Structure of pneumatic valve material what is required?

Pneumatic valve including body hole on the left and right end cover, respectively connected to two four-way solenoid valve load port; Upper and lower cover fixed in the valve body two end face; I-shaped cylinder valve core, the groove of the both ends of the large cylinder is equipped with sealing ring, i-shaped small cylindrical valve core in the middle of upper and lower cylinder plane parallel, and has a tilted hole, i-shaped column in a valve body, valve core hole on the two end cover can be connected with small cylindrical faces; Two end cover the steps of the axial has uniform cylinder hole is equipped with a certain amount of preloading of the spring, one end of the spring compression set on the two rings at the end of the end cover, and through the open slotted end face, in a rigid seal ring groove, the rigid seal compression on the valve core of the two plane. It will valves and pneumatic drive cylinder composite as a body, slewing drive parallel to the valve core to drive, has the advantages of simple structure, small volume, high reliability advantages. Can be applied to all kinds of fluid control system. Material and body material, should be given priority to with graphite cast iron, and indicate the brand and the physical and chemical testing data of cast iron practice. , stem material, and strive to stainless steel stem ( CR) , large diameter valves also should be embedded package of stainless steel stem. , nut material, the use of aluminum, brass or aluminum bronze and hardness and strength were greater than the valve stem. , stem bushing material, its hardness and strength shall be no greater than the valve stem, and soaking in the water condition and the valve stem, valve body don't form the electrochemical corrosion. Pneumatic valve, sealing surface material: (1) have different categories, different sealing methods and material requirements; (2) normal wedge gate valve, the material of copper ring, fixed way and grinding way shall specify; (3) soft-sealing gate valve, valve plate rubber lining material physical chemistry and health testing data; (4) valve should be marked on the valve body sealing materials and sealing surface material on board; Their physical and chemical testing data, especially the health requirements of rubber, ageing resistance, wear resistance; Usually use NBR and epdm and so on, are strictly forbidden to mixed with reclaimed rubber. , valve shaft packing: (1) as the pneumatic valve in the pipe network, is usually open/close not frequent, packing in a few years no activity, the packing is not aging, long sealing effect; (2) valve shaft packing should also be under the frequent opening and closing, good seal effect; (3) in view of the above requirements, the valve shaft packing to lifetime don't change or more than ten years will not be changed; (4) packing if need to change, design should be considered to have hydraulic pneumatic valve replacement under the condition of measures.