Thin shim should be used under the driver feet to establish parallel alignment. (In some
instances, shims may be required under the pump feet).
6.
Alignment in one direction may alter the alignment in another. Check through each alignment pro-
cedure after making any alignment alteration.
2.4 Piping - general
1.
All piping must be supported independently of the pump. The piping should always "lineup" natu-
rally with the pump flanges. Never draw the piping into place by use of force at the flanged suc-
tion and discharge connections of the pump.
2.
The piping, both suction and discharge, should be as short and direct as possible. Avoid all un-
necessary elbows, bends and fittings, as they increase the friction losses in the piping. The size
of pipe and fittings should be carefully selected and of sufficient size to keep the friction losses as
low as practical.
3.
Piping must not be connected to the pump until the grout has thoroughly hardened and the foun-
dation bolts as well as driver and pump hold-down bolts have been tightened. See Section
2.7 Connection of piping on page 16
.
4.
When handling liquids at elevated temperatures, arrangements must be made for expansion
loops or expansion joints so that the linear expansion of the pipe will not cause the pumping unit
to be drawn out of alignment.
2.5 Install suction piping
1.
General - properly installed suction piping is of extreme importance for trouble-free centrifugal pump
operation.
a) The suction pipe should be as large or larger than the pump suction.
b) lncreasers, if used, should be eccentric and preferably at the pump suction flange, sloping side
down.
c)
A centrifugal pump should never be throttled on the suction side for capacity adjustment.
2.
Installations With Pump Above Source of Supply - Suction Lift:
a) Keep suction pipe free from air pockets.
• No portion of piping should extend above
the pump suction nozzle.
b) All joints must be air tight.
c)
The suction pipe should always be submerged into the source of supply as shown in
7: Pipe submergence and entrance calculation on page 15
d) A foot valve should only be used if necessary for priming, or, if the pump is to be used on inter-
mittent service and is required to hold its prime.
e) Suction strainers when used should have a net free area of at least three times the suction pipe
area.
3.
Installations With Pump Below Source of Supply - Suction Head or Flooded Suction:
a) A gate valve should be installed in the suction line to permit closing the line for pump inspection
and maintenance.
b) The size of the entrance from the source of supply or minimum submergence over the entrance
should be calculated from the data shown in
Figure 7: Pipe submergence and entrance calcula-
for applicable condition to prevent air from being drawn into pipe.
2.4 Piping - general
14
Model 3755 Installation, Operation, and Maintenance Manual
Содержание Goulds Pumps 3755
Страница 1: ...Installation Operation and Maintenance Manual Model 3755 ...
Страница 2: ......
