Pneumatic control valve is widely used in petroleum, chemical, electric power, metallurgy and other industrial enterprises in various industries due to its simple control, fast response, and intrinsic safety, without additional explosion-proof measures. We have to pay attention to its longevity. How can we make it live longer? Then daily inspection and maintenance are essential. Next, Weifang Tianhe Valve Manufacturer will introduce the inspection and maintenance of pneumatic control valve.

氣動(dòng)調(diào)節(jié)閥采用石墨一石棉為填料時(shí)，大約三個(gè)月應(yīng)在填料上添加一次潤(rùn)滑油，以保證氣動(dòng)調(diào)節(jié)閥靈活好用。如發(fā)現(xiàn)填料壓帽壓得很低，則應(yīng)補(bǔ)充填料，如發(fā)現(xiàn)聚四氟乙燥填料硬化，則應(yīng)及時(shí)更換；應(yīng)在巡回檢查中注意氣動(dòng)調(diào)節(jié)閥的運(yùn)行情況，檢查閥位指示器和調(diào)節(jié)器輸出是否吻合；對(duì)有定位器的氣動(dòng)調(diào)節(jié)閥要經(jīng)常檢查氣源，發(fā)現(xiàn)問(wèn)題及時(shí)處理；應(yīng)經(jīng)常保持氣動(dòng)調(diào)節(jié)閥的衛(wèi)生以及各部件完整好用。

When graphite asbestos is used as the packing for the pneumatic control valve, lubricating oil should be added to the packing once every three months to ensure the flexibility and ease of use of the pneumatic control valve. If the packing gland is found to be pressed very low, the filler shall be supplemented. If the PTFE dry filler is found to be hardened, it shall be replaced in time; Pay attention to the operation of the pneumatic control valve during the patrol inspection, and check whether the valve position indicator is consistent with the output of the regulator; For pneumatic control valves with positioners, the air source shall be checked frequently, and problems found shall be handled in a timely manner; The sanitation of pneumatic control valve and the integrity of all parts shall be kept frequently.

氣動(dòng)調(diào)節(jié)閥常見(jiàn)故障及產(chǎn)生的原因：

Common faults of pneumatic control valve and their causes:

（一）氣動(dòng)調(diào)節(jié)閥不動(dòng)作

（1） Pneumatic control valve does not act
 

故障現(xiàn)象及原因如下：

The fault phenomena and causes are as follows:

1．無(wú)信號(hào)、無(wú)氣源。①氣源未開(kāi)，②由于氣源含水在冬季結(jié)冰，導(dǎo)致風(fēng)管堵塞或過(guò)濾器、減壓閥堵塞失靈，③壓縮機(jī)故障；④氣源總管泄漏。

1. No signal or air source. ① The air source is not turned on, ② the air duct is blocked or the filter and pressure reducing valve are blocked and out of order due to the freezing of water in the air source in winter, ③ the compressor fails; ④ The main air supply pipe leaks.

2．有氣源，無(wú)信號(hào)。①調(diào)節(jié)器故障，②信號(hào)管泄漏；③定位器波紋管漏氣；④調(diào)節(jié)網(wǎng)膜片損壞。

2. There is air source but no signal. ① Regulator failure, ② signal pipe leakage; ③ Positioner bellows leaks; ④ The adjusting omentum is damaged.

3．定位器無(wú)氣源。①過(guò)濾器堵塞；②減壓閥故障I③管道泄漏或堵塞。

3. The positioner has no air supply. ① The filter is blocked; ② Pressure reducing valve failure I ③ Pipeline leakage or blockage.

4．定位器有氣源，無(wú)輸出。定位器的節(jié)流孔堵塞。

4. The positioner has air supply but no output. The orifice of the positioner is blocked.

5．有信號(hào)、無(wú)動(dòng)作。①閥芯脫落，②閥芯與社會(huì)或與閥座卡死；③閥桿彎曲或折斷；④閥座閥芯凍結(jié)或焦塊污物；⑤執(zhí)行機(jī)構(gòu)彈簧因長(zhǎng)期不用而銹死。

5. There is signal but no action. ① The valve core falls off, ② the valve core is stuck with the society or the valve seat; ③ The valve rod is bent or broken; ④ Frozen valve seat and valve core or coke block dirt; ⑤ The actuator spring is rusted due to long-term disuse.

（二）氣動(dòng)調(diào)節(jié)閥的動(dòng)作不穩(wěn)定

（2） Unstable action of pneumatic control valve

故障現(xiàn)象和原因如下：

The fault phenomena and causes are as follows:

1．氣源壓力不穩(wěn)定。①壓縮機(jī)容量太??；②減壓閥故障。

1. The air supply pressure is unstable. ① The compressor capacity is too small; ② The pressure reducing valve is faulty.

2．信號(hào)壓力不穩(wěn)定。①控制系統(tǒng)的時(shí)間常數(shù)（T＝RC）不適當(dāng)；②調(diào)節(jié)器輸出不穩(wěn)定。

2. The signal pressure is unstable. ① The time constant (T=RC) of the control system is inappropriate; ② The regulator output is unstable.

3．氣源壓力穩(wěn)定，信號(hào)壓力也穩(wěn)定，但氣動(dòng)調(diào)節(jié)閥的動(dòng)作仍不穩(wěn)定。①定位器中放大器的球閥受臟物磨損關(guān)不嚴(yán)，耗氣量特別增大時(shí)會(huì)產(chǎn)生輸出震蕩；②定位器中放大器的噴咀擋板不平行，擋板蓋不住噴咀；③輸出管、線(xiàn)漏氣；④執(zhí)行機(jī)構(gòu)剛性太??；⑤閥桿運(yùn)動(dòng)中摩擦阻力大，與相接觸部位有阻滯現(xiàn)象。

3. The air source pressure is stable, and the signal pressure is also stable, but the action of the pneumatic control valve is still unstable. ① The ball valve of the amplifier in the positioner can not be closed tightly due to the wear of dirt, and the output vibration will occur when the air consumption increases especially; ② The nozzle baffle of the amplifier in the positioner is not parallel, and the baffle cannot cover the nozzle; ③ Air leakage of output pipe and line; ④ Actuator rigidity is too small; ⑤ The friction resistance of the valve rod is large during movement, and the contact part is blocked.