Compared with other valve drive devices, electric drive devices have the characteristics of wide power sources, quick and convenient operation, and easily meet various control requirements. Therefore, in the valve drive device, electric devices dominate.
According to the input mode, the valve electric device is divided into two types: multi-turn (Z-type) and partial-turn (Q-type). The former is used for lifting rod valves, including: gate valves, globe valves, throttle valves, diaphragm valves, etc.; They are used for rotary rod valves, including ball valves, plug valves, butterfly valves, etc., which are usually opened and closed within 90 degrees.
According to the protection type, the valve electric device is divided into two categories: ordinary type and special protection type.
The use environment of ordinary electric devices is as follows:
- Environment temperature: -25~40℃
- Relative ambient temperature ≤90% (at 25℃)
- Altitude ≤1000m
- The working environment requires no corrosive, flammable, and explosive media
If the working environment of the valve exceeds the capacity of the ordinary electric device, special protective products are required. Such products have various types according to the working environment.
Main technical features of special protective electric device
|Outdoor type||1. Ambient temperature: -40~40℃
2. Maximum rainfall: 50mm/10min
3. Maximum solar radiation intensity: 1.4J/cm2·min
4. There is sand, snow, frost and dew
|High temperature type||The highest ambient temperature can reach 80℃|
|Low temperature type||The lowest ambient temperature can reach -55℃|
|Anti-corrosion type||There are one or more environments containing a certain concentration of chemical corrosive media|
|High speed type||Stem speed up to 70r/min|
|Explosion-proof type||It should be able to work in an environment with explosive media|
|Ship type||Suitable for use in environments where sea water or salt fog exists on ships|
|The fire-resistant type||Should be able to open or close normally within a certain time (such as 15min) in an environment where a fire occurs (such as a temperature of 1300℃)|
|Two-speed type||Two-speed change range up to 60:1|
|Submersible type||Water resistant type Ⅰ is suitable for short-term immersion working environment (10mm, 72h); water resistant type Ⅱ is suitable for long-term immersion working environment, the water depth can be greater than 10m|
|Radiation-proof type||suitable for occasions with special requirements for nuclear power plants|
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