What is the material of the butterfly valve stem?

Stem material classification:
During the opening and closing of the butterfly valve, the valve stem bears the forces of tension, pressure and

torsion, and is in direct contact with the medium. At the same time, there is relative frictional movement with the packing. Therefore, the valve stem material must ensure that there is enough at the specified temperature Strength and impact toughness, a certain degree of corrosion resistance and scratch resistance, and good manufacturability. The commonly used stem materials are as follows.

1. When carbon steel is used in water and steam medium with low pressure and medium temperature not exceeding 300℃, A5 ordinary carbon steel is generally used. When used in water and steam medium with medium pressure and medium temperature not exceeding 450℃, 35 high-quality carbon steel is generally used.

2. When alloy steel is used for medium pressure and high pressure, and the medium temperature does not exceed 450 ℃ water, steam, petroleum and other media, 40Cr (chromium steel) is generally used. 38CrMoALA nitriding steel can be used when it is used in water, steam and other media with high pressure and medium temperature not exceeding 540℃. 25Cr2MoVA chromium molybdenum vanadium steel is generally used when used in high pressure steam medium with medium temperature not exceeding 570℃.

3. Stainless acid-resistant steel S is used for non-corrosive and weakly corrosive media with medium and high pressure and medium temperature not exceeding 450℃. 1Cr13, 2Cr13, 3Cr13 chromium stainless steel can be selected. When used in corrosive media, stainless acid-resistant steel such as Cr17Ni2, 1Cr18Ni9Ti, Cr18Ni12Mo2Ti, Cr18Ni12Mo3Ti, and PH15-7Mo precipitation hardening steel can be selected.

4. When heat-resistant steel is used for high-temperature valves whose medium temperature does not exceed 600℃, 4Cr10Si2Mo martensitic heat-resistant steel and 4Cr14Ni14W2Mo austenitic heat-resistant steel can be selected.

Tianjin Tanghai Valve Manufacturing Co., Ltd. is one of the largest valve stem/shaft manufacturers in China, main products are butterfly valves, check valves, gate valve and globe valves. Key words:  butterfly valve, lug type butterfly valve, wafer type butterfly valve, U-type butterfly valve, double flange butterfly valve, gate valves, check valves, globe valves, valve parts (Valve body, Valve disc, Valve shaft, Valve seat…)