Can I use a Section I steam valve in a Section VIII steam application?

Yes. Section I valves have more stringent setting blowdown requirements and may be used in Section VIII steam applications since they meet all the requirements as specified in Section VIII UG-125(a) “Pressure Relief Devices,” which states pressure relief devices must be “in accordance with the requirements of UG-125 through UG-137.” In addition, UG-125(b) specifies that even unfired steam boilers MUST use a Section I pressure relief device.