How to isolate, activate a safety valve, and what are the precautions?
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Isolation: 1) After the field operator receives an instruction to isolate the internal safety valve, before proceeding with the isolation at the site, they should repeat the instruction to the internal operator for confirmation. 2) First, remove the lead seals from the valve upstream and downstream of the safety valve, inform the operator inside, then start closing the upstream manual valve, followed by closing the downstream manual valve. Inform the operator that the safety valve has been isolated, and it is now possible to contact the valve team to remove the safety valve. Commissioning: 1) Inform the operator that this safety valve is about to be commissioned; first open the valve downstream of the safety valve to check for any leaks at the flanges. 2) Slowly open the valve upstream of the safety valve again to locate the leak, and inform the operator that the safety valve is now in use. Seal the valves upstream and downstream of the safety valve with lead seals. Precautions: 1) The upstream manual valve must be closed first when cutting off, followed by the downstream manual valve; the reverse order is applied when putting it back into use. 2) The bypass valve of the safety valve must not be opened under normal operating conditions. 3) The upstream and downstream valves must be fully opened to ensure the safe operation of the equipment.
I have a question: when it’s apparent that the equipment is about to reach overpressure, can’t manual relief be carried out through a bypass line? Is it necessary to wait until the safety valve activates? Doesn’t the calibration of safety valves require human effort and resources? The safety valve bypass can also be sealed with lead for record-keeping, and it is not in a state of loss of control.
Of course, pressure can be relieved through a secondary route, but in most cases the control room doesn’t have enough time to carry out operations on-site; therefore, pressure must be relieved by the safety valve itself opening, which is also one of the purposes of installing safety valves
It would be great if that’s possible; if there’s time, it’s better to release the pressure on-site.
Newbie question: Do I need to empty it before cutting?
You’re a perfect example of someone who’s incompetent and ends up causing harm to the entire team – why can’t those various pressure control valves be operated? Can’t the control valve bypass move? Do we really have to rush around in order to access the safety valve bypass line? Why isn’t there someone assigned to each valve? ?
If various control valves can regulate pressure, are they also used for pressure relief on site? Since it is necessary to relieve pressure on-site, this indicates that the pressure of the equipment is out of control and the device is in an accident state; therefore, it is important to reduce the pressure to a safe level as quickly as possible to prevent overpressure accidents.
That’s good; also, it’s essential to keep proper records of the ledger entries as well as the seal numbers, so that there is evidence available for reference.