20 Valve Materials-materials Of Valve Body, Bonnet And Disc

Publish Time: 08/26 2024 Author: Site Editor Visit: 71

Many valves can adapt to a variety of working conditions, but if the valve material is not selected properly, the performance and service life of the valve will be greatly reduced. First of all, the valve material should be selected according to the use range to make it perform well.

Lined Valve, valve cover and valve disc

The valve body, valve cover and valve disc are the main parts of the valve, directly bearing the medium pressure, and the materials used must comply with the provisions of "pressure and temperature grade of valve".

Commonly used materials are as follows:

1 Gray cast iron

Gray cast iron is suitable for water, steam, air, gas and oil with a nominal pressure of PN≤1.0MPa and a temperature of -10℃～200℃.

Common grades of gray cast iron: HT200, HT250, HT300, HT350.

2 Malleable cast iron

Suitable for water, steam, air and oil with a nominal pressure of PN≤2.5MPa and a temperature of -30～300℃.

Common grades: KTH300-06, KTH330-08, KTH350-10.

3 Ductile iron

Applicable to media such as water, steam, air and oil with PN≤4.0MPa and temperature of -30-350℃.

Common grades: QT400-15, QT450-10, QT500-7.

4 Acid-resistant high-silicon ductile iron

Applicable to corrosive media with nominal pressure PN≤0.25MPa and temperature below 120℃.

5 Carbon steel

Applicable to media such as water, steam, air, hydrogen, ammonia, nitrogen and petroleum products with nominal pressure PN≤32.0MPa and temperature of -30-425℃.

Common grades: WC1, WCB, ZG25 and professional steel 20, 25, 30 and low-alloy structural steel 16Mn.

6 Copper alloy

Applicable to water, seawater, oxygen, air, oil and other media with PN≤2.5MPa, and steam media with temperature of -40～250℃.

Common grades: ZGnSn10Zn2 (tin bronze), H62, Hpb59-1 (brass), QAZ19-2, QA19-4 (aluminum bronze).

7 High temperature copper

Applicable to steam and petroleum products with nominal pressure PN≤17.0MPa and temperature ≤570℃.

Common grades: ZGCr5Mo, 1Cr5M0, ZG20CrMoV, ZG15Gr1Mo1V, 12CrMoV, WC6, WC9 and other grades.

8 Low temperature steel

Applicable to ethylene, propylene, liquid natural gas, liquid nitrogen and other media with nominal pressure PN≤6.4Mpa and temperature ≥—196℃.

Common grades:

ZG1Cr18Ni9

0Cr18Ni9