Dear Stress Experts,

I am working on the design of one pump skid. As a part of stress analysis of this skid, I qualified the piping for Code stress ratio’s. For operating load conditions induced loads at pump nozzle are within the manufacturer’s allowable limit and found to be acceptable. Seismic analysis is done considering conservative GH and GV values. Even nozzle loads at seismic condition are found to be within the Allowable limit given by vendor.

This pump skid is expected to be shipped to different parts of the world thru road and sea. I am required to complete the shipping load analysis. For which i am considering 2.5G as acceleration factors in my pipe stress model [Similar to GH and GV values we use for Seismic analysis] as a starting point. With this assumption i am not being able to qualify the nozzle loads for shipping condition. Request you to help me with the answers for few of my questions below.

1] Does any part of the B31.3 or B31.1 or any piping code explicitly talks about the factor which is required to be considered in the piping analysis for qualifying the system for shipping load.

2] Is there any reference or any best practice to perform the shipping load analysis for any piping skid?

3] Is there any specific instructions or guidance for the pump design in the relevant API standards for shipping load?

4] Does the consideration 2.5G is on the higher side and more conservative to simulate the Shipping analysis? If so what would be the appropriate value to use

Thanks you so much for your response in advance

something to read at the beginning:

http://www.containerhandbuch.de/chb_e/stra/index.html?/chb_e/stra/stra_02_03_03.html

Your 2.5g is not realistic. Who gives you this value?

You should know the type of ship and classification society of the ship (DNV, BV, ABS, LR.....). Then based on this the acceleration is calculated

You can treat as OCC.
You can add supports as part of sea fastening in order to protect the pipes.

Regards,

Thank you so much Dan for your response. we going as per the reference you provided in the link. It is quite useful. after referring the material i found that values i considered earlier were ultra conservative and there is no need consider such a huge factors to simulate the shipping/transportation loads.