UB USER INSTRUCTIONS ENGLISH 71569247
®
•Prevent excessive external pipe load
•Never draw piping into place by applying force to pump flange connections
•Do not mount expansion joints so that their force, due to internal pressure, acts on the pump flange
The table in 4.5.3 summarizes the maximum forces and moments allowed on horizontal shaft pump casings.
Ensure piping and fittings are flushed before use.
Typical design – flooded suction
|
| Concentric | Eccentric | Suction |
Discharge |
| conical | conical | isolating |
isolating | Non | reducer | reducer | valve |
valve | return |
|
|
|
| valve |
|
|
|
>5D
Slope up from pump suction
Note:
Ensure piping for hazardous liquids is arranged to allow pump flushing before removal of the pump.
a)The inlet pipe should be one or two sizes larger than the pump inlet bore and pipe bends should be as large a radius as possible.
b)Pipework reducers should be conical and have a maximum total angle of divergence of 15 degrees.
c)On suction lift the piping should be inclined up towards the pump inlet with eccentric reducers incorporated to prevent air locks.
d)On positive suction, the inlet piping must have a constant fall towards the pump.
e)Flow should enter the pump suction with uniform flow, to minimize noise and wear. This is particularly important on large or
f)Inlet strainers, when used, should have a net `free area' of at least three times the inlet pipe area.
g)Do not install elbows at an angle other than perpendicular to the shaft axis. Elbows parallel to the shaft axis will cause uneven flow.
h)Except in unusual circumstances strainers are not recommended in inlet piping. If considerable foreign matter is expected a screen installed at the entrance to the wet well is preferable.
i)Fitting an isolation valve will allow easier maintenance.
j)Never throttle pump on suction side and never place a valve directly on the pump inlet nozzle.
Ideally reducers should be limited to one pipe diameter change, ie 150 mm (6 in.) to 200 mm (8 in.). Must have a maximum total angle of divergence of 15 degrees.
Typical design – suction lift
Discharge |
| Concentric | Eccentric |
isolating | Non | conical | conical |
valve | return | reducer | reducer |
valve | Slope down |
>5D | from pump |
suction | |
| Long |
| radius |
| bend |
Notes:
1.S = Minimum submergence >3E.
2.Ideally reducers to be limited to one pipe diameter change, ie 150 mm (6 in.) to 200 mm (8 in.). Must have a maximum total angle of divergence of 15 degrees.
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