A335 for superheater coils

[fvincent]

Is it permitted to construct the superheater coils with SA-335 P22 instead of SA-213 T22, according to ASME Section 1?

The reason for that is only availability.

Thanks a lot

regards

fabio vincent

http://www.figener.com.br

 

[metengr]

It really depends on what you need for fabrication tolerances in terms of OD and wall thickness, and design concerns related to heat transfer (wall thickness).

From a material standpoint, there is no problem because both material specifications are endorsed by ASME B&PV Code (Section I). The pipe specification will have additional requirements embedded for fabrication because pipe is primarily used external to the boiler for conveying fluids, whereas, tubing is used in heat transfer applications in the boiler setting.

ASME SA 335 is a material specification for seamless pipe, while SA 213 T22 material specification is for tubing in boilers and heat exchangers. I would suggest you carefully review both specifications and compare pipe versus tube tolerances in your application.

 

[fvincent]

thanks a lot, metengr



fabio vincent

http://www.figener.com.br

 

[davefitz]

There is probably much more tube to tube variation in wall thickness with the SA 335 spec , compared to the tubing spec. Thismay affect the flow distribution beetween parallel tubes ( due to unequal ID's) , but for dry steam it is probably not a big issue.

 

[fvincent]

thanks, davefitz

fabio vincent

http://www.figener.com.br