Gate Valve - Expanding | Neway

Neway Expanding Gate Valve

The Neway Expanding Gate Valve is a through-conduit isolation valve designed for high-pressure pipelines, primarily used in oil & gas, pipeline transmission, terminals, refineries, and liquid or gas lines where positive mechanical shut-off is required. It is an on/off valve and should not be used for throttling.

Operational Scope

• Sizes: NPS 2"–12" / DN50–DN300
• Pressure rating: ASME Class 300–2500 / PN40–PN420
• Body materials: carbon steel, stainless steel, alloy steel, duplex stainless steel
• End connections: RF, BW, RTJ
• Actuation: manual, pneumatic, electric, or hydraulic actuator

Expanding Gate Functionality

The expanding gate mechanism employs a mechanical expansion of the gate assembly towards the seats. The sealing is bi-directional and relies on a torque-based mechanical seal, not just fluid pressure. During opening/closing, the gate moves freely between sealing surfaces, reducing continuous friction and seat wear.

Comparison with Slab Gate

The expanding gate is selected when mechanical loading of the seats in the closed position and bi-directional sealing at low or high differential pressure is required. The slab gate relies mainly on floating seats and line pressure. For pigging applications, full bore, DBB requirement, or high ΔP, check bore, seat design, body cavity relief, and actuator torque.

Selection Criteria

The final specification should verify pressure class, temperature, NACE/sour service, RF/RTJ/BW connection, trim material, seat sealing, emergency sealant injection, stem sealing, and fail-safe actuator requirement.

FAQ

Is it suitable for flow regulation?
No. A partially open position can wear the gate and seats.

When is BW selected?
In critical pipeline or high-pressure lines where welded connection is required.

Which standard is referenced?
Neway complies with API 6D for expanding gate valves.