MDX [en-US]
23
6.3
Shutdown
CAUTION
Pipe system design and pump operation should prevent damage to the pump during a scheduled or
emergency shutdown.
In the event of shutdown where a significant static discharge head exists in the system, the impeller
can begin to run back-wards as the flow reverses in the pipeline. This creates a positive torque on the
shaft so the impeller connection will not unscrew. Until the flow stops, do not close any main line valves.
A change in fluid velocity can create a negative torque on the impeller and unscrew it from the shaft.
This can damage wet end pump parts as well as bearings, seals and other components.
Under no circumstances should the pipe system be equipped with a check valve or other device that can rapidly
decelerate the flow rate.
Switch off the drive, making sure that the unit runs smoothly down to a complete stop. Variable Frequency Drive (VFD)
and other controllers must not use any braking function to slow the pump. Diesel power trains should disengage the
clutch and allow the pump to coast to a stop.
Close any auxiliary connections. Pressurized bearing lubrication systems must remain running until all rotation has
stopped. If the any part of the system uses a cooling liquid supply, turn that off only after the pump has cooled down.
Where liquid filled shaft seals are used, consult seal maintenance manual for specific shutdown procedures.
Where temperatures may drop below freezing, the pump and system must be drained or otherwise protected against
freezing.
6.3.1
Measures to be taken for Prolonged Shutdown
1
The pump remains installed - operation check run
In order to make sure that the pump is always ready for instant start-up and to prevent the formation of deposits within
the pump and the pump intake area, start up the pump set regularly once a month for a short time (approx. 5 minutes)
during prolonged shutdown periods. Prior to an operation check run ensure that there is sufficient liquid available for
operating the pump.
2
The pump is dismantled and stored
Before putting the pump into storage carry out all checks specified in Section 3.2 "Storage Requirements". It is advisable
to close the nozzles (for ex. with plastic caps or similar).
6.4
Operating Limits
WARNING
The pump / unit application limits (speed, minimum and maximum flow, head, fluid density, particle size,
temperature, pH, chloride content, etc…) as stated on the data sheet must be observed. Failure to do so may
result in power overload, excessive vibration, overheating, and/or excessive corrosion or wear. If a data sheet
is not available, contact your GIW / KSB representative.
CAUTION
Any make up water or outside water supply for the system must be installed so that the GIW pump will never be
exposed to a pressure in excess of its maximum allowable operating pressure.
6.4.1
Temperature Limits
CAUTION
Do not operate the pump at temperatures exceeding those specified on the data sheet or the nameplate unless
the written permission of the manufacturer has been obtained.
Damage resulting from disregarding this warning will not be covered by the manufacturer’s warranty.
Bearing temperatures must be observed. Excessive bearing temperature could indicate misalignment or other technical
problem.
6.4.2
Switching Frequency
To prevent high temperature increases in the motor and excessive loads on the pump, coupling, motor, seals and bearings, the
switching frequency should not exceed the following number of start-ups per hour.
Summary of Contents for GIW MDX
Page 53: ...MDX en US 53 14 Notes...
