A problem that has troubled me for a long time: pneumatic ON/OFF butterfly valves
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Dear seniors, in the pneumatic ON/OFF specification sheet, there is a parameter regarding the valve operation mode: Open while powered (EO) and Closed while powered (EC). What does this parameter mean? Does it refer to the valve opening when the solenoid is powered, or the valve closing when the solenoid is powered? So when should one choose EC and when should one choose EO? What are the main factors to consider? (It is not a gas supply failure FO/FC), (It is not a gas supply failure FO/FC), (It is not a gas supply failure FO/FC), (It is not a gas supply failure FO/FC)
This parameter refers to the operating mode of the pneumatic ON/OFF butterfly valve, that is, whether the valve opens or closes when the solenoid is energized. Open with power (EO) means the valve opens when the solenoid is powered, while Closed with power (EC) means the valve closes when the solenoid is powered. The choice depends on the specific application requirements, with key factors including the position of the valve in the system, the properties of the fluid medium, and the flow rate. For example, in applications where rapid shutdown of the fluid is required, valves with electrically operated shut-off functions may be chosen, while in applications where rapid opening and closing of the fluid is needed, valves with electrically operated opening functions may be selected. .
Power loss, EC/EO air supply failure, FO/FC – this specification sheet is quite standard.
Under normal circumstances, the solenoid valve is energized and the air supply is connected to the cylinder; in other words, it is energized and there is air present……
Generally, a fail-safe type is chosen. When the normal solenoid is powered, it opens; when de-energized, it closes
Open when powered, closed normally； Closed with power on, normally open~ What does this mean?
For example, the emergency shut-off valve of a storage tank is designed to close in case of a fault – it shuts off when power is lost and opens when power is restored. On the other hand, the fire sprinkler valve opens in emergency situations; it opens when power is lost and shuts off when power is restored
This post was last edited by lyczli on 2023-5-26 10:10. The final state of the valve depends on: 1. Whether the valve body is normally open or normally closed； 2. When the solenoid valve operates, is the air flow on or off? ； These two are in a relational manner to each other; different combinations determine the way in which the valve operates.
The table is incomplete. It is guessed to be a start control valve with solenoids. If that is the case, then there are: the state of the control valve in the event of a gas supply failure, and the state of the control valve when the solenoid valve is powered / when it is not powered.
The last edit to this post was made by hfrs on 2023-5-27 at 13:08. Leaving everything else aside, with a fire protection standard of 607 and a hard seal, this design is incorrect. Anyone can do instrument design.