Collar Bolt Requirements for Shell and Tube heat Exchangers

[mrudulv08]

Dear All,

Presently, we are going on with design checking for several U tube Heat Exchanger.

In the previous revision of the datasheet, we have asked our Contractor to Provide collar bolts to keep bundle in position with shell when the Channel is removed.

My question is how Many collar bolts shall be provided and is there any code/standard basis for deciding no. of collar bolts?

Our Client is asking for 100% collar bolts - Is is advantageous to provide 100% or it will be problematic in future looking to the leakage possibilities..

There is no Project specific requirement for providing 100% collar bolts...So contractor/vendor can not be forced for the same.

Thanks for help in Advance....

MRV

 

[gr2vessels]

There is no code recommendation for the number of collar bolts, as it is not a construction issue.
To hold the tubesheet in place, you need a minimal number, 3 or 4 collar bolts. If any pressure on the shell side, the joint will leak. However, if for any reason you need to keep the shell side pressurized during the channel removal, you need 100% collar bolts. Tensionning the bolts when re-installing the channel could be tricky.
I cannot see however, any reason to keep the shell side pressurized, hence I cannot see reason for 100% collar bolts. That said, the Client request is order for you, perhaps he knows more than he's telling you.
Cheers,
gr2vessels