Dome pneumatic valve common faults and its solutions

a common fault analysis, dome pneumatic valve
. Dome pneumatic valve can not correctly caused dome pneumatic valve opening and closing
not correct opening and closing the reason mainly has: instrument air pressure is insufficient, connection error, electromagnetic pneumatic valve fault, no control signal to the solenoid pneumatic valve, or have hard foreign bodies stuck between the pneumatic valve core and the pneumatic valve seat, etc.
when pneumatic valves have this trouble, we need to check whether the instrument air pressure meets the requirement, whether connection error, the function of the solenoid pneumatic valve and related signal input and output is normal, when it is necessary to open the dome pneumatic valve, check whether there is foreign body card in pneumatic valves, one by one, rule out the correct operation of pneumatic valve and restore.
。 Sealing ring of inside and outside differential pressure is no guarantee that the
seal is a kind of flexible components, located between the circle and in particular, fixed by fasteners, very easy disassembly and maintenance. Sealing ring is dome is the only moving parts, pneumatic valve is the only wear parts.
according to the working principle of the dome of the pneumatic valve, sealing ring must ensure that there is a certain pressure difference inside and outside to fully expand, so as to achieve sealing effect; On the other hand, will lead to air leakage between seal and pneumatic valve core, severely damaged the dome in other parts of the pneumatic valve. However, if the sealing ring of inside and outside differential pressure is too big, and can lead to seal excessive inflation, reduce the service life of sealing ring.
in the pneumatic conveying system, usually require for instrument air pressure. MPa, to ensure the correct operation of the instrument. For conveying gas source of pressure. MPa, through reduced pressure pneumatic valve and pressure relief to the system of the actual need of pressure, but also reduced the seal of the external pressure, thus ensuring the sealing ring of inside and outside differential pressure.
it is not hard to see, sealing ring, both inside and outside differential pressure there is no guarantee that the there are two main reasons: first, the instrument air pressure is too low; Second, the reduced pressure pneumatic valve failure, can't decompression.
。 Seal the control mode of the problems
dome pneumatic valve seal generally have two kinds of pneumatic valve and mechanical valve control mode. Dome working principle of pneumatic valve to dome after pneumatic valve closure in place, sealing ring can be inflated; After seal completely exhaust, dome pneumatic valve to open.
。 Muffler jams
because the dome of the pneumatic valve using the environment there is more dust, it is easy to quickly exhaust silencer congestion on the pneumatic valve, sealing ring in the compressed gas cannot be ruled out quickly, so as to be cut pneumatic valve core of the movement.
。 Other problems
in addition to the above reasons, in the process of practical application, there are many other reasons lead to seal failure. Such as: pneumatic valve core bonding material, reduce the gap, scraping the broken seal; Transport medium containing sharp foreign body puncture seal; Connection error, solenoid pneumatic valve failure, does not control signal to the solenoid pneumatic valve, make the seal ring can't swell.
2, dome pneumatic valve fault detection and maintenance
. Fault detection
in order to timely detect the seal failure, suggest user installation seal air pressure test device, and set the correct pressure readings, participate in the signal logic control, and trigger the seal failure in time. Once sealing ring damaged should be replaced in a timely manner, or seal inflation pressure will break through its scavenging QiongTi, contact with the QiongTi over time here will be blowing loss, at the same time, it will cause the dome of the pneumatic valve in particular, such as the destruction of the other parts. After replace the sealing ring seals shall be checked and dome pneumatic valve QiongTi clearance between the evenness of the gap, about mm. Can use feeler to do detection tools.
。 Work dome pneumatic valve of inspection before
according to dome structure and working principle of pneumatic valve, pneumatic valve must do the following inspection before use.
and check all fasteners, ensure fixed dome in the pneumatic valve body and shaft bolts have been tightened; Dome pneumatic valve in front of the factory has been complete function test and inspection, but we can not avoid in the process of transportation, unloading, or installation components may be damaged and loose.
and guarantee dome pneumatic valve open or closed, sealing ring on both sides of inside and outside pressure difference, high pressure side of the gas and material will be high speed through the pneumatic valve core and seal clearance, pneumatic valve core and sealing ring wear.
and expandable seal before pneumatic valve open or shut down should be completely contraction, pneumatic valve core cutting, otherwise it will cause damage to the sealing ring.
and the expansion of the expandable seal pressure must be higher than the medium pressure pneumatic valve, sealing ring will be incomplete expansion, the inconsistency between the seal and pneumatic valve core and material leak air, air and material will flush seal, pneumatic valve core and other parts.
and cleaning the pneumatic valve is located in the process related equipment, remove the slag in the each link in the construction process, such as foreign body.