The pressure parts of electric ball valve are made of cast copper, cast iron, ductile iron, high silicon cast iron, cast steel, forged steel, high and low alloy steel, stainless and acid resistant steel, Hastelloy, Inconel, Monel, duplex stainless steel, titanium alloy, etc. And can produce a variety of electric, pneumatic, hydraulic valve drive device. In the face of so many valve varieties and such complex working conditions, in order to select the valve products suitable for installation in the pipeline system, I think that we should first understand the characteristics of the valve; secondly, we should master the steps and basis for selecting the valve; thirdly, we should follow the principle of valve selection. 1. There are generally two kinds of valve characteristics, service characteristics and structural characteristics.
1. Use characteristics of electric ball valve: it determines the main performance and scope of use of the valve. The types of valve (closed-circuit valve, regulating valve, safety valve, etc.); product type (gate valve, globe valve, butterfly valve, ball valve, etc.); materials of main parts (valve body, valve cover, stem, disc, sealing surface) of valve; valve drive Methods, etc. Structural characteristics: it determines some structural characteristics of valve installation, repair, maintenance and other methods. The structural characteristics include: the structural length and overall height of the valve, the connection form with the pipeline (flange connection, threaded connection, clamp connection, external thread connection, welding end connection, etc.); the form of sealing surface (insert ring, threaded ring, surfacing, spray welding, valve body) Valve rod structure (rotating rod, lifting rod), etc.
2. The steps and basis of valve selection are as follows: (1) selection step 1. Define the use of valve in equipment or device, and determine the working conditions of valve: applicable medium, working pressure, working temperature, etc. 2. Determine the nominal diameter and connection mode of the pipe connecting the valve: flange, thread and welding, and determine the operation mode of the valve: manual, electric, electromagnetic, etc.