The technical characteristics of the pipe pneumatic ball valve

the actual working condition of the long distance pipeline conditions, its installation from the Arctic Circle to the equator, and from the mountains to the ocean floor, from the plateau to the desert, meanwhile through the earthquake zone, swamp, permafrost, rivers, lakes and hills, some erection, some buried underground, in the field operation, maintenance difficulties, require years of life. General transport medium for long distance pipeline of oil and natural gas, are treated but medium containing sulfur, impurities and foreign bodies, and require the zero-order seal. Therefore, the pipeline pneumatic valve ball strict technical requirements are put forward. ( Strength and toughness of pneumatic valves in addition to the internal medium under pressure, is due to environment temperature change under axial tension and stress. Consider landslide, land subsidence, caused by the flood of external load, material should be considered in frigid zone and the freezing region is low temperature impact toughness, prevent brittle fracture at low temperature. For all welded pneumatic valve, pneumatic valve body welding seam and heat affected zone, need according to the theory of fracture mechanics, considering its fracture toughness.
　　( Zero order pneumatic valve requires zero level, in order to ensure effective truncation of downstream end of the line. Considering the metal particles in the medium to the zero order seal, the influence of metal to metal seal as the primary sealing, PTFE/rubber to metal as a secondary seal, and once the seal failure when emergency seal measures should be taken. ( Fire safety and anti-static pipeline ball pneumatic valve design fire safety should be considered. Once the fire, pneumatic valve leakage and the leakage cannot exceed leak of the API standard. Sphere is nonmetal material clamping, may produce electrostatic, must work with pneumatic valve conduction, under the VDC, resistance & lt; Ω。
　　( DBB function ( 双布鲁克& Bleed when pneumatic valve cavity drainage, the upstream end pneumatic seat and downstream end pneumatic valve seat shall be cut off at the same time, to ensure the safety of the emissions.
　 ( To prevent the cavity pressure of the pneumatic valve clamping regardless of the pneumatic valve is in open or closed position, shall prevent medium was holding in the pneumatic valve cavity. If the medium may be holding. Is for gas medium or liquid medium to ensure the automatic discharge pressure pneumatic valve cavity, pneumatic valve cavity pressure relief does not exceed the maximum of pneumatic valve pressure rating of The Times, external pressure relief for the calibre of the pneumatic valve DN or larger. ( Pneumatic valve cavity medium can drain, and through the drain hole of pneumatic valve seal test online.
　　( Position indicator whether manual or power driving, should have obvious pneumatic valve position indicator, suggests that pneumatic valve is in open position and closed position.
　　( Torque transmission chain transmission chain of design should be at least pneumatic ball valve torque of The Times.
　 ( Vulcanization conditions on components and bolt material should has the ability of resistance to stress cracking, and meet the requirements of NACE MR.
　 ( Emergency cut off the long distance pipeline system USES satellite monitoring and control system, when the pipeline pressure drop rate or the duration of the reaches a certain value, the pneumatic valve should be urgent to break.
　 ( All-welded pneumatic valve body structure is used in anticorrosion pipeline cathode grounding and outside surface anti-corrosion, prevent the potential of groundwater corrosion and stress corrosion.