Goulds Pumps 3409 - IOM - Manual (Page 21)

3409 IOM 11/04
21
SUCTION AND DISCHARGE PIPING
!
Flange loads from the piping system, including those
from thermal expansion of the piping, must not
exceed the limits of the pump. Casing deformation
can result in contact with rotating parts which can
result in excess heat generation, sparks and
premature failure.
The introduction of pumpage into a piping system which is not
well designed or adjusted may cause strain on the pump, leading
to misalignment or even impeller rubbing. Since slight strain may
go unnoticed, final alignment should be done with the system full
and up to final temperature.
Pipe flanges should not impose any strain on the pump. This can
be checked by a dial indicator. Any strain must be corrected by
adjustments in the piping system.
When installing the pump piping, be sure to observe the following
precautions:
Piping should always be run to the pump.
Do not move the pump to pipe. This could make final alignment
impossible.
Both the suction and discharge piping should be independently
anchored near the pump and properly aligned so that no strain is
transmitted to the pump when the flange bolts are tightened. Use
pipe hangers or other supports at necessary intervals to provide
support. When expansion joints are used in the piping system they
must be installed beyond the piping supports closest to the pump.
Tie bolts and spacer sleeves should be used with expansion joints
to prevent pipe strain. Do not install expansion joints next to the
pump or in any way that would cause a strain on the pump
resulting from system pressure changes. When using rubber
expansion joints, follow the recommendations of the Technical
Handbook on Rubber Expansion Joints and Flexible Pipe
Connectors. It is usually advisable to increase the size of both
suction and discharge pipes at the pump connections to decrease
the loss of head from friction.
Install piping as straight as possible, avoiding unnecessary bends.
Where necessary, use 45° or long radius 90° fittings to decrease
friction losses.
Make sure that all piping joints are air-tight.
Where flanged joints are used, assure that inside diameters match
properly.
Remove burrs and sharp edges when making up joints.
DOWELING
Pump units may, if desired, (or required in specification) be
doweled on diagonally opposite feet. This should not be done until the unit has been run for a sufficient length of
time and alignment is within the above alignment tolerance.
Fig. 10
Fig. 11
3