Industry new

Grasp the selection of several electric control valves

As the degree of automation that accompanies the industrial sector has increased year by year, many applications have been applied to various industrial production fields. Compared with the traditional pneumatic control valve, in fact, the electric control valve still has many very obvious advantages, such as environmental protection, easy installation and other advantages. Of course, when selecting such a regulating valve, it is actually necessary to pay attention to several points.

Because the electric control valve is a very important execution unit instrument in industrial automation process control. Therefore, it is necessary to grasp or understand the main points of this selection:

In general, this electric control valve is selected, mainly as a control parameter, such as nominal diameter, design nominal pressure, medium allowable temperature range, flow coefficient, and the like. So when you are choosing, you can use these as reference parameters, perhaps to help you choose the most suitable valve for you.

I believe that some occasions will require the flow rate and opening height in direct proportion to the relationship, when the occasion requires this ratio relationship, then you can directly use the most dedicated regulator valve, in general, this ball valve or butterfly valve can be used in coarse tuning.

All valves, including pneumatic control valves, will be one of the main indicators for evaluating the quality of valves. Of course, the seal of the valve also includes two aspects, namely, the inner leakage and the outer leakage. The inner leakage is mainly the degree of sealing achieved by the medium between the valve seat and the closing member. The leakage is the leakage of the valve stem condiment, the leakage of the gasket in the mouth, and the leakage of the valve body due to casting defects. General leakage will not be allowed to happen.

Speaking of the optimal flow rate characteristics of the regulating valve, it is actually four kinds such as fast opening, parabola, linear, and equal percentage, and it is necessary to select the most suitable valve with the appropriate flow characteristics according to the most practical working flow characteristics.

The selection of the nominal diameter of the regulating valve in the electric control valve must be determined according to the required valve dredge capability. Of course, if the regulating valve nominal diameter can not be too big or too small. If it is too large, it will increase the cost of the project, and it will allow the valve to be in a low percentage range, and the accuracy of the adjustment will also be reduced, resulting in poor control performance. However, if it is too small, it will increase the resistance of the system, and even cause the valve to be 100% open, the system will still be unable to meet the set capacity requirements.

PREVIOUS：Analysis of electric butterfly valve brings uNEXT：Understand the working principle of pneumatic