ASME has allowed dual PRD systems ever since I started in process safety back in 1993. These systems usually have a Rupture Disc (RD) BEFORE the Pressure Safety Valve (PSV). This is usually done to protect the more expensive and more complicated PSV from the corrosive process gases. Although I never managed a PR system…...
Processes that handle Liquified Pressurized Gases are required to have Hydrostatic Relief Valves on liquid piping where the liquid can be trapped. Much like vapor/gas phase Pressure Safety Valves, it is frowned upon when we have an intervening valve under the PSV. However, many codes today ALLOW us to install a 3-way valve below the…...
I have shared the ASME and NBIC “code” requirements for these arrangements and it has already stirred a number of debates/questions; of which the API has offered some excellent guidance on this design. (emphasis by me)… Membership Required You must be a member to access this content.View Membership LevelsAlready a member? Log in here...
I just uploaded my newest version of the SAFTENG Car Seal Program that reflects the code requirements in 2025. A client has learned they need to car seal some valves that are “intervening valves” after a PRD and before a header. The OEM commissioning the process stated they had a Car Seal Program and would…...
