PACKAGE : I Bid Document VOLUME : II - Public Health Engineering

The pumps shall be capable of reverse rotation up to 125% rated full speed of the
drive motor, due to backflow of water, without damage or loosening of threaded
components.
The first critical speed shall be away from the operating speed and in no case less
than 130% of the rated speed.
Though the specifications for flanges are mentioned elsewhere in this document, it
is contractor's responsibility to ensure that correct matching flanges are provided
with the pump.
Spare parts supplied with the pump shall be identical to respective pump
components and shall be from original manufacturer.
Pumps shall run smooth without undue noise or vibration. Noise levels and
amplitude of vibrations shall be within acceptable limits. Noise level shall be
limited to 85 db at a distance of 2 m. and amplitude of vibrations (peak to peak)
shall be within 2.5 MILS in any plane as per relevant hydraulic institutes’ standards
and IS.
Unless otherwise specified, drive unit power rating shall be the maximum of the
following requirements.
a) 15% margin over the pump shaft input power at the rated duty point.
b) Pump shaft input power required considering the overloading of the pump, if any,
assuming single pump operation in the event of tripping of one or more of the pumps
operating in parallel.
c) Maximum pump shaft input power required for operation of pump at any point on the
pump performance curve between pump shut off and pump run out condition.
The pump characteristics of the offered pump should be such that shut off head is at
least 15% more than the design head.
Pumps shall be identical and shall be suitable for parallel operation with equal load
division.
GTS : General Technical Specification. Page 148