Common Materials and Temperature Requirements for Stainless Steel Ball Valve Housings

1. The shell material of the stainless steel ball valve: gray cast iron

Due to its low price and wide application range, gray cast iron ball valves are used in various industrial fields. They are often used in the case of water, steam, oil, gas as the medium, and are widely used in chemical, printing and dyeing, petrochemical, textile and many other industrial products that have little or no effect on iron pollution. It is suitable for low pressure valve with working temperature of -15～200℃ and nominal pressure PN≤1.6MPa.

2. The shell material of a stainless steel ball valve: black heart forged iron

It is suitable for low and medium pressure valves with working temperature of -15～300℃ and nominal pressure PN≤2.5MPa. Target media include water, seawater, gas and ammonia.

3. The shell material of a stainless steel ball valve: ductile iron

Ductile graphite is a type of cast iron that replaces the flake graphite of grey cast iron in lump or nodular graphite. This change in the internal structure of the metal improves mechanical properties without compromising other properties compared to normal grey cast iron. Therefore, the ductile iron ball valve has a higher working pressure than the gray iron valve. It is suitable for medium and low pressure valves with working temperature of -30～350℃ and nominal pressure PN≤4.0MPa. Target media include water, seawater, steam, air, gas and oil.

4. The shell material of a stainless steel ball valve: carbon steel

Cast steel was originally developed to meet production needs beyond the capacity of cast iron and bronze valves. However, carbon steel ball valves have high comprehensive performance and strong resistance to stress caused by thermal expansion, impact load and pipeline deformation, so they usually have a range of use, including the conditions of use of cast iron valves and bronze valves. It is suitable for medium and high pressure valves with a working temperature of -29~425℃. Among them, the temperature of 16Mn to 30Mn is between -40~400℃, which is often used to replace ASTMA105, and the applicable medium is saturated steam and superheated steam. Hot and cold oil, liquefied gas, compressed air, water, natural gas, etc.

5. The shell material of a stainless steel ball valve: low temperature carbon steel

Low temperature carbon steel and low nickel alloy steel can be used in the sub-zero temperature range, but cannot be extended to the low temperature region. Valves made of these materials are suitable for the following media such as seawater, carbon dioxide, acetylene, propylene and ethylene. It is suitable for low temperature valves with working temperature of -46 to 345 °C.

6. The shell material of a stainless steel ball valve: low alloy steel

Low alloy steel (such as carbon molybdenum steel, chromium molybdenum steel) valve is suitable for saturated and superheated steam, cold oil, hot oil and other working medium. It can be applied with natural gas and air. Carbon steel valves can be used up to 500°C, and low alloy steel valves can be used up to 600°C. At high temperatures, the mechanical properties of low-alloy steels are higher than those of carbon steels. It is suitable for high temperature and high pressure valve with non-corrosive medium working temperature of -29~595℃. C5 and C12 are suitable for high temperature and high pressure valves with corrosive medium operating temperature of -29~650℃.

7. The shell material of a stainless steel ball valve: austenitic stainless steel

Austenitic stainless steel contains approximately 18 chromium and 8 nickel. 18-8 austenitic stainless steel is often used for valve body and bonnet materials under high and low temperature and strong corrosion conditions. Adding molybdenum as a matrix and slightly increasing the nickel content in 18-8 stainless steel will significantly improve its corrosion resistance. Ball valves made of this steel can be widely used in the chemical industry, including conveying acetic acid, nitrates, alkalis, bleaches, food, fruit juices, carbon dioxide, tanning liquors and many other chemical products. Since austenitic stainless steels generally do not become brittle at very low temperatures, valves made from this material are well suited for low temperature operation.

8. The shell material of a stainless steel ball valve: Hastelloy

(1) Hastelloy B: This alloy contains 60 nickel, 30 molybdenum and 5 iron. Hastelloy B is particularly resistant to strong corrosion by inorganic acids, and can be used in hydrochloric acid with various concentrations of boiling point. Hastelloy B is also always suitable for ammonium chloride, zinc chloride, aluminum sulfate and ammonium sulfate. In an oxidizing atmosphere, Hastelloy B can be used up to about 800°C, and in a reducing atmosphere, the working temperature can be increased.

(2) Hastelloy C: This alloy is a nickel-based alloy containing 15 chromium and 17 molybdenum. It can be used up to 1100°C in both oxidizing and reducing atmospheres. It has excellent corrosion resistance to hydrochloric acid, sulfuric acid and phosphoric acid. And in many cases can also be used for nitric acid. Sulfur alloy C has strong corrosion resistance to various corrosive media such as chloride, hydrochloride, sulfide and oxidizing salt solution. It is also especially suitable for hydrohalic acid media such as hydrofluoric acid.