Ball Valve - Conventional Power Plant | Neway

Neway Ball Valve for Conventional Power Plant Service

Neway ball valves are specified for isolation duties in conventional power plants where pressure, temperature, shutoff requirement, and cycling frequency must be checked against the project datasheet. Typical size range is DN15–DN600 / 1/2"–24", with pressure ratings ASME Class 150–4500 / PN16–PN760. Body materials include carbon steel, stainless steel, and alloy steel.

Connections and Operation

• End connections: BW for welded high-temperature lines, SW for small-bore piping, and RF flanged where removal for maintenance is required.
• Operation: lever, handwheel through gearbox, pneumatic actuator, hydraulic actuator, or electric actuator.
• Actuator sizing should consider differential pressure, break torque, seat material, cycling frequency, and fail position.

Typical Applications

• Main and auxiliary steam isolation lines
• Feedwater systems and boiler drain lines
• Condensate, blowdown, and auxiliary water services
• Instrument air and auxiliary gas headers
• Equipment isolation in turbine island and boiler island piping

Suitable Media and Operating Conditions

Applicable media include steam, boiler feedwater, condensate, treated water, compressed air, nitrogen, and compatible auxiliary gases. Selection must account for steam temperature, pressure drop, flashing risk, erosion potential, oxygen content in water service, and required leakage class.

Sealing and Seat Options

• Soft seats: used where temperature and pressure are within polymer seat limits and tight shutoff is required.
• Metal seats: preferred for high-temperature steam, abrasive condensate, frequent cycling, or services with thermal shock.
• Stem sealing and body gasket selection should match temperature, fire-safe requirements, and site fugitive-emission practice.

Standards and Documentation

Project specifications commonly reference ASME B16.34, ASME pressure classes, applicable flange or weld-end standards, and pressure testing to API 598 or equivalent project requirements. Material certificates such as EN 10204 3.1 may be required for pressure-retaining parts.

Variant Selection

• BW type: lower external leak paths; suitable for permanent high-energy piping.
• RF type: easier removal; gasket management and bolt load control are required.
• Gear-operated type: used on larger sizes or high differential pressure.
• Actuated type: used for remote isolation, interlocks, trip logic, or process control sequences.

FAQ

Can it be used for throttling? A standard ball valve is primarily an isolation valve. Throttling requires a characterized or control-trim design.

What drives the final selection? ASME class, design temperature, Δp, body material, end connection, seat type, leakage requirement, and actuator torque margin.