【Q&A Question No. 087】2018.03.28
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【Q&A Question 087】March 28, 2018: Briefly describe what to do after a safety valve activates Once the safety valve activates, the operator on duty should immediately reduce the pressure. If the pressure does not drop, they should promptly contact the operator outside to open the pressure control valve or the vent line, in order to bring the pressure back to normal levels and switch to the backup safety valve. Simultaneously close the upstream and downstream shut-off valves on the relief valve, remove the valve, reset the pressure, and then reinstall it. . (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) Due to the limitations on the number of posts in the “One Question per Day” section, “One Image per Day” has been moved to the registered devices section; you can access it through the directory I posted. For management purposes, if you need to access content from a few days ago, please go to the summary post below to enter the “My Registration Season” event – (Note: This event is currently ongoing in the Chemical Engineering section) https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=18978. Summary post of daily questions for the 2018 Chemical Engineering Technology Training section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888971. Summary post of daily images for the 2018 Registered Equipment section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888970. Summary post of Q&A questions for the 2018 Hydrogen Production and Hydrogenation Technology section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888968. Summary post of daily questions for the 2018 LNG Technology Discussion section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1888973. Summary post of Q&A questions for 2017 (updates have started): https://bbs.hcbbs.com/thread-1657793-1-1.html. Summary post of daily questions for 2017 (updates have started): https://bbs.hcbbs.com/thread-1657794-1-1.html. Summary post of daily images for 2017: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1875160. List of daily questions for the 2017 LNG section: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1804162. Summary post of Q&A questions for 2016 (updates completed): https://bbs.hcbbs.com/thread-1597792-1-1.html
After the safety valve operates, pressure setting must be performed again (either online or offline). If manual shutdown is required, approval procedures must be followed and preventive measures taken before proceeding.
Re-perform pressure setting (online or offline); if manual shutdown is required, approval procedures must be followed and preventive measures taken.
After the safety valve operates, the pressure control valve bypass line or vent line should be opened immediately to reduce the pressure back to the normal control range. Then, it is necessary to check whether the safety valve can reset automatically; if it cannot, the safety valve manual valve should be closed, the valve removed for repair, recalibrated, and then reinstalled.
After the safety valve operates, pressure setting must be performed again (either online or offline). If manual shutdown is required, approval procedures must be followed and preventive measures taken before proceeding.
Determine whether it can be reset after pressure release; if not, cut it off and reverify
Once the safety valve activates, the operator on duty should immediately reduce the pressure. If the pressure does not drop, they should promptly contact the operator outside to open the pressure control valve or the vent line, in order to bring the pressure back to normal levels and switch to the backup safety valve. Simultaneously close the upstream and downstream shut-off valves on the relief valve, remove the valve, reset the pressure, and then reinstall it.
After the safety valve activates, the pressure control valve bypass line or vent line should be opened immediately to reduce the pressure back to the normal range. Then, it is necessary to check whether the safety valve can reset automatically; if it cannot, the manual valve of the safety valve should be closed, the valve taken apart for repair, recalibrated, and then reinstalled.
After the safety valve operates, the pressure control valve bypass line or vent line should be opened immediately to reduce the pressure back to the normal control range. Then, it is necessary to check whether the safety valve can reset automatically; if it cannot, the safety valve manual valve should be closed, the valve removed for repair, recalibrated, and then reinstalled.
Actions to take after the safety valve operates: 1. Check whether it returns to its original position properly after operating, that is, whether the safety valve maintains a good seal as before. 2. If there are no issues such as leaks, no special action is required. 3. If there is a leak, the safety valve must be repaired and calibrated by the designated calibration department! 4. Additionally, note that if your safety valve operates frequently, it may indicate that its set pressure is incorrect; it needs to be sent to a calibration facility for re-calibration!
Re-perform pressure setting (online or offline); if manual shutdown is required, approval procedures must be followed and preventive measures taken.