Do not touch hot surfaces.
6.7.1 Shutdown with the pump set remaining ready for operation
6.7.1.1 Pump set with electric motor
1. Close the shut-off element in the discharge line. If the discharge line is equipped
with a check valve, the shut-off element in the discharge line may remain open
as long as there is some back pressure.
2. Make sure the minimum flow valve works if applicable.
3. In the case of a pump sets with variable speed coupling:
Reduce the speed until the minimum head or minimum speed is reached.
4. Switch off the drive, making sure it runs smoothly down to a standstill.
5. Note the run-down time.
NOTE
The cooling water system remains ON.
6.7.1.2 Turbine-driven pump set with synchronised turning gear
CAUTION
Blocking of rotor
Damage to the rotor!
▷
In the event of a turning gear failure and pump standstill (n = 0 rpm), the pump
has to cool down until the pump casing temperature is ≤ 60
℃
before it is
returned to service.
▪
If the speed of the pump set drops to the speed of the turning gear, the turning
gear takes over rotating of the rotor.
▪
The pre-warming unit (if any) remains in operation.
▪
The cooling unit (if applicable) remains in operation.
6.7.1.3 Turbine-driven pump set with non-synchronised turning gear
▪
Following standstill of the pump set (n = 0 rpm) the turning gear must take over
the turning of the rotor within a period of 10 seconds..
