Nickel Aluminum Bronze Butterfly Valves

Falcon High-Performance Nickel Aluminium Bronze (NAB) Butterfly Valves (ASTM B148 C95800 / NES 747)

At Falcon, we engineer and manufacture industrial-grade Nickel Aluminium Bronze (NAB) Butterfly Valves designed for high-capacity flow control, bi-directional isolation, and severe throttling in marine, offshore, defense, and high-salinity industrial piping systems. Cast in premium ASTM B148 UNS C95800 / C95400 and DEF STAN 02-747 (NES 747), our butterfly valves deliver exceptional resistance to seawater erosion, marine biofouling, cavitation, and chloride stress-corrosion cracking in compact, space-saving footprints.

Key Features & Advantages

• Unmatched Marine & Seawater Corrosion Resistance: Protective nickel-rich oxide film provides complete immunity to raw seawater, brackish water, high-velocity brine, and stagnant crevice corrosion.

• Inherent Anti-Fouling Properties: High copper content naturally prevents macro-biological growth (barnacles, mussels, and algae) inside wetted disc and body channels, reducing maintenance downtime.

• Lightweight & Space-Saving Design: Quarter-turn operation with compact wafer, lug, or double-flanged body designs minimizes weight and piping envelope on offshore topsides and vessel hulls.

• Low Operating Torque & High Cycle Life: Precision-machined NAB disc and high-strength stem materials (UNS C63200 / C63000) ensure smooth, low-friction rotation under high differential pressures.

• Zero-Leakage Seating Performance: Precision-molded resilient seats (NBR, EPDM, Viton) or metal-to-metal seating deliver bubble-tight ISO 5208 Rate A / API 598 shut-off.

Butterfly Valve Constructions Offered

• Concentric Resilient-Seated NAB Butterfly Valves:

  • Design: Resilient elastomer liner (EPDM / NBR / Viton) vulcanized or bonded to the body for $100\%$ zero-leakage shut-off.

  • Best For: General seawater intake, ballast systems, and HVAC cooling towers up to Class 150.

• Double-Offset (High Performance) NAB Butterfly Valves:

  • Design: Eccentric disc shaft displacement minimizes seat friction and wear during rotation, significantly extending seat lifespan.

  • Best For: High-cycle throttling, reverse osmosis pump isolation, and medium-pressure marine service.

• Triple-Offset (Bi-Directional Zero-Leakage) NAB Butterfly Valves:

  • Design: Metal-to-metal seating arrangement with an angled conical eccentric geometry, eliminating sliding friction.

  • Best For: Firewater deluge mains, high-temperature seawater, and critical offshore platform isolation where resilient elastomers are unsuitable.

Primary Applications

• Naval Surface & Sub-Surface Defense Vessels: Submarine hull valves, ballast tanks, weapons cooling systems, and sonar dome flushing loops (NES 747 compliant).

• Offshore Oil & Gas (FPSO & Platforms): Topside seawater cooling systems, firewater deluge lines, ballast transfer, and HVAC seawater loops.

• Seawater Desalination Plants (RO & Thermal): Raw seawater intake headers, filtration feed isolation, and concentrated brine discharge loops.

• Power Generation & Coastal Facilities: Condenser cooling water lines, coastal thermal power plant cooling intakes, and marine dockyard piping.

Quality Assurance & Testing Standards

Every Falcon Nickel Aluminium Bronze Butterfly Valve undergoes comprehensive inspection before shipment:

• 100% Positive Material Identification (PMI) on body, disc, and stem components to verify exact NAB alloy chemistry.

• Hydrostatic Shell & Bi-Directional Seat Testing per API 598 and ISO 5208.

• Non-Destructive Examination: Radiographic (RT), Liquid Penetrant (PT), and Ultrasonic (UT) testing options per ASME B16.34 standards.

• EN 10204 Type 3.1 & Type 3.2 Material Test Reports (MTRs) for complete heat traceability.

Contact Falcon for Your Valve Requirements

Whether you require standard ASTM B148 C95800 wafer butterfly valves , our engineering specialists are ready to assist. Contact Falcon today with your project dimensions,pressure classes,and actuation requirements.