Pump Piping - General - Armstrong Design Envelope 4302 Installation And Operating Instructions Manual

1. 2 .3 installation
The most important consideration when installing a Design
Envelope 4302 and 4382 pumping unit is to make sure the
pump is free to float with expansion and contraction of the pip-
ing. Recommended arrangements are:
• Supported from the ceiling by pipe hangers (See fig. 1.7 on
page 8)
• Pipe supported at the ceiling, with the dualArm free-stand-
ing and mounted with an Armstrong Suction Guide & Flo-
Trex valve. (See fig. 1.8 and fig. 1.9 on page 8)
• Piping supported at ceiling with additional floor mounted
supports under Armstrong Suction Guide and Flo-Trex
Valve (See fig. 1.10 on page 8)
• Floor mounted saddle supports (See fig. 1.11 on page 9)
• Where required, additional floor support may be obtained
as shown in fig. 1.12. Note that the pump must not be rig-
idly attached either to the plate or to the block. Leave a V"
(3mm) gap between pump and base. The piping must be
installed in such a manner that the pump is not used as a
pipe support.
• Do not rigidly connect the pump to a permanent base (See
fig. 1.13 on page 9) Note: if the pump must be con-
nected to a permanent base, the pump must be isolated
from the piping by flexible connectors and the base isolated
from the building structure on an inertia base.
• Do not install the unit with the shaft horizontal.
• Do not support the installed unit by the motor eye bolts
or by supports to any other part of the pump other than
stated above.
important
All Design Envelope 4302 pumps contain a tapped hole in the
motor bracket above the discharge flange for draining the well.
Pipe this drain hole to a floor drain to avoid overflow of the
cavity caused by collecting chilled water condensate or from
seal failure.
1. 2 . 4 pump piping – gener al
Never connect a pump to piping, always start piping from pump.
Use as few bends as possible and preferably long radius elbows.
Do not use flexible connectors on the suction or discharge.
Make sure piping exerts no strain on pump as this would distort
the casing and cause pump misalignment.
Design Envelope 4302 & 4382
Vertical In-line Pumping Unit
Suction and discharge pipes may be increased at pump nozzle
to suit pump capacity and particular conditions of installation.
Use eccentric reducers on suction connection.
Lay out the suction line with a continual rise towards the pump
without high points, thus eliminating possibility of air pockets
that may prevent the pump from operating.
A strainer of three or four times the area of the suction pipe,
installed in the suction line, will prevent the entrance of foreign
materials into the pump. V" (3mm) diameter perforations in
the strainer are typical.
Test suction line for air leaks before starting; this becomes es-
sential with long suction line or static lift.
Install, at pump suction, a straight pipe of a length equivalent
to 4 or 6 times its diameter; this becomes essential when han-
dling liquids above 120°f (49°c). Armstrong suction guides
may be used in place of the straight pipe run and in line strainer.
Install isolation valve in both suction and discharge lines on
flooded suction application; this valve is used mainly to isolate
the pump for inspection or repair.
Install a non-slam check valve in discharge line between pump
and isolation valve to protect pump from excessive back pres-
sure and to prevent water running back through the pump in
case of driver failure. Armstrong Flo-Trex valve may be used in
place of check valve and isolation valve on pump discharge.
caution
Discharge valve only must be used to reduce the pump flow,
not the suction valve.
Care must be taken in the suction line layout and in-
stallation, as it is usually the major source of concern
in centrifugal pump applications.
important
Do not run the pump for any length of time under very low flow
conditions or with the discharge valve closed. To do so could
cause the water in the casing to reach super heated steam con-
ditions and will cause premature failure and could cause seri-
ous and dramatic damage to the pump and surrounding area.
note:
The pumping unit is accurately aligned at the factory prior to
being shipped.
Alignment on the 4302 dualArm may be verified by assuring
an equal gap between coupling halves on both sides of the
coupling.
in sta l l at io n &
opera tin g in struct io ns
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