How to realize the safe and reliable automatic protection of electric valve when power is off?

1: The valve can be protected from being damaged by the torque (overload protection or overtorque protection), and the electric actuator of the valve can be de-energized so that it does not operate.

2: Install a thermal relay on the AC contactor of the control part to protect the motor, if the motor current is too large, it will automatically power off and make its valve not operate.

But the control part will not be powered off, the electric actuator of the valve will not act to protect the valve, I don't know what type of valve you are talking about, if the integral and intelligent valve can not be installed with a thermal relay, only in the control box.

For electric valves in operation, all kinds of valves should be complete and intact. The bolts on the flange and bracket are indispensable, and the threads should be intact and not allowed to loosen. The fastening nut on the handwheel should be tightened in time if it is found to be loose to avoid wearing the connection or losing the handwheel and nameplate.

If the handwheel is lost, it is not allowed to replace it with a live wrench, and it should be completed in time. The packing gland is not allowed to be skewed or without preload clearance. For electric valves in environments that are susceptible to rain, snow, dust, wind and sand and other dirt, the valve stem should be equipped with a protective cover.

The ruler on the motorized valve should be kept intact, accurate, and clear. The seals, caps, and pneumatic accessories of the electric valve should be complete and intact. The insulation jacket should be free of dents and cracks.

It is not allowed to knock, stand on the electric valve in operation, stand on the person or support the load; In particular, non-metallic electric valves and cast iron electric valves should be prohibited.

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

Electric valves are generally equipped with manual operating devices, and when there is no electricity, people will twist and pull.

Electric valves are not sufficient. If there is no electricity in the motorized valve, the valve position will stop in its original state, will not continue to close, and will not continue to open.

Pneumatic diaphragm single-seat control valve, can be realized. In the event of loss of air supply or power signal, it can be automatically closed regardless of the position of the valve.

The solenoid valve has a two-wire one that can automatically close when the power is off. There is a three-wire one, which must be powered when it is closed.

The electric ball valve and the electric butterfly valve use a forward and reverse electric actuator, and the switch needs to be rotated by the motor. If the power is off, the motor cannot turn. So it can't be realized.

At present, there are built-in supercapacitors, which are discharged through capacitors after power failure, or external batteries, but the stability of built-in batteries needs to be improved. Especially in some harsh environments. The other is through an external battery, if a line failure is encountered, the reliability of the scheme also has some drawbacks.

Therefore, there is still a real meaning in the current domestic production of pure electric actuators, which are like pneumatics, using mechanical principles to automatically reset or turn off the power to open or close. There are imports, but the ** is very high, Shanghai Shutong automatic control technology **** intelligent electro-hydraulic actuator using the hydraulic principle, the accumulator perfectly overcome the shortcoming, can achieve the reset of the valve position (open or closed) in the power-off state. In terms of external control, it is the same as electric actuators.

It is more characteristic than electric in terms of mechanical function. If it is a small caliber, it is convenient to provide compressed air. Consider using a pneumatic single-acting actuator!

Hope mine can be helpful to you.

Austrian Schiebel has a spring-return electric actuator, which realizes that in the event of a power failure, the mechanical energy storage can be used to realize the operation of the valve, especially for some safety occasions. Products based on this principle are more reliable and have a wider range of applications than those with a backup power supply. The maximum torque of the angular stroke can be tens of thousands of nm, which is more practical.

Shenzhen Wanxun Automatic Control is the general generation of Austrian Schiebel in China.

There are a lot of homes! South Korea HKC has, power-off emergency type, it has a charging power supply inside, reset in the case of power failure, the working time is very long after the power is off, as long as the battery is charged! With RBP.

Electric actuator, I have ah, supercapacitor backup, can output 20s negative voltage after power off.

Looking for Shandong Kepais automation equipment, Noah brand, supercapacitors and spring return can be satisfied.

Do you want to import it or make it domestic, I know that Yamano has done it, but I don't know much about the specifics.

None of the electric heads are brought, but you can transform it and add a UPS.

When the fault is automatic, it seems that it cannot be realized, it has lost power in the electric how to complete, can only switch to manual shutdown.

The electric valve has a torque protection line, and the normally open point of the torque is connected to the control loop of the control box.

I don't know what you mean by the electric valve failure, according to my own understanding of the meaning to answer, that is, how to close the electric valve when there is a fault, generally there is a manual device on the actuator of the electric valve, when the hand operation is carried out, the wrench is pulled to the manual position, and the manual device is used to operate, but it is very laborious and too slow.

When the over-torque of the AWT and Tianjin Omar actuators of Rotork is driven by the motor shaft and the spindle, when the spindle encounters a large resistance (exceeding the set torque value), the spindle stops rotating, and the motor shaft will move back and forth to trigger the torque switch, cut off the power supply of the motor, and stop running. The IQ type of Rotock Intelligent has a torque sensor in front of the motor, equipped with a varistor, which also senses the force of the motor shaft to control the on/off of the motor power supply; The IQT actuator detects the force on the spindle by detecting the motor current (the current will increase when the resistance is large), and cuts off the motor power supply when it reaches a certain value.

It is normal to turn on the power, the power failure can refer to the power supply and electrical signal, the power supply is broken, the shutdown function is the backup power supply, it is not difficult to achieve, many actuators can choose this module with backup power supply, he is charging under normal power-on conditions, if the power is off in an emergency, this module can make the actuator act several times, you know that the electric actuator with load power is still relatively large, so the torque is large, and the hundreds of torques are OK. . . If the signal is off, it can generally be used with a 4-20mA control board to achieve this function.

Electric actuators, generally not like this, the American shafer gas-liquid linkage actuator may be set through the control box to meet the requirements of automatic shutdown under certain conditions, generally through the lineguard system setting, the British Rotork actuator may also have similar functions, but also through the communicator settings, specifically ask **business, you can check on the Internet**. Solenoid valves for small pipes are fine.

Probably there is no such electric actuator, you can use pneumatic actuators, which can achieve such an effect, and the valve can be automatically closed after the power is off.

Solenoid valves can, electric valves cannot.

The small diameter meets the pressure energy of the pipeline, and the large one may not be closed, but it can be manually shut off when the power is off.

As if the solenoid valve suits your requirements.

There is a clutch device inside, which realizes manual electric switching through the switching of the handle.

Manual and electric conversion actuators, which can be interchanged.

Manual: Button control relay pick-up self-locking, relay contact control electric valve to let early electric action, button control relay power loss reset, tan pants finch electric valve also power off reset.

Automatic: Time relay (double pure hole time relay) delay control electric valve energizing action and delay control electric valve power-off reset, continuous cycle.