ZCM solenoid valve is suitable for city gas, liquefied petroleum gas, natural gas and other gases for the heating of the combustion medium pipeline to do two on-off switching, temperature control of the implementing agencies. It is widely used in the textile industry, the printing industry, gas heat setting and glass, light bulbs furnace heating and other industries gas heating automatic control system. The working principle of normally closed type valve DNl5-50 is a direct-acting low-pressure solenoid valve open the valve, DN65-300 is the second open pilot solenoid valve. Direct-acting solenoid valve to accept the electrical signal, the electromagnetic force directly lift the valve plug, the media circulation; power, the electromagnetic force disappears, the valve plug in the gravity and spring force for the next drop, the media flow. Pilot solenoid valve to accept the electrical signal, the armature in the electromagnetic force under the action of the first deputy to promote the valve plug to catch the main valve diaphragm flow through the deputy valve, reducing the pressure on the main valve diaphragm, when the Lord When the pressure on the diaphragm is reduced to a certain value, the armature will drive the main valve diaphragm and make use of the pressure difference to open the main valve and the medium will flow. After the coil is de-energized, the electromagnetic force will disappear and the armature will be reset due to its own weight, , The main valve to close. Normally open valve application of a unique direct-acting structure, when the coil to the solenoid energized, located in the coil around the static iron core assembly will produce magnetic, magnetic force to overcome the stem assembly gravity and spring back to the moving core together The valve stem assembly is sucked up, so that the valve disc and the valve seat fixedly connected to the valve stem assembly are closely and tightly sealed and the valve is closed; after the power is cut off, the valve disc restores the original force by the weight of the return spring and the valve stem assembly Bit, the valve is open, the pipeline returned to normal ventilation.