Stock® has developed a Knife Gate Burner Line valve in accordance with the National Fire Protection Association (NFPA) standard 85. The standard requires burner line isolation at the pulverizer and at the burners to provide safety during the operation and maintenance of pulverized fuel firing systems. Stock® Knife Gate Valves (KGV) are specially constructed valves designed for extreme service. This ability to isolate portions of the burner line allows routine maintenance to be performed safely.
These valves are also used for the isolation of material feed downspouts located between the pulverizer and feeder, allowing safe access and maintenance of the feeders without exposure to dangerous hot gas. Stock® Knife Gate Valves are designed for adverse conditions. They are made to handle high velocity mixture of air and pulverized coal.
Stock® KGVs meet the individual requirements necessary to provide containment of explosion pressures as required by the NFPA standard. Stock® KGVs feature a low profile that adapts to new installations or retrofits. Internal bore surfaces include a tungsten carbide surface treatment for long life. When retracted, no portion of the gate remains in the pipe, so the flowing material does not wear the gate edge. Because of the tight seal provided by the gate seating cams, there is minimal leakage of gas.
Low Profile Design: Maintains a minumum flange-to-flange dimension to minimize space requirements. Adapts easily to new installations and retrofits.
Fully Retractable Gate: Stainless steel gate is resistant to corrosion and is smooth to prevent damage to packing seal.
Gate Plow: Cleans material from the gate guide during gate closure to prevent binding.
Tungsten Carbide Coated Wear Surfaces: Protects the internal surfaces in the material flow area from abrasion to provide extended service life.
Gate Seating Cam(s): Forces gate against a machined metal seat to minimize leakage.
Adjustable, High Temperature Packing: Provides seal around gate with external adjustments of the packing. The packing is suitable for temperatures up to 500°F.
- Special metals, packing and paint can be used for operating temperatures up to 1,000°F.
- Custom operators such as pneumatic or hydraulic cylinders or electric rotary actuators can be substituted for the standard screw.
- Special bolting patterns and valve sizes designed to fit custom and lined pipes.
- Complete pneumatic control packages with limit switches and solenoid valves.