Recalculate MAWP for used pressure vessel 1

[vgs1133]

Hey Guys,

I want to use an older bulk propane tank as an air receiver in an industrial compressed air system. The tank is a horizontal vessel that was built in 1947 and has a volume of 30,000 gallons. I have a NB data sheet for the vessel that indicates it was constructed from ASTM A-212 GR.B steel (Firebox 70.000). The shell material is 15/16 thick and the heads 13/16, or at least it was when built, and that Joint Efficiency was 80%. State codes (GA) require (among other things) thickness testing and new calculations for MAWP be submitted with a "State Special" Change of Use Permit Application (from propane to air). I would like to run the calculations myself to see if the tank will be usable at the pressure I need, before I pay someone thousands to submit the application.

I want to know the minimum material thickness required to get the vessel permitted for 150 PSIG or higher at ambient temperatures. The vessel had a design burst pressure of 1008 PSIG, and a U-69 Code rating of 200 PSIG at 150 degrees F.

All help will be greatly appreciated.

 

[deanc]

Thank you gr2vessels.

Also,thank you JStephen,to whom I reply that your concerns are indeed valid and chances should not be taken. Perhaps...."If in doubt-scrap it out".

However after 35 years of building,repairing,inspecting and testing I will still say that an "ancient" item can be safe for pressure. If you wish I will post a link that lists dozens of "orignal" boiler locos worldwide that are still operated on a regular basis.

I do not believe that even the large corporations wish to run to failure,as it is simply not cost effective.

In any case one must understand what they are dealing with and if not hire someone who does.

 

[metengr]

In my direct involvement with the NBIC main committee activities on this very topic, I agree completely with deanc and unclesyd on this topic.

 

[robsalv]

This is perhaps the "feistiest" engtips thread I've seen.

As seen from my other posts, I'm definitely not in the 'ageist chuck it out' camp.

JStephen does raise a good point about [engineeringless] organisational philosophy - where old systems and vessels are still in place. But that's why HAZOP's and other risk management processes are or should be in place to try and weed out old legacy systems exposing organisations to Amercian BP like catastrophes.

But nothing in JStephen's post takes away from the basic and sound point, that whilst a vessel is fit for the existing service and considered fit for the new service, there's no basis for throwing it out based solely on age. FFS considers all aspects of the vessel and whether the old design is suitable for todays conditions and design standards.

A "prudent" throwing out suggests an organisation with deep deep pockets... which is definitely not the organisation I'm a part of!


As an aside, JStephen suggested that an old vessel should be considered potentially as an old bomb... in reality, any gas containing pressure vessel of any age is infact a pneumatic bomb... but most people don't pay this a moments thought as they wander through their production facilities...

 

[TTT]

Strange advice gr2vessels, we are currently having problems accepting ASME vessels here in Australia as they dont always comply with AS1210, and vessels that do may need a welder to come from USA to repair them, very hard to find a welder here that is qualified to weld to ASME.