What are the commonly used materials for valves?

What are the commonly used materials for valves?

1、 Grey cast iron: Grey cast iron is suitable for media such as water, steam, air, gas, and oil with a nominal pressure of PN ≤ 1.0MPa and a temperature range of -10 ℃ to 200 ℃. The commonly used grades of gray cast iron are HT200, HT250, HT300, and HT350.

2、 Malleable cast iron: suitable for water, steam, air, and oil media with a nominal pressure of PN ≤ 2.5MPa and a temperature of -30-300 ℃. Common grades include KTH300-06, KTH330-08, and KTH350-10.

3、 Ductile iron: suitable for media such as water, steam, air, and oil with PN ≤ 4.0MPa and temperature ranging from -30 to 350 ℃. Common grades include QT400-15, QT450-10, and QT500-7.

Given the current level of domestic technology, factories vary greatly, and users often find it difficult to inspect. Based on experience, it is recommended to use steel valves for safety when PN ≤ 2.5MPa.

4、 Acid resistant high silicon ductile iron: suitable for corrosive media with nominal pressure PN ≤ 0.25MPa and temperature below 120 ℃.

5、 Carbon steel: suitable for media such as water, steam, air, hydrogen, ammonia, nitrogen, and petroleum products with a nominal pressure of PN ≤ 32.0MPa and a temperature of -30-425 ℃. Commonly used grades include WC1, WCB, ZG25, high-quality steel 20, 25, 30, and low alloy structural steel 16Mn.

6、 Copper alloy: suitable for water, seawater, oxygen, air, oil and other media with PN ≤ 2.5MPa, as well as steam media with temperatures ranging from -40 to 250 ℃. Commonly used grades are ZGnSn10Zn2 (tin bronze), H62, Hpb59-1 (brass), QAZ19-2, QA19-4 (aluminum bronze).

7、 High temperature copper: suitable for steam and petroleum products with nominal pressure PN ≤ 17.0MPA and temperature ≤ 570 ℃. Commonly used grades include ZGCr5Mo, 1Cr5M0. ZG20CrMoV, ZG15Gr1Mo1V, 12CrMoV, WC6, WC9, and other grades. The specific selection must be in accordance with the regulations of valve pressure and temperature specifications.