Duplex Steel Butterfly Valves

Duplex steel butterfly valve is a valve with duplex stainless steel (such as 2205, 2507, F51/F53/F55, etc.) as the core material. It is connected to the pipeline by flange, clamp or welding, and the butterfly plate is rotated (0~90°) to realize the opening and closing or regulation of the medium. Its core design includes:

Triple eccentric metal hard seal: The butterfly plate and the valve seat sealing surface adopt metal surfacing technology (such as tungsten carbide, Stellite alloy) to reduce friction and wear, and resist high temperature and high pressure.
‌Bidirectional sealing structure: Some models support both forward and reverse flow to maintain sealing performance, suitable for complex working conditions.
‌Drive mode: Supports manual, pneumatic, electric or hydraulic control, the valve body is made of duplex steel (such as 2205, 2507), which has the corrosion resistance and strength of austenitic and ferritic stainless steel.

Core Features
‌ Strong corrosion resistance:
Duplex steel contains a high proportion of chromium, nickel and molybdenum elements, and is resistant to chloride, acid, alkali and hydrogen sulfide corrosion, and is suitable for desulfurized gypsum slurry, seawater and other media.
The surface can be hardened (such as spraying tungsten carbide) to improve wear resistance.
‌ High temperature and high pressure resistance:
The operating temperature range is wide (-196℃~650℃), and the pressure resistance can reach Class 2500 (42.0MPa) or 50.0MPa.
‌ Excellent sealing performance:
The leakage level of metal hard seals reaches Class VI, and soft seals (such as rubber lining and fluorine lining) are suitable for particle-containing media.
The spring preloaded valve seat design automatically compensates for thermal expansion and contraction, extending the sealing life.
‌ Lightweight and easy to maintain:
Compact structure, full-diameter design reduces flow resistance, and supports online replacement of valve seats.

 

Duplex Steel Butterfly Valves

 

Selection Tips

‌Working parameters‌:
‌Pressure‌: Conventional models are PN16~PN40 (1.6~4.0MPa), and high-pressure models are Class 2500‌.
‌Temperature‌: Metal seals are applicable to ≤650℃, and rubber/fluorine linings are applicable to ≤200℃‌.
‌Media adaptation‌:
Containing solid particles or viscous fluids: full-bore hard seals or fluorine-lined butterfly valves are preferred‌.
Severely corrosive media: Choose 2507 duplex steel or Hastelloy valve body‌.
‌Standard compliance‌:
Must comply with API 609, ISO 5211 and other standards, and flange interfaces match ANSI, DIN or GB specifications‌.

Maintenance recommendations

‌Seal inspection‌: Metal seals are inspected for wear every 2 years, and rubber/fluorine lining seals are replaced every 1~2 years‌.
‌Lubrication management‌: Valve stems and transmission parts are filled with high-temperature grease (such as molybdenum disulfide) every 6 months‌. Operation specification: Avoid over-torque operation. Hard-sealed butterfly valves need to be cleaned of impurities on the sealing surface regularly.

Hot Tags: duplex steel butterfly valves, China duplex steel butterfly valves manufacturers, suppliers, factory, Resilient Seat Gate Valve, Integral Double Block and Bleed Valve, top entry valve, steel check valve, Butterfly Control Valve, top entry ball valve design