Pneumatic valve materials and classification

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. Main categories:) Pneumatic V regulator) Pneumatic type O cut-off valve) Torque type cylinder valve) Electromagnetic diaphragm valve) Pneumatic diaphragm valve straight program) Electric valve pneumatic V type valve use and features A, use is A quarter-turn structure, it has to do with the valve positioner, proportional control can be realized; V valve core is the most suitable for all kinds of regulating occasions, with large rated flow coefficient, adjustable than large, good sealing effect, zero sensitive regulation performance, small size, can be installed in vertical lie. Apply to control gas, steam, liquid medium. B, characteristics: a quarter-turn structure, by the v-shaped body, actuator, positioner, and other accessories; There is a best than the intrinsic flow feature of such as approximation; With double bearing structure, small starting torque, has excellent sensitivity and speed of induction; Strong ability of shear. C, pneumatic piston actuators using compressed air as power source, through the movement of the piston drives the crank arm to degrees of rotation, to make the automatic opening and closing of the valve. Part of it is: the adjusting bolt, actuator housing, crank arm shaft, piston, connecting rod, cylinder block, cylinder, cardan shaft. D, the working principle of pneumatic control valve, pneumatic control valve is composed of actuators and regulating mechanism. Is a thrust part of the regulating valve actuator, it according to the size of the control signal pressure to produce the corresponding thrust, promote regulating mechanism. The body is the adjustment of the pneumatic control valve components, it is directly contact with control agent, regulating the flow of the fluid. Standard English name ANSI/NFPA T. 。 R - Pneumatic valve. 美国/ T。 。 R - Supplement: hydraulic components pressure rating. Test fatigue and determine containing metal shell of the hydraulic pressure Pneumatic valve of Pneumatic valve - 压力等级补充NFPA / T。 。 R - 流体动力组件- 方法验证fatigueestablishing爆破压力评级压力包含信封的金属流体动力气动valveBS - Input signals as to b/pressure gauge in the assessment Method of pneumatic valve positioner evaluating pneumatic valve positioners with input signal of the to LBF/in