The selection of valve electric actuator should be based on what?
The QOTO valve is a device that operates the valve and connects it to the valve. The device is electrically driven and its motion can be controlled by stroke, torque or axial thrust. The performance and use of valve electrical equipment depends on the type of valve, the operating specification of the equipment and the position of the valve in the pipe or equipment. Therefore, it is important to properly select the valve installation equipment and consider how to prevent overload. Correct selection of valve installation equipment should be based on:
1, operating torque: Operating torque is the choice of valve electrical equipment The most important parameters.
The output torque of the electrical equipment shall be 1.2-1.5 times times the maximum torque of the valve operation.
2, Work Thrust: valve electrical equipment has two major structures. First, no push plate is installed, that is, direct output torque. The other is to install a push plate to convert the output torque to the output thrust through the stem nut of the push plate.
3, Output shaft number: Valve electrical equipment output shaft transfer number and valve nominal diameter, stem pitch and number of threads related. According to M = H/zs calculation (formula: M is the sum of the number of turns of electrical equipment; H is the valve opening height mm; S is the pitch mm of the rod drive thread; Z is the stem screw.
4, Stem Diameter: for the multi-point valve stem, if the electrical equipment allowed the maximum stem diameter does not pass through the stem, then the valve can not be assembled into an electric valve. Therefore, the inner diameter of the hollow output shaft of the electrical equipment must be greater than the outer diameter of the stem.
For some rotary and multi-rotary valves, the stem diameter and critical groove size should be fully considered, regardless of the diameter of the stem, in order to make the part work properly.
5, Output speed: The valve quickly open and close, easy to produce water hammer.
Therefore, the appropriate opening and closing speed should be selected according to different conditions of use.
6, Installation and connection: installation of electrical equipment includes vertical installation, horizontal installation and floor installation; The connection mode is: push plate; stem opening (open stem multi-rotary valve); Black strip rotation multiple times; no push plate; stem blockage; Part R ear apparatus is widely used in Valve program control and automatic control. Remote control is essential equipment, mainly used to close the valve. However, the special requirements of valve electrical equipment can not be ignored. Torque or axial force must be limited. Typically, the valve actuator uses a torque limiting coupling. Control torque is also determined when electrical equipment specifications are fixed.