What steel is the valve usually made of? Answer in detail!

When selecting the main components of ordinary valves, we should first consider the physical properties (temperature, pressure) and chemical properties (corrosiveness) of the working medium. At the same time, we should also know the cleanliness of the medium (whether there are solid particles). In addition, a variety of materials can meet the requirements of the valve under various working conditions. However, the most economical service life and the best performance of the valve can be obtained by selecting the valve material correctly and reasonably. There are many kinds of materials for valves, which are suitable for various working conditions. The commonly used shell materials, interior materials and sealing materials are introduced as follows. 1 The common material of the shell is 1. Gray cast iron is suitable for low-pressure valves with working temperature between-1.5 ~ 200℃ and nominal pressure p Ⅳ ≤1.6 MPa. The medium used is water, gas, etc. 2. Black-core malleable cast iron is suitable for working at-15 ~ 300℃. Medium pressure valve with nominal pressure p Ⅳ ≤ 2.5 MPa. Suitable media are water, seawater, gas, ammonia, etc. 3. Ductile iron is suitable for working at -30 ~ 350℃. The medium and low pressure valves with nominal pressure P Ⅳ ≤ 4.0 MPa are suitable for water, seawater, steam, air, gas and oil. 4. Carbon steel (WCA, WCB, WCC) is suitable for medium and high pressure valves with working temperature between -29℃ and 425℃. Medium 1 6Mn and 30Mn work at -40 ~ 450℃, and are often used to replace ASTM A 105. Suitable media are saturated steam -2 and superheated steam. High and low temperature oil, liquefied gas, compressed air, water, natural gas, etc. 5. Low temperature carbon steel (1CB) is suitable for low temperature valves with working temperature between -46℃ and 345℃. 6. Alloy steel WC6 and WC9 are suitable for high-temperature and high-pressure valves with non-corrosive medium working temperature between -29℃ and 595℃, and C 1 2 is suitable for high-temperature and high-pressure valves with corrosive medium working temperature between -29℃ and 650℃. 7. Austenitic stainless steel is suitable for valves that corrode any medium at the working temperature of-196 ~ 600℃. 8. Monel alloy is mainly suitable for valves containing hydrofluoric acid medium. 9. Hastelloy is mainly used for valves with strong corrosive media such as dilute sulfuric acid. 10. Titanium alloy is mainly used for valves with strong corrosive media. 1 1. cast copper alloy is mainly suitable for valves used in oxygen pipelines and seawater pipelines with working temperature of -27 ~ 200℃. 12. Plastics and ceramics are nonmetallic materials. The biggest feature of nonmetallic valves is their strong corrosion resistance, which even has advantages that metal valves do not have. -Generally applicable to corrosive media with nominal pressure N ≤ 1.6 MPa and working temperature below 60℃. Non-toxic plastic valves are also suitable for water supply industry. 2 Common materials of valve internals See Table 2-6 for common materials and service temperature range of valve internals. Please refer to JB/T 5300- 1 995. Lower temperature limit of internal components of valve/℃. F) Use the upper temperature limit/(. F) Lower service temperature limit of valve internal materials /℃ (f) Upper service temperature limit/℃ (. Type 304 stainless steel 3 16 stainless steel bronze Inconel alloy k Monel alloy Hastelloy b Hastelloy c titanium alloy nickel-based alloy No.20 alloy 4 16 stainless steel 40rc-268 (-450)-268 (-450)-273 (-460)-240 (-) 98(-3200) electroless nickel plating, chromium plating, nitrile rubber, fluororubber, PTFE nylon, polyvinyl chloroprene rubber-29 (-20)-40 (-40)-273 (-460)-268 (-450)-273 (-460)-40 (. -40(-40)427(800)427(800)86544 Table 2-7 Common materials of valve sealing surface and applicable medium The service temperature C of sealing surface material is suitable for dielectric copper -273 ~ 232, water, seawater, air, oxygen and saturated steam. 316l-268 ~ 31614 HRC steam, water, oil, gas, liquefied gas, slightly corrosive and non-corrosive medium 17-4ph-40 ~ 400 40 ~ 45hrc slightly corrosive medium Cr. ~ 400 37 ~ 42 HRC has slight corrosion, but C (normal temperature) 38HRC(650C) corrodes the medium Monel alloy KS-240 ~ 48227 ~ 35hrc30 ~ 38hrc. There are no air-free alkali, salt, food and acidic solvents such as Hastelloy BC 37153814h.