Pneumatic disc assembly maintenance is simple, sealing structure is reasonable, the seal replacement convenient and practical. feeding pneumatic valve pneumatic valve is mainly composed of., pneumatic valve, pneumatic valve, the sealing ring,. Pneumatic valve stem,.,. Pneumatic valve gland,, hand wheel, flange,, nut, positioning screw and other parts, the handwheel clockwise rotation, pneumatic valve closed, pneumatic valve rod moving upwards, the pneumatic valve is on exhibition type, the handwheel clockwise rotation, pneumatic valve closed, pneumatic valve stem turn down, the pneumatic valve for the next exhibition pneumatic valve standard specification: design and manufacturing standards: the structural length standard: GB/T - connecting flange standard: GB/T pressure temperature rating: GB/T - test inspection standards: GB/T -