Super Duplex Floating Ball Valve

Produced-water, seawater and chloride-bearing chemical lines often need fast isolation in a compact valve body. A floating ball design gives pressure-assisted sealing, while Super Duplex materials provide the strength and corrosion resistance required for severe service. African Valve is a leading Super Duplex Floating Ball Valve Manufacturer in Africa, supplying South Africa, Nigeria, Egypt, Angola, other African markets and international projects.

Floating Ball Sealing

The ball is supported by two seats rather than fixed between trunnions. When the valve closes, line pressure moves the ball slightly toward the downstream seat. This pressure-assisted movement increases seat contact and creates shutoff.
The design is compact and suits typical small to medium valve sizes. As diameter and differential pressure increase, operating torque and downstream seat load also rise. Larger or higher-pressure duties may therefore require a trunnion-mounted valve, especially where actuator torque or downstream seat load becomes excessive.

Super Duplex Body and Trim

Cast bodies may use ASTM A995 Grade 5A, while forged bodies and internal parts may use ASTM A182 F53 or F55. The ball, stem, gland components and seat retainers should use compatible material. Specifying a Super Duplex body with lower-alloy internals can leave hidden corrosion points inside the valve.
The alloy offers high strength and strong resistance to chloride pitting, crevice corrosion and stress-corrosion cracking. Warm seawater, stagnant cavities and welding quality still need review.

Seats, Stem and Cavity Protection

PTFE and RPTFE seats suit many clean water, hydrocarbon and chemical services. PEEK is considered where higher pressure or temperature requires greater load resistance. Metal seats are used for abrasive solids, high temperature or frequent cycling.
Depending on the design, the stem may be inserted from inside the body to reduce the risk of pressure-driven ejection. Anti-static continuity, fire-tested construction, cavity-pressure relief and ISO 5211 actuator mounting may be supplied when specified.

Technical Specifications

Size Range: DN15 to DN200
Pressure Ratings: ASME Class 150 to Class 900
Design Standards: API 608, ISO 17292 and ASME B16.34
Testing Standard: API 598
End Connections: Flanged, threaded, socket weld or butt weld
Operation: Lever, gearbox, pneumatic actuator or electric actuator
Body Materials: ASTM A995 Grade 5A, ASTM A182 F53 or ASTM A182 F55
Ball Design: Floating
Bore Type: Full bore or reduced bore
Seat Options: PTFE, RPTFE, PEEK or metal seat

Torque and Pressure Behaviour

Quarter-turn operation gives rapid isolation, and a full-bore port keeps flow restriction comparatively low when open. The actuator should be selected from maximum differential pressure, seat friction, temperature and expected deposits rather than valve size alone.
Fluid trapped in the body cavity can expand when heated after isolation. A documented cavity-relief path should be specified where thermal expansion is possible.

Industrial Applications

Super Duplex floating ball valves are used in produced-water treatment, desalination systems, seawater utilities, chemical dosing, offshore process skids, pulp and paper plants and selected oil and gas lines. Sour service may require NACE MR0175/ISO 15156 review.

Manufacturing and Inspection

Material certificates, PMI and ferrite measurement verify the body and trim. Heat-treatment records and NDT may be included where specified. Dimensional inspection confirms bore, end connections and stem interface. Hydrostatic shell and seat testing verify pressure integrity and shutoff, while operating torque can be checked for automated valves.

Ball Valve Supply Across Africa

African Valve supplies Super Duplex floating ball valves for marine, offshore, water and process installations across Africa. The enquiry should state fluid chemistry, chloride level, pressure, temperature, bore, seat material, end connection, actuator and inspection scope.