Standard code rule is that a vessel 15 PSI or greater in pressure falls under the ASME Code and is required to code stamped. There are additional factors but for the most part, this is the main driving force.
However, this is dependent also on state rules / regulations – Texas is a non-code state such that Texas does not require pressure vessels to be code stamped. It is our understanding that all but 2 states are code states and their rules require ASME code stamps on pressure vessels. Most customers in Texas also have their pressure vessels code stamped due to the fact that if ever a vessel was moved to another state they are covered. There is also an insurance liability risk and premium cost associated with non-code stamped pressure vessels.
BEPeterson holds an ASME certification, as such, we advise customers when designing pressure vessels if it falls under ASME code rules and requires a stamp. It is totally up to the customer to have the vessel stamped. We do have customers who do not code stamp pressure vessels even if the design pressure is greater than 15 PSI. We also fabricate pressure vessels from piping which could fall under aspects of B31.1 and B31.3 piping codes – these pressure vessels are built as per ASME code but not stamped.
When a vessel is code stamped it is registered with the National Board. The U1 forms signed by an authorized ASEM code inspector (AI) are provided to the customer and are filed with the National Board. This provides both a record of documentation and also allows state agencies the ability to verify compliance.
Unless our customer requests otherwise, BEPeterson designs pressure vessels to ASME code even if the pressure vessel will not be stamped based on code rules.