Sizes
Ø
DN
Forces in N | lbf
Torques in Nm | ft-lb
Fx
Fy
Fz
ΣF
Mx
My
Mz
ΣM
200-150-31
5
15
0
3,150 |
708
2,850 |
641
3,500 |
787
5,500 |
1,236
1,750 |
1,291
1,230 |
907
1,450 |
1,069
2,560 |
1,888
200-150-40
0
15
0
3,150 |
708
2,850 |
641
3,500 |
787
5,500 |
1,236
1,750 |
1,291
1,230 |
907
1,450 |
1,069
2,560 |
1,888
4.6.3 Suction-piping checklist
Performance curve reference
CAUTION:
Vary the capacity with the regulating valve in the discharge line. Never throttle the flow from
the suction side. This action can result in decreased performance, unexpected heat gener-
ation, and equipment damage.
Net positive suction head available (NPSH
A
) must always exceed NPSH required (NPSH
R
) as shown
on the published performance curve of the pump.
Suction-piping checks
Check
Explanation/comment
Checked
Check that the distance between the inlet
flange of the pump and the closest elbow
is at least five pipe diameters.
This minimizes the risk of cavitation in the suction
inlet of the pump due to turbulence.
See the Example sections for illustrations.
Check that elbows in general do not have
sharp bends.
See the Example sections for illustrations.
—
Check that the suction piping is one or
two sizes larger than the suction inlet of
the pump.
Install an eccentric reducer between the
pump inlet and the suction piping.
The suction piping must never have a smaller diam-
eter than the suction inlet of the pump.
See the Example sections for illustrations.
Check that the eccentric reducer at the
suction flange of the pump has the follow-
ing properties:
•
Sloping side down
•
Horizontal side at the top
See the example illustrations.
Suggested suction strainers are used.
Check that they are at least three times
the area of the suction piping.
Monitor the pressure drop across the
suction strainer.
An increased pressure drop across the
strainer of 34.5 kPa | 5 psi indicates that
the strainer should be removed and
cleaned.
After a period of time (24 hours minimum)
system flushing should be complete and
the suction strainer can be removed.
Suction strainers help to prevent debris from enter-
ing the pump.
Mesh holes with a minimum diameter of 1.6 mm |
1/16 in. are recommended.
Liquids with specific gravity less than 0.60 a pres-
sure drop across the suction strainer may be due to
ice buildup. Ice buildup can cause turbulence, low
pressure areas and pumpage vaporization.
If more than one pump operates from the
same liquid source, check that separate
suction-piping lines are used for each
pump.
This recommendation helps you to achieve a higher
pump performance and prevent vapor locking espe-
cially with specific gravity of liquid less than 0.60.
If necessary, make sure that the suction
piping includes a drain valve and that it is
correctly installed.
—
4.6 Piping checklists
Model IC, ICI, ICH, ICIH Installation, Operation, and Maintenance Manual
41
