Thrush 3500 RPM - Manual (Page 2)

MOUNTING
The pump unit should be set on the foundation, being careful not to damage the threads on the
foundation bolts. The flexible coupling halves should be disconnected. Shims could be inserted
and the pump leveled. A spirit level should be used on the faces of the flexible coupling halves
and on the suction and discharge flanges. If the pump has threaded nozzles, a short piece of
pipe inserted in the nozzles will serve as a smooth surface for a leveling reference point. The
shims should be adjusted until the pump is leveled horizontally and vertically. Tighten the
foundation bolts finger tight.
GROUTING
Grouting the base plate prevents lateral movement of the base plate and improves the vibration
absorbing characteristics of the foundation by increasing its mass. A wooden dam should be
constructed around the base plate to contain the grout while it is being poured. The entire base
plate should be filled with grout, allow 48 to 72 hours for grout to dry. After grout is thoroughly
dried, firmly tighten foundation bolts.
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 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 the liquid unevenly in the impeller eye and may cause a
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.
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.
Expansion joints are used primarily to prevent the transmission of piping strain, caused by
thermal expansion and contraction, piping misalignment, pressure changes, or other causes, to
the pump casing. They are also used to suppress any noise that may be transmitted through the
piping.
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.