2026-05-18 <<
1. Grey cast iron
Grey cast iron valves are widely used in various industrial fields due to their low cost and broad applicability. They are commonly employed in environments where water, steam, oil, and gas serve as the medium, and are extensively applied in chemical engineering, printing and dyeing, oil and chemical industries, textiles, and many other industrial products that are minimally or not affected by iron contamination. They are suitable for low-pressure valves with operating temperatures ranging from -15 to 200°C and a nominal pressure of PN ≤ 1.6 MPa.
2. Ductile iron
Ductile iron is a type of cast iron in which nodular or spherical graphite replaces the flaky graphite found in gray cast iron. This change in the internal structure of the metal results in better mechanical properties compared to ordinary gray cast iron, without compromising other properties. Therefore, valves made of ductile iron can withstand higher operating pressures than those made of gray cast iron. They are suitable for medium and low-pressure valves with operating temperatures ranging from –30 to 350℃ and a nominal pressure of PN≤4.0MPa. The applicable media include water, seawater, steam, air, gas, oil, etc.
3. Carbon steel
Initially, the development of cast steel was to meet production needs that exceeded the capabilities of cast iron and bronze valves. However, due to the overall good performance of carbon steel valves and their high resistance to stress caused by thermal expansion, impact loads, and pipeline deformation, their usage scope has been expanded, typically including operating conditions where cast iron and bronze valves are used. They are suitable for medium and high-pressure valves with operating temperatures ranging from -29 to 425°C. Among them, 16Mn and 30Mn are commonly used as substitutes for ASTM A105 when the temperature ranges from -40 to 400°C. The applicable media include saturated steam and superheated steam, as well as high-temperature and low-temperature oil products, liquefied gases, compressed air, water, natural gas, etc.
