What are the protection methods after the overload of the valve electric actuator?

What are the protection methods after the overload of the valve electric actuator?

Degreasing method for valves
First, cleaning steps
Valve parts must go through the following process before assembly:
1, according to the processing requirements, some parts need to do polishing treatment, the surface can not have processing burr, etc.;
2. All parts are degreased;
3, pickling passivation after degreasing, cleaning agent does not contain phosphorus,;
4, after pickling passivation, rinse with pure water, no drug residue, carbon steel parts omit this step;
5, one by one parts with non-woven cloth dry, can not retain wire wool parts surface, or with clean nitrogen dry;
6. Wipe the parts one by one with non-woven cloth or precision filter paper stained with pure alcohol until there is no dirty color.
Two, assembly requirements
Cleaned parts must be sealed for installation. Requirements for the installation process are as follows:
1. The installation workshop must be clean, or set up temporary clean areas, such as newly purchased colorful cloth or plastic film, to prevent dust from entering during the installation process.
2, assembly workers must wear clean cotton work clothes, wear a pure cotton cap, hair can not leak, feet wear clean shoes, hands wear plastic gloves, degreasing,.
3. Assembly tools must be degreased and cleaned before assembly to ensure cleanliness
Other requirements
1. Purge the assembled valve with nitrogen for at least 1 minute.
2, the airtight test must be pure nitrogen.
3. After passing the airtight test, pack it and seal it with a clean polyethylene cap. Before using the polyethylene cap, soak it with organic solvent and wipe it clean.
4. Then seal it with a vacuum bag.
5. After packing.
6. Measures should be taken to ensure that the package is not damaged during transportation.
Iv. Acceptance requirements
The acceptance shall follow HG 20202-2000 “Code for Construction and Acceptance of Degreasing Engineering”. Before assembly, each part shall be wiped with clean precision filter paper.
What are the protection methods after overload of valve electric actuator?
Valve, as an important supporting machinery products, involves all aspects of people’s life, with the increasing demand of valve market, valve manufacturing industry in the huge demand environment, also presents a very good development prospects. Therefore, the opportunity in front of the valve market has virtually formed a product quality safety and product brand competition, each valve enterprise is in the pursuit of the product will be high-tech, high parameters, strong corrosion resistance, high life direction.
The valve electric actuator is an indispensable equipment to realize the valve program control, automatic control and remote control. Its movement process can be controlled by stroke, torque or axial thrust. In the production process, the motor is not load use, this situation is not allowed to occur. If there is such a phenomenon, it is necessary to find out the cause, generally lead to the following reasons for load:
1, the power supply is low, can not get the required torque, so that the motor stops rotating;
2, incorrectly set the torque limit mechanism, so that it is greater than the stopped torque, resulting in continuous excessive torque, so that the motor stops rotating;
3, intermittent use, heat savings, more than the allowable temperature rise of the motor;
4. For some reason, the torque limiting mechanism circuit fails and the torque is too large;
5, the use of ambient temperature is too high, relative to reduce the motor heat capacity.
Basic protection methods for overload:
1, the motor continuous operation or point operation of overload protection, using thermostat;
2, the motor blocking protection, using thermal relay;
3, for short circuit accident, use fuse or overcurrent relay.
Valve electric actuator is an indispensable equipment to realize valve program control, automatic control and remote control. Its motion process can be controlled by stroke, torque or axial thrust. Correct selection of valve electric device is very important to prevent overload phenomenon (working torque higher than control torque). The improper parameter setting of the control system will cause the oscillation of the control system. If the proportional gain of the single loop regulator is too large, the integral time is too short, and the differential time and differential gain are too large, it may cause the system to oscillate, and lead to the actuator oscillation. For the multi-loop control system, in addition to the above reasons, there is also a problem of interaction between loops, resonance problem caused by improper parameter setting. In view of the existing problems, the parameters can be re-adjusted to make the control loop have a certain stability margin without affecting the production and in line with the process control requirements.