Issue with the flare valve at the compressor inlet
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Recently, an accident occurred in our catalysis workshop; during a routine adjustment, the flare valve at the compressor inlet failed to open in time, resulting in an emergency shutdown. I would like to ask some friends. Is it because the valves don’t operate properly in winter (we conduct a valve opening and closing test once a month to prevent such problems)?
It’s possible. During each night shift in winter, we tested the torches, and when we found that the wind-driven motor wasn’t working, we took action promptly; once it froze, we used steam to clear it for a long time
It shouldn’t, is the temperature very low where you are? We just check it while driving
Reply 1# mayuchun: This issue deserves attention!
Reply to 1# mayuchun: There are two control valves at the inlet of our pressure compressor for the flare system; the smaller valve has a DN200 size, features a pneumatic diaphragm actuator, and is an eccentric rotating butterfly valve； Large valve DN600, cylinder piston actuator, butterfly valve, equipped with a solenoid valve and a compressed air buffer tank; both valves are air-operated and open in the absence of air. Additionally, the large valve is equipped with a quick-open button on the DCS; a signal causes the solenoid valve of the DN600 valve to lose power, resulting in rapid opening of the valve. Faults are generally not common, but after this action the large valve does not close properly, so it is necessary to close it manually before switching back to DCS control.
We have also encountered this situation; it’s harder to open in winter, so be careful!
It’s not unusual for the freezing of water in the winter wind belt in the north to cause control valves to malfunction. It’s best to equip shut-off valves with pressure buffer tanks; such tanks can also remove water during winter, preventing valve failures. We do this for all our key valves, and it works well. For those without buffer tanks, it’s necessary to prepare steam lines for cleaning – this is a common issue in winter. It’s better to be prepared in production; don’t pay attention to those in the management or business departments – those guys in offices whose cost of a cup of tea is higher than the cost of using steam for a month, yet they keep complaining about others not being frugal. Most companies are like this