ASME Section VIII dIV-2

We need more information to give you a more definitive answer, such as:

• Your location
• What code year was your vessel designed/built
• You mention a "design pressure" of your vessel - do you/have you confirmed a MAWP (maximum allowable working pressure) Please see this thread for discussion: http://cr4.globalspec.com/thread/30865
• Your jurisdictional requirements (ASME, National Board, API, ..............)
• How pressure vessels are regulated in your location

(Take this statement with a grain of salt/common sense: depending on the laws in your area, you may be able to do whatever you wish.)

You must talk with your local inspector/regulator.

Calculate what is the thk required as per the code for 4000kpa. If the fabricated one has the thk, then ok. Sometimes due to the availability of plates, higher thk would have been provided than required.

Hi, Factual that 4000 kpa.g is within allowable design pressure but it doesn't you can working at that level since the maximum allowable design pressure 3500 x 1.3 = 4550 kpa.g Please check the PSV whether can accommodate the maximum allowable pressure. Understood ASME Section VIII Div.1 or 2 are accommodate re-rating design but I'm not quite sure to allow increasing the pressure since the pressure vessel unit is not only bare of vessel but it's connecting to the other measurement apparatus or equipment such pump, which most of their connection limited by pressure rating such as flange rating. Enjoy your hot coffee….