Pipe size range for ASME B31.3

[PetroBob]

What is the largest pipe size for which B31.3 applies?

 

[pennpiper]

I do not have access to the latest edition but I have seen 72" NPS in the past.
What size do you have on your project?

prognosis: Lead or Lag

 

[steakman911]

Holy Geez penn...that is some massive "process piping".
Wow..

 

[weldstan]

There is no real limit imposed by B31.3. I've directed repairs to refinery piping up to 60" at refineries and I have seen larger. I can vouch for the 72" size indicated by pennpiper.

 

[marty007]

Our fabrication shop built some gas ducting just this year for the sulfuric acid industry that was 80"ID per B31.3. It was for low pressure (~45psi) gas service, and included 5" thick refractory on the inside surface.

You'll often find this really big B31.3 piping on furnace discharge piping, where you have a large volume of low-density gas and pressure drop is at a premium because the whole system is driven by a fan of some sort.

Cheers,
Marty

 

[TGS4]

I have personally designed a vacuum transfer line that was 144" ID x 120' long. So, there is no defined limit in the Code itself.

 

[XL83NL]

At some stage, dont you require a very thick wal to satisfactie the D/T ratio requirements? Or am I mixing things up and does that only have to do with pipe stress analysis, and branch calcs?

 

[TGS4]

The only limits with respect to D/t are that the Appendix D formulae provide values for k and i. Outside of those limits, analysis is permitted, but there are no codified values.