Fixed and sliding saddle?

[shahdadf]

Hi friends,
how should i find the correct position of fixed and sliding saddle in heat exchangers?
thanks

 

[gr2vessels]

The heat exchanger, just like any horizontal pressure vessel, is subject to thermal expansion. Depending on your process piping arrangement and the type of exchanger you are designing and other considerations, you need to lock down one saddle with anchor bolts and allow the other saddle support to move axially with the shell growth, by not fully locking the nuts of the anchor bolts. There is no specific rulling on which saddle must be the fixed one.

gr2vessels

 

[dcasto]

To help in the decision on which end to anchor, think about the piping going in and out and how it will expand when it chages temperature. Draw the exchanger and the piping on a piece of paper, then draw it longer anf the inlet outlet piping longer and see where is the best fit. You may have to run some pipe stress analysis to see what happens to the piping in the end.

 

[shahdadf]

thanks a lot friends.
but the drain of shell side can be a determinant item for sliding side?

 

[doct9960]

shahdadf,

Ask your pipe stress engineer which saddle needs to be fixed or sliding.

Fixed saddles are usually (but not all the times) located near the pipe rack side.