About allowable pipe loads on a pump

THE following is my job about a pump,why the result is failed?

OUTPUT API 610 8th Edition Local Coordinates:

Suction Table 2 Force & Moment Status
Values Ratios
x distance = 0.0 mm.
y distance = 0.0 mm.
z distance = 0.0 mm.

x force = -619.0 N. 1779 0.35 Passed
y force = 564.0 N. 1423 0.40 Passed
z force = 949.0 N. 1156 0.82 Passed

x moment = -1457.0 N.m. 1329 1.10 Failed
y moment = -328.0 N.m. 678 0.48 Passed
z moment = -177.0 N.m. 1003 0.18 Passed

Check of Condition F.1.2.2 Requirement Status

FRSa/1.5FRSt2 + MRSa/1.5MRSt2 = 0.889 < or = 2.00 Passed
FRDa/1.5FRDt2 + MRDa/1.5MRDt2 = 0.000 < or = 2.00 Passed

Check of Condition F.1.2.3 Requirement Status

1.5 FRSt2 + FRDt2 = 3803. > 1266. FRCa Passed
2.0 MYSt2 + MYDt2 = 1356. > 328. MYCa Passed
1.5 MRSt2 + MRDt2 = 2705. > 1504. MRCa Passed

Overall Pump Status ** FAILED **

yuandb,
It would help to have isometric drawing or sketch of the piping. My guess is the z force is also causing the excessive x moment so that it fails to meet the allowable moment. The z force might pass, but since it is the largest force of x,y,z it would be first direction to study. Probably need to add restraint or add flexibility in the z direction.

Also, try reading the base document (API 610). It takes a ladder approach towards allowable loadings, i.e., Eqn 1, Eqn 2, Eqn 3, etc must all individually pass various numeric limits.

In your case your X moment exceeds the allowed value, reduce the moment itself or the shear forces that create the moment by adding additional flexibility to the system or additional restraints /supports

Hi there, a couple of possibilities, if you
are thinking that the pump should pass per
Appendix F, then you need to look at the
first screen of the API input. If you are
using the 2x Table 4 loads, you need to
evaluate Suction and Discharge together (I
see only one here) and I very much doubt
that the actual distances to the centerline are
(0,0,0)-- I'm not sure if your input was
a test case or actual data.


Shannon