Analysis of Single Seat Control Valve and Straight Single Seat Control Valve

Straight through the single-seat control valve body, seat, spool, guide sleeve, valve cover, stem and packing and other components. Spool and stem are connected together. The connection method can be used with the interference fit pin or threaded connection pins can also be fixed valve stem and valve power station car out. A guide sleeve is arranged between the bonnet and the valve body to guide the valve spool to move up and down. Pilot hole on the sleeve, communicating with the body cavity and the valve outlet. The media in the upper part of the guide sleeve can easily flow into the valve outlet through the small holes without affecting the movement of the spool. There is only one valve plug and one valve seat in the valve body of the single seat adjusting valve. Features small amount of leakage, easy to ensure seal. Structural regulation and cut off type. The difference is that they have different shapes. The shape of the regulating spool is of the plunger type. The shape of the shut-off spool is of a plate-like or tapered shape. Another characteristic of this type of spool is the large force acting on the spool by the medium, that is, the unbalance force is large, , The case of large-caliber more serious, so only for low pressure occasions. Otherwise it should be appropriate to choose the thrust of the implementing agencies, or with the valve positioner. Straight through the single-seat control valve spool has two types of suits and anti-installed. When the spool moves down, the flow area between the spool and the valve seat is reduced, called the formal wear; otherwise it is called reverse. Valve nominal size DN and seat diameter dN marked the size of the valve. For nominal size DN <2.5mm single pilot spool, can only be installed can not be installed. Therefore, open-style must use the reactionary actuator. Air-opening control valve with the signal pressure increases and the flow area also increases; while the gas-off is the opposite, with the signal pressure increases and the flow area decreases. Single-seat control valve is adjusted by the valve body with a different electric actuators consisting of industrial field implementation of the instrument, which accepts the regulator output 4-20mA or pulse signal to the closed-loop control, to achieve the flow, pressure, temperature, liquid Bit and other parameters of the automatic control, and can choose intelligent electric actuators, and DCS, PLC and other digital transmission, to form a more intelligent control system. Electric control valve power supply voltage 220V and 380V are two kinds of electric control valve flow characteristics have equal percentage, linear, fast and other three. Compared with the pneumatic control valve, the electric control valve is widely used in electric power (energy consumption only when working), environmental protection (non-carbon emission), quick and easy installation (without complicated pneumatic pipeline and air pump work station) , Chemical industry, metallurgy, environmental protection, water treatment, light industry, building materials and other industrial automation systems. Single-seat control valve is divided into single-seat diaphragm control valve and single-seat piston control valve. It uses compressed air as power source, diaphragm or piston cylinder as actuator, and by means of electric valve positioner, converter, electromagnetic VALVES, Paul-valve and other accessories to drive the valve to achieve the switch or proportional adjustment, industrial automation and control systems to receive the control signal to complete the regulation of the pipeline media flow, pressure, temperature and other process parameters. Pneumatic control valve is characterized by simple control, rapid response, and intrinsically safe, without the need to take another explosion-proof measures. The cost of pneumatic control valve is also relative to the electric control valve to be lower, in the chemical, petrochemical and other fields, pneumatic control valve has an electric control valve incomparable advantages. Single-seat control valve structure is divided into: single-seat, sleeve, two-seater, cage and other four structures. The main types of single-seat control valve is divided into: tee, angle, high temperature type, low temperature type, bellows type, and several other types.