Cut-off valve failure

Both DO and DI are gone at the same time. Most cables have problems. Broken? Burned?

Several possibilities: 1. Logical issue: Is XV-1101 an SIS-controlled valve?； Or it is a DCS-controlled valve that does not meet the opening conditions ； 2. Hardware failures: Failures in components such as cards, wires, solenoids, etc., leading to abnormal valve operation ； Have the instrument maintenance technician review the drawings and conduct an on-site inspection; this will allow the cause of the fault to be determined quickly.

The DI feedback described by the original poster is gone as well. So the likelihood of logic, card, or instrument failures is relatively low. So I guess it’s the wiring

You’ve provided too few criteria for judgment; this isn’t a complex issue, and a technician with a certain level of skill can determine it easily. By the way, it’s best to avoid making unprofessional comments – they are of no help to those who ask questions and can even have a negative effect.

Check the on-site feedback switch; usually, when the system issues a command to open the valve, if no feedback signal indicating that the valve has been opened is received within the specified time, the system will automatically issue a command to close the valve, resulting in an error. The Zhejiang University ZKControl system has this functionality

We are from Rossi & Soni; the valve was open but suddenly closed. Switching it to manual mode didn’t work to reopen the valve, and then an alarm was triggered indicating a loss of signal, along with a timeout issue

A few minutes later, manually closing the valve showed that it had been closed properly; when the valve was then opened, there was a response, so everything returned to normal. I’m not sure what caused this

It is a valve controlled by the SIS, but there is no command in the SIS to close this valve separately. Attempting to operate the valve manually has no effect; instead, it flashes yellow, indicating a loss of feedback and a feedback deviation. The valve closed after ten minutes, and there was some action when it was opened again; I’m not sure what the reason is

It was manually turned on after ten minutes; I don’t know why

From your subsequent description, the conditions that can trigger the valve to operate are air pressure, the on/off state of the air path, and the operation of the solenoid valve. The possibility of the solenoid valve operating is very low; it may operate if the interlock conditions are met, or if there is a break in the power supply to the solenoid valve or if the voltage is low. Since, according to your description, the interlock conditions are not met, and the solenoid valve is powered by a UPS. Therefore, it is inferred that the issue lies in the air supply system; a decrease in air pressure is to blame. When the air pressure drops, the solenoid valve fails to operate, and the valve gradually moves to its faulty position, which is why no signal indicating the valve’s position is received for an extended period of time, triggering a status alarm. After the air pressure increased, the valve was pushed to full open, and the valve position feedback was also received. Therefore, it is recommended to check the air line pressure; generally, a DN15 air line can supply up to four valves, while a DN20 one can supply 10 valves. Too many are hung up; if multiple valves operate simultaneously, it will lower the air pressure. Sometimes it is caused by a drop in the air supply main pressure. The above is my personal analysis of one of the reasons for reference. On a side note, this is a SIS valve; since it has failed to the off position, isn’t there any mechanism designed for resetting it? ? It can be operated manually even after being turned off without the need for a reset? It seems that this interlock design is unreasonable and does not comply with the standards.