The shuttle valves are designed to close tightly the dust reservoirs which operate under the pressure different from its atmospheric value, and to empty these reservoirs without decompression. The shuttle valves are used in the ash collecting systems and the continuous coal pulverization systems.
The shuttle valve consists of two separate valves connected by a spacer. Each valve consists of a body with built-in machined basket and a shaft driven flap which fits tightly to the basket. The flap is driven by the shaft which is moved by the actuator powered feed-screw.
For ease maintenance the hatches are provided in the body of the damper.
Depending on medium temperature required, such dampers are offered in the following design versions:
- made of carbon steel 1.0038 for operating temperature up to 425 °C
- made of stainless steel 1.7715 for operating temperature from 425°С to 585°С
- made of stainless steel 1.4541 for operating temperature from 585°С to 610°С
- made of stainless steel 1.4835 for operating temperature from 610°С to 900°С
The shuttle valves can also be made of aggressive media resistant materials. These valves are 100% gas-tight. All pilofacturing holes of the dampers are sealed with the packing glands and the gaskets. The shafts are sealed by means of the packing glands’ rings. This prevents the breakthrough of gases through the packing assemblies. The above stated valve arrangement along with the use of high-quality materials guarantee the high serviceability of the shuttle valves and provide a long operating time, as well as a long time between repairs. In addition, the seal air system may be provided.