淺談如何給控制閥選擇電動執行器產品
How to choose the electric actuator product for control valve？

在日常工作中我們該如何來為一臺閥門選用電動執行器產品?下面就讓天蝶閥門有限公司給大家說一下吧！
In the daily work, how to choose a electric actuator product for a control valve? Let the Tandy Valve Co., Ltd. give you a look!
在流程工業中控制閥主要用來控制工藝介質的流量、溫度、壓力和在設備中的液位等參數，選擇閥門電動執行器時，除了考慮所調節的工藝介質變化對被控參數的影響外，還要考慮工藝介質特性，氣態還是液態，單相流還是多相混合流、是否有腐蝕，介質的操作狀態如溫度、壓力、流量、閥上下游兩側壓差等因素的影響。

（羅托克電動執行器）

In the process industry, the control valve is mainly used to control the parameters such as flow rate, temperature, pressure, and liquid level in the equipment in the process medium. When selecting the valve electric actuator, in addition to considering the effect of the changed controlled process medium on the controlled parameter, it is also necessary to consider the characteristics of the process medium, it is gas or liquid, single-phase or multi-phase mixed flow, whether there is corrosion, the operating conditions of the medium such as temperature, pressure, flow, pressure difference between the upstream and downstream sides of the valve and other factors.

（DKJ電動執行器）

比如黑水流量控制閥，由于黑水中含有固體顆粒，除了考慮工藝流量，溫度、壓力以及在閥門兩側壓差大小這些參數外、還需要考慮黑水中的固體顆粒對閥內件沖刷的影響，考慮控制閥節流以后會不會出現閃蒸、氣蝕現象，如果閥門前后壓差太大，介質節流后發生閃蒸或氣蝕，對閥門會產生很大的危害，這些因素都需要在閥門電動執行器設計選型中充分的考慮。
For example, the black water flow control valve, because the black water contains solid particles, in addition to considering the process flow, temperature, pressure, and the size of the pressure difference between the two sides of the valve, but also need to consider the impact of solid particles in black water on the valve interior erosion, Considering the control valve after throttling will not occur flash steam and cavitation phenomenon, if the valve before and after pressure difference is too large, the media after throttling will not occur flash steam and cavitation, the valve will have a great deal of damage, these factors need to be in full consideration for the design and selection of valve electric actuator.

（QT電動執行器）

此外在電動執行器選擇時還要考慮控制閥流量特性對所控制的工藝參數的影響，選擇閥門的流量特性是等百分比、線性、還是快開型，對一些苛刻的特殊工況、開車工況，與正常流量比較，如果流量調節的范圍很寬，就要求閥門有大的可調比特性。
In addition, when selecting the electric actuator, the influence of the flow characteristic of the control valve on the controlled process parameters must be considered. The flow characteristics of the valve are selected to be equal percentage, linear, or quick opening type, and for some severe special working conditions and driving conditions, compared with the normal flow, if the range of flow adjustment is very wide, the valve requires a large adjustable ratio characteristic.
設計人員在控制閥選型過程中，對閥門使用的過程條件充分了解后，要明確提出閥門的技術要求和參數，比如控制閥門的類型，像偏心旋轉閥、直通閥、軸流閥、平衡式的籠式控制閥等，閥體、閥內件材質;閥體尺寸大小，連接形式、壓力等級;閥門定位器、閥附件等要求，還會給出一些特定參數比如調節速度、閥門全開或全關時間、噪聲等級等。
In the control valve selection process, with the full understanding of the valve using process conditions, designers should not only clearly specify the valve technical requirements and parameters, such as the type of control valve, like eccentric rotary valve, straight valve, axial flow valve, balanced cage control valve, etc.. The valve body, valve trim material; valve body size, connection form, pressure rating; valve positioner, valve accessories and other requirements, but also give some specific parameters such as adjusting speed,  the valve fully open or fully closed time, noise level and so on.