High Temperature Working Conditions of Valves

High Temperature Working Conditions

Valves?used for the high temperature working conditions mainly refer to the high temperature?valves?applied to the refineries.

Sub-high Temperature?

Sub-high temperatures?refer to the working temperatures of?valves?between 325℃ and 425℃. When the medium is water or steam, the valves are usually made of materials WCB, WCC, A105, WC6?and WC9. If the medium is the sour crude oil, the?valves?are supposed to be made of the materials C5, CF8, CF3, CF8M, CF3M, etc. These materials are resistant to the corrosion of the sulfide. These valves are generally used for the crude units and delayed coker units of refineries. The valves made of materials CF8, CF8M, CF3?and CF3M?are commonly used for the pipelines transporting sour crude oil, oil and natural gas instead of the acid solution. Under this working condition, the maximum working temperature of materials CF8, CF8M, CF3?and CF3M?is 450℃.

High-temperature Grade I

High-temperature Grade I?valves, also known as high-temperature PI?Grade valves, refers to the valves whose working temperatures are between 425℃?and 550℃.

The main material of the PI Grade?valve?is the top quality?high temperature GradeⅠheat-resistant steel containing?carbon,?chromium,?nickel?and?rare earth titanium, which is based on CF8 in ASTM A351 standard. PI Grade is a specific name, and the capital letter "P" represents the concept of high temperature stainless steel. Therefore, although the valves for transporting the media such as water and steam?are made of high-temperature steel?WC6(t≤540℃) or WC9(t≤570℃), and the the valves for transporting sour crude oil?are made of high-temperature steel?C5(ZG1Cr5Mo), they can not be called the PI Grade?valves.

High-temperature Grade II

When working temperatures of?valves?are between 425℃?and 650℃, the valves are called the high-temperature Grade II valves, also named the high-temperature PII Grade valves. They are mainly used for the heavy oil catalytic cracking units of refineries. High-temperature PII Grade?valves?contain the wear resistant lining high-temperature gate valves used for the three spin nozzles and other parts. The main material of the PII Grade valve is the strengthening high temperature Grade II heat-resistant steel containing carbon, chromium, nickel and rare earth titanium, which is based on CF8 in ASTM A351 standard.