IOM/GK(P)/CONICAL ISSUE DATE: 10.11.2015
Page 18 LAST REV. DATE: 01.08.2019
eccentric reducers are to be fitted in suction lines and straight taper
reducers in discharge and vertical lines.
•
Misuse of reducers may cause the formation of air pockets in the pipe
and thus preventing the correct operation of the pump.
•
The suction pipe should be as short & direct as possible. Where suction
lift is not very high, it is advisable to use a foot valve. Horizontal suction
line must have a gradual rise to the pump.
•
The discharge pipe is usually preceded by a non-return valve or check
valve and a discharge gate valve. The check valve is to protect the pump
from excessive back pressure and reverse rotation of the unit and to
prevent back flow into the pump in case of stoppage or failure of the
driver. The discharge valve is used in priming, starting and when shutting
down the pump.
3.2
MOUNTING AND ALIGNMENT
A spacer type flexible coupling is used to connect pump shaft to the driver.
By using spacer type of coupling, the complete rotating unit can be removed
from the volute without removing pump casing or rotor and without
disconnecting piping connections. This also avoids any realignment of pump
and motor after re-assembly of rotating unit. However, other types of
coupling can be supplied against request.
Back pull out assembly of GK(P) pump
3.2.1 ALIGNMENT
The pump driver, if supplied, is correctly aligned on its base plate at the
factory. A certain amount of deformation of the base plate is possible during
transit and it is therefore essential to check alignment, prior to final grouting.
A flexible coupling will only compensate for small amount of misalignment
and should not be used to compensate for excessive misalignment of the
pump and driver shafts.
Inaccurate alignment results in vibration and excessive wear on the bearings,
sleeve or shaft and wear rings.
