The bellows stop valve relies on the valve lever pressure to make the sealing surface of the valve clack closely fit with the sealing surface of the valve seat and prevent the medium from flowing. The bellows stop valve only allows one-way flow of medium, and has directivity during installation. The structural length of the bellows stop valve is longer than that of the gate valve, and the fluid resistance is large, so the sealing reliability is not strong during long-term operation.

When the medium enters the bellows stop valve from below the valve clack, the resistance to be overcome by the operating force is the friction between the valve stem and the packing and the thrust generated by the pressure of the medium. The force to close the valve is greater than the force to open the valve, so the diameter of the valve stem should be larger, otherwise the valve stem of the cast iron threaded stop valve will be bent.

The bellows stop valve has reasonable structure and reliable sealing. The double durable bellows sealing design (bellows+packing) ensures zero leakage of the valve stem. No fluid loss, improving plant equipment safety. And meet the sealing standard. The sealing surface is welded with Co based cemented carbide, which has good wear resistance, corrosion resistance, friction resistance and long service life. The valve rod is quenched and tempered and the surface is nitrided, with good corrosion resistance and friction resistance; The up and down position indication of the valve rod is more intuitive.