Selection of high temperature resistant valves

When the working temperature of the valve is 425 ~ 550 ℃, it is high temperature class I (referred to as PI class). The main material of the PI grade valve is 'high temperature grade I medium carbon chromium nickel rare earth titanium high-quality heat-resistant steel' based on CF8 in the ASTMA351 standard. Because PI grade is a specific name, the concept of high temperature stainless steel (P) is included here. Therefore, if the working medium is water or steam, although high temperature steel WC6 (t≤540°C) or WC9 (t≤570°C) can also be used, and high temperature steel C5 (ZG1Cr5Mo) can also be used in the case of sulfur-containing oil, but in They cannot be called PI grades here.