5
Isolation Valve
Vent Valve
Fig. 6.
Fig. 4a.
Suction Lift
Fig. 4b.
Suction Head
Strainer
Foot Valve
Eccentric
Reducer
Non Return Valve
Flow Control Valve
Flow Control Valve
Non Return Valve
Isolation Valve
Eccentric
Reducer
Fig. 5.
d1
d2
C4.3- Discharge piping (Fig. 4)
A control valve should be installed in the discharge pipe, as close to the pump as possible, to regulate the
required flow and head.
If the total head of the pump exceeds 10 meters or if discharge line is of appreciable length a non return
valve should be installed between the pump and isolating valve on the discharge line to protect the pump
against water hammer and reverse flow on shut down.
C4.4- Pressure gauge connections
Pressure and vacuum gauges must be properly anchored and connected at the measuring points located
on the pump flanges
(Fig. 5)
or on the pipes close to the flanges approximately 8 mm diameter tubing with
pig tail configuration to lessen pressure fluctuation. For safety purposes isolating and vent valves should be
fitted before the gages
(Fig. 6).
C4.5- Minimum flow
If there is a possibility of the pump having to operate at zero flow (against a closed discharge valve) or near
the closed valve with almost no flow, then a minimum flow valve (or a by-pass check valve) must be installed
on the discharge nozzle or on the discharge piping right after the pump but before the flow regulating valve.
In cases where there is no such a valve operating the pump against close valve for a long time causes
considerable damage on the pump since almost all the motor power is transformed into thermal energy which
is absorbed by the pumped liquid.
d1 :
Pressure gauge (suction)
d2 :
Pressure gauge (discharge)
