Thrush TV2g In-Line Centrifugal Pumps - Manual (Page 2)

PIPING
The piping practices followed will directly affect the efficiency and power consumption of the
pump. Pay particular attention to the seemingly insignificant details involved in piping for they
make the difference between a good and bad installation. BOTH THE SUCTION AND THE
DISCHARGE PIPING SHOULD BE INDEPENDENTLY SUPPORTED NEAR THE PUMP.
LIBERAL USE OF PIPE HANGERS AND SUPPORT BLOCKS WILL PREVENT EXCESSIVE
STRAIN ON THE PUMP CASING AND ON THE PIPE JOINTS. The suction diameter should be
at least the same diameter as the suction nozzle on the pump and preferably larger. Use of a
smaller diameter pipe will result in loss of head due to friction. All joints must be tight to maintain
prime on the pump.
SUCTION PIPING
Long radius elbows should be used in place of standard elbows wherever possible because of
their superior flow characteristics. Elbows should not be used at the suction nozzle, but if it is
unavoidable, long radius elbows should be used. Elbows installed in any position at the suction
nozzle have a tendency to distribute liquid unevenly in the impeller eye and may cause reduction
in capacity, create an undesirable thrust condition, or create noisy operation. Eccentric reducers
should be installed directly at the suction nozzle, with the taper at the bottom to prevent air
pockets from forming. Straight taper reducers should never be used in a horizontal suction line
because of the air pocket that is formed at the leg of the reducer and the pipe (Refer to Figure 3).
DISCHARGE PIPING
The discharge pipe diameter should be the same as, or larger than, the discharge nozzle
diameter. The size of the discharge pipe to be used is dependent upon its application.
Long radius elbows should be used in the discharge piping as well as in the suction piping to
prevent excessive head loss due to friction. Whenever possible, elbows should not be installed
directly at the discharge nozzle as the turbulence created by the elbow will affect pressure gauge
readings.
An increaser should be installed at the discharge nozzle if larger diameter discharge piping is
used. Straight taper increasers and/or reducers are satisfactory in discharge applications.
PROPER PIPING ALIGNMENT IS ESSENTIAL BEFORE CONNECTION IS MADE. PIPING
ALIGNMENT SHOULD NEVER BE ACHIEVED BY FORCE. THIS COULD PRODUCE STRAIN
ON THE PIPING AND THE PUMP CASING. PROPER SUPPORTS SHOULD BE INSTALLED
FOR THE PIPING TO KEEP ITS WEIGHT OFF THE PUMP CASING.