Thaks DtiveMeNuts for the info, but is there any condition that requires us to use the rules for division 2 instead of the rules for using division 1? indeed there is a lot of information that shows comparisons between divisions 1 and 2. but I have not found definite information about when we should use division 2. Can you explain abaout this question? Thank you.
ASME VIII-1 paragraph U-1(d): It basically says that the rules of ASME VIII-1 have been formulated for vessels not exceeding 3000 psi. You may build equipment using ASME VIII-1 exceeding 3000 psi, but deviations and additions to the ASME VIII-1 rules would likely be required. The code doesn't say what deviations and additions those might be, and it is left to the engineer to make that determination.
ASME VIII-2 paragraph 1.2.2.2: It basically says that ASME VIII-3 should be considered for vessels over 10,000psi.
Generally I've always considered the various codes as follows:
[ul]
[li]ASME VIII-1 : 0psi - 3,000psi (Vessels can be built above 3000psi, but additional steps should be taken to ensure it is safe [See para. U-1(d)])[/li]
[li]ASME VIII-2 : 3,000psi - 10,000psi (Vessels can be built below 3,000psi, but it's often easier to just use ASME VIII-1. Vessels can be built above 10,000psi, but again there is a more appropriate code [See para. 1.2.2.2]).[/li]
[li]ASME VIII-3 : over 10,000psi (I'm not familiar with this code at all, but I suspect you could build vessels under 10,000psi using it. It would likely be simpler however to use either ASME VIII-1 or ASME VIII-2 under 10,000psi).[/li]
[/ul]
