Self-control valve with pilot

The direct effect of self-operated control valve is similar to the setting signal set by the pilot setting spring. Figure 2-18 self-control with pilot valve schematic. Icon connection for valve pressure control. If the valve after the pressure is increased, which means that the the membrane head l below the pressure is higher than the above pressure, the spool 3 is shifted to control the flow area of ​​the valve is reduced, so that the pressure drop in the valve. The same time, the role of the pilot diaphragm pressure also increased its role - is greater than the force of the setting spring 5, 6 mobile command component, baffle 7. Near the nozzle 8, the pilot output pressure decreases, in film head l above the pressure decreases, the spool 3 Move until after the valve pressure setting spring force balance date. The needle (2) is used to adjust the amplification factor of the filter medium 9 is used to filter the particulate impurities, to prevent clogging of the nozzle.
Another kind of weight as a set of self-pressure control valve. The hammer by levers connected to the stem, after its gravity enlarged stem, the valve before or after the valve pressure by the thin film converter same thrust acting on the stem, the stem does not move when only two balance . Since its structure is more simple, less maintenance, and in some unimportant or primary pressure control system is adopted, for example, the steam partial pressure cylinder pressure control.two position three way valve
Some of the pressure relief valve (including steam traps, exhaust valve, etc.), type two control valves and pressure relief valve is a self.
The level control can be converted into a pressure or differential pressure control, and therefore the self-pressure or differential pressure control valve may also be used to achieve.pneumatic hand valve
Self-temperature control valve. Self-acting temperature control valve temperature signal from the temperature of the package, the expansion of the gaseous medium when the temperature changes, the temperature within the package, so that the pressure change, the pressure signal is used as a control signal, so that the self-acting temperature control valve operation. Figure 2-19 is a schematic diagram of self-operated temperature control valve.high temperature solenoid valve