Hard seal butterfly valve

Product Overview

This Triple Eccentric Metal Seat Butterfly Valve (Standard Model: D343H Flanged, D373H Wafer) is an industrial-grade valve for harsh working conditions, with 3D triple offset friction-free structure as the design foundation and metal-to-metal seat seal pair as the core. Different from conventional soft seal butterfly valves, it adopts an integrated elastic metal seat matched with metal disc for sealing, which completely solves the industry pain points of rubber/PTFE soft seals such as poor high temperature resistance, easy aging and non-erosion resistance. It features bidirectional zero leakage, high temperature and wear resistance, high pressure and corrosion resistance, and long service life.

Fully compliant with API 609, MSS SP-68, GB/T 12238 and other international standards, it covers sizes DN50-DN1200 (NPS 2″-48″), widely used in key industrial pipelines with high temperature, high pressure and severe erosion, such as power plants, petrochemical, coal chemical, metallurgy, oil & gas storage and transportation, and municipal heating.

Key Features

1. Core Metal-to-Metal Seat Seal System, Zero Leakage & Strong Weather Resistance Under Full Working Conditions

   Fully focused on the core design of metal seat, tailor-made for harsh working conditions:

   1. Adopting integrated elastic metal seat structure, the seat body and sealing surface are integrally formed, matched with metal disc to form a metal-to-metal hard seal pair, completely avoiding the problems of soft seal material aging, high temperature deformation and medium corrosion failure, suitable for ultra-wide temperature range from -40℃ to 650℃;
      

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   2. The sealing surface of the seat and disc adopts plasma spray welding Stellite hard alloy, supersonic spraying tungsten carbide process, with surface hardness up to HRC40-65, excellent high temperature resistance, erosion resistance, anti-seizure and particle wear resistance, perfectly suitable for severe wear conditions such as high temperature steam ≤425℃, media containing solid particles, dust and slurry, with service life more than 8 times that of ordinary soft seal seats;
      

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   3. The elastic metal seat realizes self-energized bidirectional sealing, the medium pressure pushes the seat to closely fit the disc, the higher the pressure, the tighter the seal. It can automatically compensate for thermal expansion and contraction under high and low temperature working conditions, avoiding high temperature jamming and sealing failure, reaching ANSI/FCI 70-2 Class V bidirectional zero leakage.
      

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2. 3D Triple Offset Friction-Free Structure, Low Torque Operation & Long Cycle Life

   Optimized 3D triple offset design (shaft eccentricity, disc eccentricity, sealing cone eccentricity) ensures the metal seat and disc sealing surface only contact at the moment of full closing, and completely separate after opening, no sliding friction during the whole stroke. It completely avoids wear of the sealing surface caused by frequent opening and closing, with operating torque over 60% lower than ordinary concentric butterfly valves, and cycle life more than 10,000 times, ideal for frequent operation conditions.

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3. High-Strength Valve Body & Full Material Adaptation, High Pressure & Corrosion Resistance

   The valve body adopts integrated precision casting with uniform wall thickness and strong structural rigidity, pressure rating covers PN16-PN100 (Class150-Class600). Optional flanged and wafer type connection, face to face dimension complies with API 609 and GB/T 12221, perfectly compatible with GB, ANSI, JIS, DIN standard flanges. Core parts are available in WCB carbon steel, 304/316 stainless steel, duplex steel, WC6 Cr-Mo steel, etc., with excellent acid, alkali and chloride corrosion resistance for various corrosive media conditions.

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4. Full Drive Adaptation & Complete Safety Protection, Stable & Reliable

   Reserved ISO 5211 standard mounting pad for direct connection with lever handle, worm gear, pneumatic/electric actuators, suitable for local manual operation and remote automatic control. Standard anti-static device, blow-out proof stem, high temperature flexible graphite packing seal, optional API 607 fire-safe structure, which can still maintain effective sealing of the metal seat under fire conditions, ensuring the safe operation of the pipeline in all aspects.

Applications

Product Summary