Heat treatment refers to the metal hot working process in which materials are heated, insulated and cooled in solid state to obtain the expected structure and properties.
Valve is the control part in the fluid conveying system, which has the functions of cutting off, regulating, shunting, backflow prevention, pressure stabilization, shunting or overflow pressure relief.
The valves used in the fluid control system, from the simplest cut-off valve to various valves used in the extremely complicated automatic control system, have quite a variety of varieties and specifications. Valves can be used to control the flow of various fluids, such as air, water, steam, corrosive media, mud, oil, liquid metal and radioactive media. Valves are divided into cast iron valves, cast steel valves and stainless steel valves (20 1, 304, 3 16, etc. ), chromium-molybdenum steel valves, chromium-molybdenum steel valves, dual-phase steel valves, plastic valves, non-standard customized valves and other valve materials.