The F91 butt-welded gate valve is manufactured from martensitic heat-resistant material, featuring a self-cleaning sealing structure with an operating temperature capability of up to 540°C. Its design complies with domestic and international standards such as GB/T12234 and ASME B16.34, and it is available in various drive types including manual, electric, and gear-driven configurations.
Working Principle
The butt-welded gate valve operates by rotating the handwheel or actuating device, which drives the valve stem to move the gate vertically:
Open Position: The gate rises to the top of the valve chamber, allowing free fluid passage.
Closed Position: The gate lowers onto the seat, completely blocking fluid flow.
The sealing surface is perpendicular to the fluid direction, ensuring tight sealing through the close contact between the gate and seat.
Core Structure
Valve Body: The main section connecting pipelines, designed to withstand fluid pressure.
Gate: The key component, available in two types:
Wedge-type (Single/Double Wedge): Achieves self-sealing via a wedge angle, suitable for high-temperature and high-pressure applications.
Parallel-type: Simpler in design with easier wear repair, though slightly less sealing effective.
Seat: Forms the sealing surface with the gate, requiring material compatibility with the fluid.
Valve Stem: Connects the handwheel to the gate, transmitting operational force.
Sealing Assembly: Includes packing gland (to prevent stem leakage) and bonnet sealing.
Key Features
Advantages:
Low Fluid Resistance: Full open position ensures unobstructed flow with minimal pressure loss.
Excellent sealing: Tight gate-to-seat contact ideal for high-sealing-demand applications.
High-Temperature/High-Pressure Resistance: Wedge-type valves withstand extreme conditions.
Bi-directional Flow: No directional restrictions for flexible installation.
Disadvantages:
Longer Operation Time: Vertical gate movement results in slower opening/closing.
Complex Structure: More components than globe valves, increasing maintenance difficulty.
Sealing Surface Wear: Frequent operation may lead to leakage over time.
Applications
Oil & Gas: Long-distance pipelines, refineries, natural gas processing plants.
Chemical Industry: Corrosive media transport pipelines.
Power Generation: Boiler feedwater, steam pipelines.
Water Treatment: Municipal water plants, wastewater facilities.
Shipbuilding & Metallurgy: Marine piping systems, blast furnace cooling water pipelines.
Specification
Gate Valve, API600
Steel Valves, ASME B16.34
Face to face ASME B16.10
Butt Welding ends ASME B16.25
Inspection and test API 598
Material: F91
Size Range: 2″~36″
Pressure Rating: ASME CL, 150, 300, 600, 900, 1500, 2500
Temperature Range: -29℃~595℃
