(2) Will the pump perform satisfactorily in
parallel with others?
b) Curve Shape.
Evaluate the curve shape on the
basis of the following:
Does the curve need to rise continually to
the shutoff head?
(2) Is there any likelihood that the pump may be
caught in a dip in the curve, resulting in unstable operation?
(3) Motor Overload. Do not allow motor overload
at any possible operating point of the curve. Check the
operating range, shutoff condition (if applicable), and low head
Rotary, Reciprocating, and Jet Pumps. Study the
manufacturers' rating curves, and select accordingly. Provide
pump and the first shutoff valve on the discharge line.
Airlift Pumps. Use airlift pumps for low lift service
or when aeration is needed.
Selection of speed is governed by the criteria
Centrifugal Pumps .
The governing factors for
centrifugal pumps include:
DESIGN PUMP LIFE (years)
MORE THAN 10
LESS THAN 10
Maximum speed (rpm)
Operates less than 3 hpd
Operates more than 3 hpd
Rotary Pumps . Operating speeds should not exceed
those approved by the manufacturer.
Reciprocating Pumps. Operating speeds should not
exceed basic speeds prescribed in HI Hydraulic Institute