Hastelloy C276/B3 Trunnion Mounted Ball Valve Manufacturer in Africa

Large-bore and high-pressure chemical systems can produce seat loads that make a floating ball valve difficult to operate. Supporting the ball on trunnions reduces this movement and allows the seats to move toward the ball. African Valve is a leading Hastelloy C276/B3 Trunnion Mounted Ball Valve Manufacturer  in Africa, supplying South Africa, Nigeria, Egypt, Angola and major African and export projects.

Trunnion Support Mechanism

The ball is held by upper and lower trunnions. It rotates but does not move substantially downstream under line pressure. Spring-energised seats are pushed toward the ball to maintain sealing contact.This design reduces operating torque and suits larger sizes, higher pressures and automated service. Side-entry, top-entry, two-piece and three-piece constructions may be offered depending on pipeline access and maintenance requirements.

Alloy and Seat Selection

C276 is used for broad mixed chemical and chloride service. B3 is selected mainly for reducing acids and requires careful assessment of oxygen and oxidising contamination.The body, ball, stem, trunnions, seat retainers and exposed springs should use the selected alloy or a proven compatible material. Bearing and seal materials must also withstand the fluid and temperature.Soft-seat options include PTFE, RPTFE and PEEK. Metal seats suit abrasive solids, high temperatures or frequent cycling. Depending on the project, double block and bleed, cavity-pressure relief and emergency sealant injection may be included.

Technical Specifications

Size Range: DN50 to DN900

Pressure Ratings: ASME Class 150 to Class 1500

Design Standards: API 6D, API 608 and ASME B16.34

Testing Standard: API 6D or API 598

End Connections: Flanged RF, RTJ or butt weld

Operation: Gearbox, pneumatic, hydraulic or electric actuator

Body Materials: Hastelloy C276 or Hastelloy B3

Ball Design: Trunnion mounted

Body Construction: Side entry, top entry, two-piece or three-piece

Seat Options: Soft seated or metal seated

Pressure and Cavity Control

When the valve is closed, pressure may become trapped in the body cavity. A pressure-relief arrangement allows excess cavity pressure to discharge to the upstream or downstream side according to the seat design.Double-block-and-bleed capability should be confirmed from the exact valve configuration. It should not be assumed solely from the trunnion-mounted construction.

Applications

C276 trunnion valves are used in corrosive chemical transfer, offshore injection, chlorine-processing systems and pollution-control pipelines. B3 versions suit selected reducing-acid service where the process chemistry is controlled.

Manufacturing and Inspection

Large nickel-alloy valves require controlled casting or forging, machining and welding. PMI, NDT, dimensional inspection, shell testing, seat testing, cavity-relief checks and actuator functional testing may be included.