1. To prevent abnormal pressure rise in the middle chamber, a pressure relief hole is set at the inlet side of the ram.

2. Determine the top length of the bonnet according to the working temperature of the valve to ensure the reliable sealing of the valve stem packing.

3. The materials of packing, gasket and other parts shall be selected reasonably according to the working temperature.

4. Strictly control the chemical composition, low-temperature impact toughness and other mechanical properties of materials.

5. A variety of piping flange standards and sealing surface types are adopted, which are suitable for various engineering needs.