Shanghai Lianggong valve teaches you to solve the impact of scale on the valve. Whether it is solenoid valve or electric valve, scale is one of their hazard factors, which will not only cause valve leakage, but even affect the normal operation of the valve in serious cases. Therefore, how to eliminate the impact of scale is a common concern of technicians in valve repair factory.

控制閥的工藝涉及的范圍實在太廣,不過由于設計執(zhí)行機構(gòu)和使用填充材料不同造成控制閥性能差還是可以總結(jié)出其規(guī)律的:

The process of the control valve involves too wide a range. However, due to the poor performance of the control valve caused by the different design of the actuator and the use of filling materials, its law can be summarized:

1、工藝過程里死區(qū)的存在會使過程變量偏離原設定點。所以控制器的輸出加大到足于克服死區(qū),只有這一糾正性的動作才會發(fā)生。

1. The existence of dead zone in the process will make the process variable deviate from the original set point. Therefore, the output of the controller is increased enough to overcome the dead zone, and only this corrective action will occur.

2、①影響死區(qū)的主要因素。摩擦力、游移、閥軸扭轉(zhuǎn)、放大器的死區(qū)。各種控制閥對摩擦里敏感是不一樣的,比如旋轉(zhuǎn)閥對于由高的閥座負載引起的摩擦力就非常敏感,故使用時注意到這一點。但是對于有些密封型式,高的閥座負載是為了獲得關(guān)閉等級所必須的。哈哈,這樣,這種閥設計出來就非常差,容易引起很大的死區(qū),這對過程偏差度的影響是顯而易見的,簡直是決定性的。

2. ① main factors affecting dead zone. Friction, travel, valve shaft torsion, dead band of amplifier. The sensitivity of various control valves to friction is different. For example, the rotary valve is very sensitive to the friction caused by high seat load, so pay attention to this when using. However, for some seal types, a high seat load is necessary to obtain a closing grade. Haha, in this way, the design of this valve is very poor, which is easy to cause a large dead zone, which has an obvious and decisive impact on the process deviation.

②磨損。閥門在正常使用時出現(xiàn)磨損是在所難免的,但是潤滑層的磨損是厲害的的,根據(jù)我們實驗證實,潤滑旋轉(zhuǎn)閥只經(jīng)過幾百次循環(huán)動作,潤滑層差不多可以剛刷子使用(夸張點,不然寫文章很郁悶)。另外壓力引起的負載也會導致密封層的磨損,這些都是導致摩擦力增加主要因素。結(jié)果呢?就是給控制閥的性能于毀滅性!

② Wear and tear. Wear of the valve during normal use is inevitable, but the wear of the lubricating layer is severe. According to our experiments, the lubricating rotary valve only goes through hundreds of cycles, and the lubricating layer can almost be used with a brush (exaggeration, otherwise the article is very depressed). In addition, the load caused by pressure will also lead to the wear of the sealing layer, which are the main factors leading to the increase of friction. What happened? Is to give the performance of the control valve to destruction!

③、填料摩擦力是控制閥摩擦力的主要來源,使用的填料不同,造成的摩擦力有很大的差別。

③ Packing friction is the main source of friction of control valve. The friction caused by different packing is very different.

④、執(zhí)行機構(gòu)的類型不同也對摩擦力有根本性的影響,一般來說彈簧薄膜執(zhí)行機構(gòu)比活塞執(zhí)行機構(gòu)好。

④ Different types of actuators also have a fundamental impact on friction. Generally speaking, spring membrane actuators are better than piston actuators.