The valve body, bonnet and disc are the main parts of the valve and are directly subjected to the medium pressure. The materials used must comply with the standard of “pressure and temperature rating of the valve”.
The common materials and standard as below:
NO. | Materials | Pressure | Temperature | Medium | Grades |
| 1 | Gray cast iron | ≤1.0MPa | -10 °C ~ 200 °C | water, steam, air, gas and oil | HT200, HT250, HT300, HT350 |
| 2 | Forgable cast iron | ≤ 2.5MPa | -30 ~ 300 °C | water, steam, air and oil | KTH300-06, KTH330-08, KTH350-10 |
| 3 | Ductile iron | ≤4.0MPa | -30～350°C | water, steam, air and oil | QT400—15, QT450—10, QT500—7 |
| 4 | Acid-resistant high silicon ductile iron | ≤ 0.25MPa | below 120 °C | – | – |
| 5 | Carbon steel | ≤32.0MPa | -30～425°C | water, steam, air, hydrogen, ammonia, nitrogen and petroleum products | WC1, WCB, ZG25 and high quality steel 20, 25, 30 and low alloy structural steel 16Mn. |
| 6 | Copper alloy | ≤ 2.5MPa | -40 ~ 250 °C | water, seawater, oxygen, air, oil and other media | ZGnSn10Zn2 (tin bronze), H62, Hpb59-1 (brass), QAZ19-2, QA19-4 (aluminum bronze). |
| 7 | High temperature copper | ≤17.0MPA | ≤570°C | steam and petroleum products | ZGCr5Mo, 1Cr5M0, ZG20CrMoV, ZG15Gr1Mo1V, 12CrMoV, WC6, WC9 and other grades. |
| 8 | Low temperature steel | ≤ 6.4Mpa | ≥ -196 ° C | ethylene, propylene, liquid natural gas, liquid nitrogen and other media | ZG1Cr18Ni9 0Cr18Ni9 1Cr18Ni9Ti ZG0Cr18Ni9 |
| 9 | Stainless acid resistant steel | ≤ 6.4Mpa | ≤ 200 ° C | Nitrite acid, acetic acid and other media | ZG0Cr18Ni9Ti ZG0Cr18Ni10 ZG0Cr18Ni12Mo2Ti ZG1Cr18Ni12Mo2Ti |