Problems to be aware of when purchasing imported electric actuators
1. Drive energy
The most commonly used drive energy source is a power source or a fluid source. If the power source is selected as the drive energy source, a three-phase power source is generally selected for a large-sized valve, and a single-phase power source can be selected for a small-size valve. General electric actuators are available in a variety of power types. Sometimes DC power can be selected, and the battery can be safely operated by installing a battery. There are many types of fluid sources, first of all different media such as compressed air, nitrogen, natural gas, hydraulic fluid, etc. Secondly, they can have various pressures, and the third actuator has various sizes to provide output torque.
2, valve type
When selecting an actuator for an electric actuator valve, it is necessary to know the type of valve so that the correct actuator type can be selected. Some valves require multi-turn drive, some require single-turn drive, and some require reciprocating drive, which affects the choice of actuator type. Generally, a multi-turn pneumatic actuator mechanism is more expensive than an electric multi-turn actuator, but a pneumatic actuator of a reciprocating straight stroke output is less expensive than an electric multi-turn actuator.
3, the size of the moment
For 90 degree swing valves such as: ball valves, disc valves, plug valves, it is best to obtain the corresponding valve torque through the valve manufacturer, most of the valve manufacturers are by testing the valve required operating torque at the rated pressure, they will Torque is provided to the customer. For multi-turn valves, these valves can be divided into: reciprocating (lifting) motion – stem does not rotate, reciprocating motion – stem rotation, non-reciprocating – stem rotation, valve stem must be measured The diameter, stem connection thread size has been determined by the actuator size.
4. Selection of actuators
Once the type of actuator and the required drive torque for the valve are determined, it can be selected using the data sheet or selection software provided by the actuator manufacturer. Sometimes the speed and frequency of valve operation need to be considered. The fluid-driven actuator adjusts the stroke speed, but the electric actuator of the three-phase power supply has a fixed travel time. Some small-size DC electric single-turn actuators adjust the stroke speed.