Most of us have seen a gate valve installed in piping, and 99% of the time, we want to see the valve handle in the VERTICAL-UPWARD position. However, when we need to install an “intervening valve” in the relief path, which ASME allows, we may/should see the valve handle(s) in the Horizontal or below Horizontal…...
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…...
For decades, we used Appendix M-5 in Section VIII as our design basis for having intervening/stop valves before and/or after a Pressure Relief Device (PRD). But in 2021 (amid the global pandemic), ASME published its new Section XIII, Rules for Overpressure Protection. We now use Appendix B of this new ASME section when we have a design…...
