Determining Applied Nozzle Loads on Centrifugal Pump

[pump23]

Greetings to All,

I have completed BS Mechanical this year only and joined a centrifugal pump manufacturing company. Till now our company was managing somehow for providing the "Allowable Nozzle Loads" to the customers but now I am supposed to do the same(manually), once I feel confident about that.

Since we follow ANSI standards, I have thoroughly studied ANSI/HI 9.6.2-2011. I have uedrstood the methodology and diferent changes one has to make in loads considering the temperature,
baseplate etc. but the major problem is the sign conventions used here. For sign convention, I tried to read WRC-107 also but that confused me more.

Following are my doubts(I have not uploaded any picture of pages from ANSI standard because I was affraid that might add up into breaking the copyright law.):-

1. On page no-23,(Solved example for calculating Applied nozzle loads of ASME B73.1M, B73.3M, and B73.5M)

Fy(suction) is taken as -ve (compressive) but if you take a look at page no-2, figure- 9.6.2.1.2.2- Coordinate system for ASME B73.1M, B73.3M, and B73.5M, Fz(suction) also being compressive but considered as +ve.

2. On page no-4, Table-9.6.2.1.4a, Equation no-2 why did we divide the whole equation by 2.

I have some other questions too
but they are a bit related to the
above questions only, so I dont
want to bother you much because i
think I can figure them out if the
above are solved.

Please do let me know if the
information above is not sufficient
or my questions are not clear.

Thank you in anticipation

 

[1gibson]

Don't double post.

Don't assume additional responsibilities as a pump vendor. Maybe you just need to rephrase your question, but you have no business determining "applied" loads unless maybe you are working on a test loop. "Allowable" loads sure, but not applied. If you approve a customer's pipe layout and then the pump experiences deflection due to excessive loads, you may become responsible if you approved their piping.

 

[pump23]

yeah i am sorry, I said it wrong. It was Allowable nozzle loads for pump.
We have nothing to do with piping system, All i have to do is provide the values of allwable forces and moment for pump at suction and discharge, which has to be done in accordance with ANSI/HI 9.6.2-2011, in this standard I am facing the above problem.

And I am sorry if am asking stupid questions but I am a fresher and nobody is here to guide me so I have to do it on my own.

 

[1gibson]

API 610 Annex F (11th (current) 10th, or older I think it has always been Annex F) has some good calculations for stresses due to nozzle loads. Check it out if you can get a hold of it.

 

[pump23]

Thank you for suggesting API 610, really helped a lot. I have read it and the equations used in API 610 for calculating Allowable Nozzle Loads makes sense to me but the one used in ANSI does not. Is there any other paper or standard which I can reffer to for this..???