I earnestly implore those experts in self-control to give some guidance: since the DCS interlock shutdown is set as F.C., is it possible to design the system so that the valve closes when power is applied?
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The specification for the isolation valve XV-30501 is F.C; the interlock logic dictates that the valve should close when powered on； Does this design meet the design standards?
Under normal circumstances, a F.C. (Fail Close) valve will close automatically when the power is lost. It is feasible to design the isolation valve XV-30501 to close when powered, and this meets the F.C. standards. During design, it should be ensured that the valve remains open when power is available, and automatically closes in the event of a power loss to ensure the safety of the system. .
The interlock logic is to close the valve when power is applied； Does this design meet the design standards? This definitely doesn’t meet the standards; what if the connection is broken and there’s no power supply? How can it then provide protection?
The feed valve is generally a air-operated valve, and its safe state is the closed position; therefore, an air-operated valve should be chosen. In the absence of air or a control signal, the valve remains in the closed state.
This post was last edited by jlshnlhj on 2024-10-5 09:17. The XV-30501 (XV-30502, XV-30701) consists of a pneumatic valve FC + a solenoid valve. The air supply is controlled by a solenoid valve; it closes when powered, which constitutes a \"interlock\". The key is to determine whether several conditions (TT30501, PT30501, etc.) are for control or safety interlock; it is estimated to be for control on the DCS side. In the case of safety interlocks, there is indeed a risk that the wire-break interlock may not function.
When you bought the valve, did you make sure to specify the electrical interlock? Is the interlocking direction consistent with the fault direction? If you bought it in the same way, just use this configuration. With a design that requires lifelong accountability, such interlock logic generally doesn’t have any errors. Generally speaking, DCS interlocks are triggered by a value of 1, while SIS interlocks are triggered by a value of 0; so... for a valve controlled by a DCS interlock, it’s not a problem to have it triggered by a value of 1. This still depends on the unified design regulations. There are no standards requiring that DCS interlock valves cannot use a 1-interlock.
Add FC for the location of air supply failure in the specification sheet, and add EO (valve opens in case of power loss) for the solenoid valve. So it will turn off when powered. When there is a gas supply, the solenoid valve does not supply power to open the valve; when the solenoid valve is powered, air is released and the valve closes. Loss of air supply; Valve FC closes
FC stands for fail-safe valve, while XV refers to a on/off valve. Therefore, there are two types of failure conditions for valves: failure in the output signal command of the valve and failure in the power source signal. Theoretically, as long as one of these two failures occurs, it is possible to achieve fault shutdown. In cases where the valve output signal commands it to close, the valve selected must be in an open state when there is no output command, and capable of closing when such a command is issued. A power source failure (pneumatic/electric/hydraulic, etc.) means that in the absence of such power, the valve can be designed to remain in the open position (for example, relying on natural elements such as the spring in the actuator to keep the valve in the closed position).
Take a look to see if what you say is contradictory, or if it was copied by AI
Process requirements for valves FO FC