Material introduction of valve body, bonnet and disc

Valve body, cover and gate (disc) is one of the main parts of the valve, directly bear the pressure of the medium, the material used must meet the requirements of "valve pressure and temperature grade". Common materials are as follows:

I. gray cast iron: gray cast iron is suitable for water, steam, air, gas, oil and other media with nominal pressure PN≤ 1.0mpa and temperature between -10℃ and 200℃. Common brands of gray cast iron are: HT200, HT250, HT300, HT350.

Malleable iron: it is suitable for water, steam, air and oil media with nominal pressure PN≤2.5MPa and temperature between -30 ℃ and 300℃. The commonly used brands are: kth300-06, kth330-08, kth350-10.

Ductile iron: suitable for water, steam, air and oil media with PN≤ 4.0mpa and temperature between -30 ℃ and 350℃. Commonly used brands are: qt400-15, qt450-10, qt500-7. (in view of the current domestic technology level, each factory is uneven, users are often not easy to test. According to experience, it is recommended that PN≤2.5MPa, the valve or steel valve for safety.

Acid resistant and high silicon ductile iron: suitable for corrosive medium with nominal pressure PN≤0.25MPa and temperature lower than 120℃.

Carbon steel: suitable for water, steam, air, hydrogen, ammonia, nitrogen and petroleum products with nominal pressure PN≤32.0MPa and temperature -30 ~ 425℃. Commonly used brands are WC1, WCB, ZG25 and high quality steel 20, 25, 30 and low alloy structural steel 16Mn.

6. Copper alloy: suitable for water, sea water, oxygen, air, oil and other media with PN≤2.5MPa, as well as steam medium with temperature of -40 ~ 250℃, commonly used brand is ZGnSn10Zn2(tin bronze), H62, hpb59-1 (brass), qaz19-2, qa19-4 (aluminum bronze).

High temperature copper: suitable for steam and petroleum products whose nominal pressure PN≤ 17.0mpa and temperature ≤570℃. Commonly used brands are ZGCr5Mo,1Cr5M0. ZG20CrMoV, ZG15Gr1Mo1V, 12CrMoV, WC6, WC9, etc. Specific selection must be in accordance with the valve pressure and temperature specifications.

Low temperature steel, suitable for nominal pressure PN≤ 6.4mpa, temperature ≥ -196 ℃ ethylene, propylene, liquid natural gas, liquid nitrogen and other media, commonly used brands) ZG1Cr18Ni9, 0Cr18Ni9, 1Cr18Ni9Ti, ZG0Cr18Ni9

9, stainless acid resistant steel, suitable for nominal pressure PN≤6.4Mpa, temperature ≤200℃ nitric acid, acetic acid and other media, commonly used brands are ZG0Cr18Ni9Ti, zg0cr0cr18ni10 < nitric acid resistance >, ZG0Cr18Ni12Mo2Ti, ZG1Cr18Ni12Mo2Ti< acid resistance and urea >