Nozzel Loads

[djverder]

Hello

I am after some help regarding flange nozzel loads

I work for a pump manufacturer & have been asked to calculate the nozzel loads on the flanges we use (PN16, ANSI 150 & JIS). We use 8.8 HT zinc plated bolts to fasten them on to the pump casings.

Can anyone shed any light on this matter?

Thanks

djverder

 

[BigInch]

I think you mean you have to calculate the allowable loads on the flanges, since you can't calculate loads on the flange unless you know the piping configuration and operational conditions, right?

http://virtualpipeline.spaces.msn.com

 

[djverder]

Thats correct BigInch?

A competitor of our's has these value's listed but I want to know how they achived this (Please see attachment)

Thanks

djverder

 

[BigInch]

Max allowed forces and moments are based on the amount of stress that would be permitted in your casing material without causing pressure failure, undue warping, twisting, bending or other harmful displacements in your casing and would maintain the alignments within the limits of your design or published criteria. Never done one of those, but I bet FEM modeling would be a good way to begin.

http://virtualpipeline.spaces.msn.com

 

[sms]

The easy out is to specify 0.. Lots of equipment manufacturers try to limit the flange loading to zero, which puts the onus on piping designers to come up with supports, slides, spring cans etc to control the dynamics and thermal growth of the piping to meet that requirement.

Saves some effort on the part of the pump designer, but makes things complex for the pipe designer.

A FEM model will help, but you might also want to do some experiments. From a field perspective I have see excessive flange loading cause problems with bearings, alignment, wear rings, bolting, vibration, casing cracks.

So even if you get some good numbers as to what your pump can handle, you need to pad it with a good bit of safety factor because even if the piping designer does a good job, when the fit up is off by a few inches some fitter will pull up the pipe flage to your pump flanges with a chain fall or a large pry bar.





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[rkuhn]

if the pumps are API, you can use API610 Annex F.

 

[djverder]

Unfortunatley our pumps do not comply to API610 Annex F

 

[REFINERYPROJECTS]

Piping designer keeps stresses in the pipe wall itself within established allowable limits, and ensures that end point reaction loads do not overload connected equipment nozzles, avoiding excessive equipment nozzle loads is important in all cases, this is especially true for piping systems connected to pumps, compressors and steam turbines. Excessive piping loads in these cases can cause high machine vibration, shaft misalignment, and coupling failures.

API Standard 610, "Piping Load Limitations for Centrifugal Pumps," provides an allowable load basis for pumps purchased to this standard, and covers nozzle sizes 2" through 16" inclusively. For nozzle sizes outside this range, the pump allowable load basis must be mutually agreed to among the owner, pump manufacturer, and piping designer prior to the start of engineering.

ZUHAIR ABOL-OLA