Shell & tube HX - TEMA R minimum tube wall thickness
Shell & tube HX - TEMA R minimum tube wall thickness
(OP)
Hello Everybody ,
i am new to the design of HX and i would like to ask something. We have an occasion of a S/T HX per TEMA R, minimum thickness as per API 660 is 2,11mm. the corrosion and errosion allowances i add them to the above value or i add them to the calculated value of 1,7mm?
thank you in advance
Kpap
i am new to the design of HX and i would like to ask something. We have an occasion of a S/T HX per TEMA R, minimum thickness as per API 660 is 2,11mm. the corrosion and errosion allowances i add them to the above value or i add them to the calculated value of 1,7mm?
thank you in advance
Kpap





RE: Shell & tube HX - TEMA R minimum tube wall thickness
I'm not sure where did you get the 1.7 mm calculated thickness, but if it is a code calculation, you need to add the allowances to it and select the next standard thickness available for the tube diameter you are using.
Cheers,
gr2vessels
RE: Shell & tube HX - TEMA R minimum tube wall thickness
Similar requirement is specfied in API 661 for air cooled heat exchangers. I am however failed to locate any such requirement in API 660 and ASME Sec VIII.
Just to add on to previous query, how do we confirm compliance to ASME Sec VIII or API 660 requirements when both shell and tube sides are required with corrosion allowance and CS tubes are provided without any corrosion allowance?
Cheers
Sanj
RE: Shell & tube HX - TEMA R minimum tube wall thickness
gr2vessels
RE: Shell & tube HX - TEMA R minimum tube wall thickness
It is not recommended to use very thick tubes to account for corrosion allowance in corrosive services. In case of corrosive services, better to use tubes in CRA construction.
Most of the client specs I have come across, require to report excess tube thickness available over pressure required thickness which can be considered as allowance for corrosion.
Sanj
RE: Shell & tube HX - TEMA R minimum tube wall thickness
Then compare the selected thickness to the required minimum.
sanshu1111. API 660, 7.6.1.2. Also note that deviation is allowed by agreement with the buyer. This is common in TEMA as well.
Regards,
Mike