According to the production of material can be divided into: WCB (carbon steel), LCB (low temperature carbon steel), LC3 (3.5% nickel steel), WC5 (1.25% 0.5% chrome molybdenum steel), WC9 chromium (2.25%), C5 (% 5% chromium molybdenum), C12 (9% 1% chromium molybdenum), CA6NM (4 (12% chromium steel), CA15 (4) (12% chromium), CF8M stainless steel (316), CF8C stainless steel (347), CF8 stainless steel (304), CF3 (304 l stainless steel), CF3M (316 l stainless steel), CN7M (alloy), (monel), N7M M35-1 (B) hastert nickel alloy, CW6M nickel alloy C (haas tower), CY40 nickel alloy, because