Piping : Pipe Rack connection for Different Settlment of Process Section & Rack

lower the rack 10" and use a spring system

Make final connection to the plant with 6 foot long sections of flex hose rated for the duty requirements. It works great.

Hi, Thanks for the advice.. We have a line sizes from 1" to 30" sizes ( CS + SS )...

For higher sizes flexi hose may not be suitable. We are thinking of providing Slip type expansion joint..Can you advice?

A good piping designer will allw for a number of bends and expansion loops to be present in the piping runs so that the incoming piping will bend, twist and flex to suit differential movement over time. It is to that individual that the problem needs to be presented.

Bellows are good for making connections in rigid pipe flexible, though these need to be correctly supported at design stage. Beware, and please read the following story:

http://en.wikipedia.org/wiki/Flixborough_disaster

I am not sure how you can get so much different settling if you are constructing everything according to your specs. Don't you all use foundations and pack the dirt before building on it? If you are dealing with 30" pipe you may have to wait till everything settles and then refit the pipe drop from the rack to allow for the settling. I don't care much for the really big slip joints on a system that has allot of pressure or contains hazardous materials cause they tend to leak and are usually high priced. Most steam lines are designed with built in loops that give enough to compensate for the thermal expansion. On the bigger pipe sizes this is near impossible to do unless you have allot of extra room and again a bunch of money. one thing you can look into would be to use wedges and blocks to shim the under the pipe as the process structure settles and install spring hangers on the pipe rack side. If you can gradually shim the pipe up as the structure settles over a long run of pipe the induced stress may not be so great as to harm the pipe.

pipewelder

Hi,

Thanks for the advice, surely will think over it.

(As soil is having very low bearing capcity .. precess section is mounted on Raft with piling..expected settlement 3-6" for process section & Rack 1"..)

80% settlement is expected in ~3 Months after complete loading / erection & 100 % expected in 2 years of span..Just for your information

Thanks once again..

Hello,

The issue is load bearing area of the raft foundation, a correction of the load bearing area is needs to correct the disparity of settling vice versa.