The excellent properties owned by full forging duplex stainless steel globe valve are determined by materials performances and valve structural features. Duplex stainless steel refers to ferrite and austenite inside solid solution account for half of proportion. So, duplex stainless steel combines high intensity and stress corrosion resistance to chloride of ferrite and good toughness and welding performances of austenite.
1. The valve adopts full forging or forge welding structure, having passed through nondestructive examination. The valve has been dealt with through solid solution, having fine material organization. Because of finished surface, full forging duplex stainless steel globe valve has beautiful shape.
2. The sealing pair is spray welded by using cemented carbide. Nickel welding powder, stellite and tungsten carbide also can(can also) be used. Hardness can reach HRC65. The valve has excellent wearing resistance which highly improves service life.
3. For duplex stainless steel, valve has strong corrosion resistance to hydrogen sulfide and chloridion.
4. Water, coal slurry and other media deposit and scale under high temperature, highly increasing torque which has higher requirements for stem intensity. So, 1740H precipitation-hardening stainless steel is used for stem of globe valve. The material has higher intensity after having been precipitation hardened, meeting the requirements of usage.
5. Full forging duplex stainless steel globe valve uses trunnion ball. The force on sealing pair impacted by media is lower than that on floating ball, reducing torque. The seat is designed as enclosed structure, effectively preventing spring from losing efficacy caused by deposition and scaling. The sealing pair is made from flexible graphite or plastic alloy. The material has good sealing performance and high temperature resistance. The stem is made from precipitation hardening stainless steel.
Next: Properties of Materials Used for Superhigh Pressure Valve
Previous: Tips for Choosing Valves