Introduction of shut-off valve

The shut-off valve is a kind of actuator in the automation system. It consists of a multi-spring pneumatic diaphragm actuator or a floating piston actuator and a regulating valve. The shut-off valve has a wide range of uses , which can be used to cut off gas, combustion air, cold air and flue gas.

The shut-off valve is a kind of actuator in the automation system. It is composed of a multi-spring pneumatic diaphragm actuator or a floating piston actuator and a regulating valve. It receives signals from the regulating instrument and controls the cut-off, connection or switching of the fluid in the process pipeline. It has the characteristics of simple structure, sensitive response and reliable action. It can be widely used in petroleum, chemical, metallurgical and other industrial production sectors. The air source of the pneumatic shut-off valve requires filtered compressed air, and the medium flowing through the valve body should be liquid and gas free of impurities and particles. According to the allowable pressure difference, medium characteristics and process pipeline requirements, single-seat, sleeve, and three-way shut-off valves can be selected.

The reliability of the shut-off valve depends to a large extent on the correct selection of its structure and materials suitable for its working conditions, as well as on the operating conditions. For example, the shut-off valve can only work in two states, fully open or fully closed. When the valve disc is in the middle position in the valve seat, a large flow rate is generated due to the large pressure drop, which forms a cavitation condition, causing erosion, damaging the sealing surface of the valve disc and the valve seat, and as a result, the sealing of the closing member is lost. Due to the effect of the seepage medium on the metal, the initial small leak will quickly become a large leak.

The material, pressure rating and connection method of all shut-off valves must conform to the specifications of the equipment to which they are connected. This applies to all shut-off valves, whether it is installed directly on the equipment or on a riser connected to the equipment.