Regarding the valve position after a power outage of the electric valve.
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This post was last edited by Niuniu on 2021-9-8 07:32. Experts: During the project design process, I encountered the following issues related to electric valves; please help provide solutions. Thank you! 1) In the event of a sudden power outage, the valve position of the electric valve can only remain as it was; it is not possible to set it to open or closed in the event of a power loss. 2) Can an electric valve be equipped with two power supplies, one being a regular power supply and the other a UPS?
Use such a large UPS? It’s better to use a pneumatic valve
Using a UPS is certainly possible; in fact, in industrial applications where special conditions are required, pneumatic or hydraulic valves are generally used, while electric valves are typically employed in less critical situations
In industry, when special conditions are required, pneumatic or hydraulic valves are generally used, while electric valves are typically employed in less critical applications – this is a more scientific approach.
In the chemical industry, for fire and explosion prevention, electric devices are generally not used
The MOV operates on 220V/380V, which is the power supply voltage. Lose it, and stay where you are. There is power supply, but the control signal is lost; full open or full closed can be defined. If the safety of this valve is of particular importance, pneumatic type should be preferred, as it has deflation positions for FO and FC. If electric drives have to be used, a UPS (or electrical EPS) or a diesel generator can be used as a backup. As for how to switch circuits, the electrical engineering team is very skilled at it.
The general actuator for electric valves is a motor; once the power is cut off, the motor loses its driving force and stops moving. The power supply can be configured with dual-power redundancy (interference-free redundancy is preferred).
1) In the event of a sudden power outage, the valve position of the electric valve can only remain at its original state; it is not possible to set it to open or closed in the event of a power loss. An electric valve has no power source, so it can only maintain its valve position. 2) Can an electric valve be equipped with two power supplies, one being a regular power supply and the other a UPS? Generally, electric valves accept only one power supply and do not come equipped with a UPS, as those that use electric valves are usually gate valves with long stroke lengths, for which fast switching times are not required; in other words, there is no high urgency. Moreover, electric actuators are fitted with handwheels, allowing manual operation in the event of a power failure.
Electric valves can be equipped with two power supplies: there are two inputs (which can be two AC power sources or one AC source and one DC supply), and one output; the voltage can be either 220VAC or 24VDC. Brands such as Weidmüller and Phoenix offer such products, but they are not cheap, and no similar products have been found in China.
Regarding your two questions, it seems they are both based on security concerns. It is best to use pneumatic valves, which reset using a spring in the event of a power loss, and no second power supply is required.
There are electric valves with batteries, and they can be used to open, close, or adjust valves of any diameter. It can be turned off or on.