进口电动调节阀原理特点及品牌（图）

进口电动调节阀是工业自动化过程控制中的重要执行单元仪表。随着工业领域的自动化程度越来越高，正被越来越多的应用在各种工业生产领域中。德国托马斯(Thomas)电动调节阀与传统的气动调节阀相比具有明显的优点：节能（只在工作时才消耗电能），环保（无碳排放），安装快捷方便（无需复杂的气动管路和气泵工作站）。阀门按其所配执行机构使用的动力，按其功能和特性分为线性特性，等百分比特性及抛物线特性三种。

选用原则

1、电动调节阀选用主要控制参数为：公称直径、设计公称压力、介质允许温度范围、流量系数等。

2、对于要求流量和开启高度成正比例关系的严格场合，应选用专用调节阀。球阀和蝶阀一般粗调时可以选用。

3、阀门的密封性能是考核阀门质量优劣的主要指标之一。

阀门的密封性能主要包括两个方面，即内漏和外漏。内漏是指阀座与关闭件之间对介质达到的密封程度。外漏是指阀杆填料部位的泄露，中口垫片部位的泄露以及阀体因铸造缺陷造成的泄露。外漏是不允许发生的。

4、调节阀理想流量特性有快开、抛物线、线性、等百分比四种，需根据实际工作流量特性选择具有合适流量特性的调节阀。

5、调节阀公称直径的选取应根据所需阀门流通能力确定。

调节阀公称直径不应过大或过小。过大，增加工程成本，并且阀门处于低百分比范围内，调节精度降低，使控制性能变差。过小，增加系统阻力，甚至会出现阀门100%开启时，系统仍无法达到设定的容量要求。

6、调节阀的调节压差和关断压差

对于调节阀，其允许的调节压差和关断压差是其选型的重要指标。实际压差如高于调节阀允许的调节压差，阀门会出现不能准确调节的问题，严重的会损伤阀门执行器。

安装注意事项

1、调节阀属于现场仪表，要求环境温度应在－25～60℃范围，相对湿度≤95%。如果是安装在露天或高温场合，应采取防水、降温措施。在有震源的地方要远离振源或增加防振措施。

2、调节阀一般应垂直安装，特殊情况下可以倾斜，如倾斜角度很大或者阀本身自重太大时对阀应增加支承件保护。

3、安装调节阀的管道一般不要离地面或地板太高，在管道高度大于2m时应尽量设置平台，以利于操作手轮和便于进行维修。

4、调节阀安装前应对管路进行清洗，排除污物和焊渣。安装后，为保证不使杂质残留在阀体内，还应再次对阀门进行清洗，即通入介质时应使所有阀门开启，以免杂质卡住。在使用手轮机构后，应恢复到原来的空档位置。

5、为了使调节阀在发生故障或维修的情况下使生产过程能继续进行，调节阀应加旁通管路。

同时还应特别注意，调节阀的安装位置是否符合工艺过程的要求。

6、电动调节阀的电气部分安装应根据有关电气设备施工要求进行。在使用维修中，在易爆场所严禁通电开盖维修和对隔爆面进行撬打。同时在拆装中不要磕伤或划伤隔爆面，检修后要还原成原来的隔爆要求状态。

7、执行机构的减速器拆修后应注意加油润滑，低速电机一般不要拆洗加油。装配后还应检查阀位与阀位开度指示是否相符。

The electric control valve is an important execution unit instrument in the process of industrial automation process control. With the increasing degree of automation in the industrial sector, is being used more and more in a variety of industrial production areas. Germany Thomas (Thomas) electric control valve compared with the traditional pneumatic control valve has obvious advantages: energy (only when the work of electricity consumption), environmental protection (no carbon emissions), quick and easy installation (no need for complex pneumatic pipe And air pump workstations). The valve is divided into linearity, equal percentage characteristic and parabolic characteristic according to its function and characteristic according to the power used by its implementing agency.

Selection principle

1, electric control valve selection The main control parameters are: nominal diameter, design nominal pressure, medium allowable temperature range, flow coefficient and so on.

2, for the required flow and open height proportional relationship between the strict occasions, should use a special control valve. Ball valve and butterfly valve can be used when the general coarse adjustment.

3, the sealing performance of the valve is one of the key indicators of the quality of the valve.

Valve sealing performance mainly includes two aspects, namely, internal leakage and leakage. The internal leakage is the degree of sealing between the valve seat and the closing member to the medium. Exposure is the leakage of the valve stem, the leakage of the gasket in the mouth and the leakage of the valve body due to casting defects. Exposure is not allowed to happen.

4, the ideal flow characteristics of the control valve are open, parabolic, linear, and other percentage of four, according to the actual working flow characteristics with the appropriate choice of flow characteristics of the control valve.

5, the selection of the nominal diameter of the valve should be determined according to the required valve circulation capacity.

The nominal diameter of the regulating valve should not be too large or too small. Too large to increase the cost of the project, and the valve is in the low percentage range, the adjustment precision is reduced, the control performance is deteriorated. Too small, increase the system resistance, and even the valve will open 100%, the system still can not meet the set capacity requirements.

6, the adjustment valve regulator pressure and turn off the pressure difference

For the control valve, the allowable adjustment of differential pressure and shutdown pressure difference is an important indicator of its selection. The actual pressure difference is higher than the adjustment valve to adjust the pressure difference, the valve will not be able to accurately adjust the problem, serious damage to the valve actuator.

Installation Precautions

1, the control valve is a field instrument, requiring ambient temperature should be in the range of -25 ~ 60 ℃, relative humidity ≤ 95%. If it is installed in open air or high temperature occasions, should take waterproof, cooling measures. In a place where there is a source away from vibration sources or increase anti-vibration measures.

2, the control valve should be installed vertically, under special circumstances can be tilted, such as the tilt angle or the valve itself is too large when the weight of the valve should be increased support.

3, the installation of the valve control valve generally not from the ground or the floor is too high, the pipe height greater than 2m should try to set the platform to facilitate the operation of hand wheel and easy maintenance.

4, the control valve should be installed before the pipeline cleaning, remove dirt and welding slag. After installation, in order to ensure that no impurities remain in the valve body, the valve should also be cleaned again, that is, access to the media should make all the valve open, so as not to impurity stuck. After using the handwheel mechanism, it should be restored to the original neutral position.

5, in order to make the control valve in the event of failure or maintenance of the production process can continue, the control valve should be bypassed.

At the same time should also pay special attention to the installation of the valve position is consistent with the requirements of the process.

6, electric control valve electrical part of the installation should be based on the relevant electrical equipment construction requirements. In the use of maintenance, in the explosive place is strictly prohibited power cover maintenance and pry the surface of the explosion. At the same time in the disassembly do not knock or scratch the exposed surface, after repair to restore the original explosion-proof requirements of the state.