Gate Valve — Bolted Bonnet (Cast Steel)
Specifications
- Manufacturing standard: API 600 / BS 1414 / ASME B16.34 / MSS SP-144
- Testing standard: API 598 / BS EN 12266 Part 1
- Pressure rating: ASME Class 150 to 4500
- Size range: ½” to 24″ (DN15 to DN600)
- End-to-end dimension: ASME B16.10
- Flange standard: ASME B16.5 / BS / AWWA / EN / DIN
- Flange face finish: Raised face, serrated finish (125–250 AARH)
- Butt-weld end: ASME B16.25
- Wedge type: Flexible wedge / split wedge (one-piece cast)
- Stem: Rising stem, trapezoidal threads, burnished finish, single-piece forged
- Bonnet: One-piece bolted design
- Yoke: Pillar yoke construction
- Seat: Seal-welded seat rings with lapped finish
The Cast Steel Gate Valve with Bolted Bonnet is a full-bore, bi-directional isolation valve designed for full open / full close service across oil and gas, power generation, chemical, and water treatment applications. The wedge-to-seat flow path provides unobstructed, low-pressure-drop flow when fully open, while the bolted bonnet construction delivers a robust, field-maintainable pressure boundary that allows internal access for inspection and seat servicing without removing the valve from the pipeline. Manufactured across a size range of ½” to 24″ and pressure classes from ASME 150 through 4500, the valve accommodates the broad range of pressures, temperatures, and process media encountered in general industrial service.
Features
- Seal-welded seat rings are permanently fused to the body, eliminating the risk of seat loosening in service and preventing inter-leakage paths between the seat ring and body bore that threaded or press-fit seats can develop over time
- Flexible wedge and split wedge configurations with balanced design absorb pipeline deflections and thermal deformation without transmitting bending stress to the seating faces, reducing the risk of seat damage and leakage under thermal cycling
- Single-piece forged stem provides superior strength and fatigue resistance compared to fabricated stems, with trapezoidal threads and burnished finish minimising operating torque and extending packing life
- One-piece bolted bonnet allows straightforward field access to internals — gland packing, stem, and wedge — without specialist tooling, supporting planned maintenance and emergency repair over the full service life of the valve
- Pillar yoke construction opens up clear access to the bonnet flange and packing gland area, making re-packing and bonnet bolt inspection practical on installed valves in congested pipework environments
- Highly finished, lapped seat faces maintain tight shut-off across extended service cycles, with the valve designed to self-compensate for minor misalignments caused by pipeline loading or thermal expansion