LNG Terminal Explosion In 9 Jun 2022, Freeport LNG, operator of one of the largest US export plants producing liquefied natural gas (LNG), shut for at least three weeks after an explosion. 🔹 What Went Wrong? After an inspection of a Pressure Safety Valve (PSV) it remained blocked-in: separating an LNG pipeline from the PSV. During pressure build-up, the LNG pipeline started to leak creating a methane cloud that exploded. 🔶 Recommendations 1-) A valve between a PSV and the equipment that needs pressure protection requires special attention. 2-) An isolation checklist helps to assure all valves are managed well, and end-up in the right position after maintenance. 3-) PSV maintenance requires individual permit to work. 4-) Pre Start-up Safety Review, after maintenance work, can validate the position of critical valves. 5-) Critical valves that must be open during production, can be locked with a car-seal or with a key-lock system that shows a green or red key in the control room. Experienced and knowledgeable employees are a treasure for hazardous process jobs. Source: https://lnkd.in/du7DCPJW Source: https://lnkd.in/dMqT9_pU #oil #gas #LNG #LPG #processsafety #safety #PSV #maintenance #overpressure #refinery #fire #firesafety #liquid #naturalgas #learning #desing #storage #handling #tanks #pipeline #methane #propane #explosion #safetyfirst #safetyatwork
" After an inspection of a Pressure Safety Valve (PSV) it remained blocked-in: separating an LNG pipeline from the PSV" The isolation valve should not remain blocked in. This is part of administrative control and must be followed. API 520 allows isolation valve to be used but subject to " Since improper use of an isolation valve may render a PRD inoperative, the design, installation, and administrative controls placed on these isolation block valves should be carefully evaluated to ensure that plant safety is not compromised" API 520 must be followed by operating companies as credit has been already taken for PSVs for Overpressure scenarios.
I would like share some best practices to avoid such incident. 1-Whenever any safety feature e:g PSV,ESD,SDV,F & G detectors etc. required to bypass then SORA(safety override Approval) must be intiated along with contingency plan. 2-LOTO(Lock out Tag out) of valves shall be marked on P& ID and prepare list of such valves. 3-LOTO Valve list shall be signed off before removal of any safety feature. 4-LOTO shall be signed off after reinstatement of safety features to make sure all valves are in required position. 5-If Safety override was done on DCS ,then override list shall be prepared and all safety features shall be implemented again after completion of job.
It would be interesting to hear if there are any theories about what actually caused the ignition given that any psv is presumably placed in process areas where ignition protection equipment is used although cooled lng is initially denser than air so a large release would have a very large hazard radius. Hope no one was injured.
Brian Pieri
8mo
Safety is always the top priority in hazardous process operations. Stay vigilant and ensure proper maintenance procedures are in place. 🔒 #safetyfirst
Sanjay Sheth
8mo
As per Shell DEP valve between Vessel and PSV is only for maintenance purposes and it should be kept lock open, either have to install two PSV on with special "Y" shapes unit.
Frank M.
8mo
All PSV, PVRV’s, flame arresters and blanketing valves should be inspected once the month at least and maintained every three month. There is not rule but common sense.
Mani Trivedi
8mo
Thanks for sharing
Kamel CHEBEL
8mo
Défaut process
Vice President Europe @ Vysus Group
8moDo we know what actually caused the overpressure? PSV failures do not create overpressures !