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-   -   oxy explosion at LPL (https://www.pprune.org/engineers-technicians/56707-oxy-explosion-lpl.html)

Rob_L 16th Jun 2002 15:49

oxy explosion at LPL
 
Two engineers were injured one seriously charging an oxygen cylinder which exploded at Liverpool. The question is should we still be charging O2 in uncontrolled enviroments in this day and age. This practice seems to have been outlawed in many countries. Any thoughts?

Bullishit 16th Jun 2002 18:30

In My outfit which is of a moderne fleet,we change O2 bottles and charge them in the shop as the a/c are not equiped to charge them in situ.
Excuse my ignorance but i thought it was illegal practice to charge bottles nowadays other than an approved method/workshop.
Sorry to hear of the injuries.

nitro rig driver 16th Jun 2002 21:29

well if your working n reg ac then charging onboard is a definate no no ...can/t say now that i am working for an eu company that i have ever seen the rules/instructions for charging oxy onboard

hope the guys are ok but you know who is going to get the blame

rightstuff 16th Jun 2002 21:44

Hope the two engineers are OK.Which bottles were being recharged,the crew or the cabin portable type?

time-ex 16th Jun 2002 22:59

My thoughts are with the injured guys. Here at Big Airways we charge O2 bottles in situ on the aircraft although there are very stringent rules about the process. In days gone by our instrument guys did it because it was thought they were less likely to introduce grease into the process - but now - almost anyone can do it and I'm sure it is only a matter of time before we have an incident. When it happens I quess one of the stringent rules will have been broken and I know who will be considered to be at fault and it won't be the company.
As an aside - what problems are encountered transporting charged cylinders? Does this present an equal risk?

Rob_L 17th Jun 2002 21:15

Last I heard it was a portable. When it went off the flash was seen from the fire station 300 metres away.

One engineer is reported as badly hurt requiring skin grafts and with eye damage.

morroccomole 21st Jun 2002 11:41

Rob_L; was this incident at your company or another?

Rob_L 25th Jun 2002 04:47

Channel Express and Emerald

Airbornespanner 2nd Jul 2002 14:55

Standard practice for us is to remove bottle place into reinforced container, which is part of the oxy recharge rig and top up bottle. Saves any mishaps. All tools required are in special tool box on the rig as well.

NightHawkZero 3rd Jul 2002 21:30

Enquiry ???
 
From an (untrained) observers point of view, can I ask how these elements interact so violently ??? any knowledge is good. :confused:

Bre901 5th Jul 2002 14:35

Risks of oxygen
 
Pure oxygen under pressure is so reactive that it will react violently with many solid materials (including cylinder wall), provided an adequate source of ignition energy is given.

That energy maybe as small as a shock, a spark from a steel wrench, or the oxidation of tiny amounts of grease (including fingerprints on exposed parts).

Oxygen filling procedures are stringent and should be followed very carefully. Care and cleanness (sp?) are essential.

FlukeFixer 5th Jul 2002 21:29

Firstly how are the guys doing that were injured?
Bre901 is correct, pure oxygen will react with most things that have a flash point. Even metals at high pressure or temperatures. The more available Oxygen the lower the flash point becomes. Once low enough, any source of ignition will start a fire, more oxygen the faster the fire will burn. That is why cotton clothing should be worn, Synthetics easily produce static sparks.
The fire storms in USA are a typical example. If you think Bread burns in Toaster, dip it in Liquid Oxygen, light it and it will burn like an Signal flare!
Most oxygen systems are made free of anything combustable. (within limits)Clynders are best made from Stainless steel or polished mild steel. Dry Oxygen is used to prevent any rust forming; FeO2 to FeO3, which becomes pourus and can flake off. If a high pressure clynder became pourus the passing Oxygen can accelerate the reaction (which also produces some heat). It also severely diminishes the structual rigidity of the clynder. Thats why they have a shelf life and should be discarded if completely depressurised. If conditions are right the bottle can explode due to the structual faliure, sparks from flying metal can start a fire/ explosion and can destroy an Aircraft. Hence NO PASSENGERS on board whilst charging.
Slow charging is used to minimise leaks, but also reduces vibration, structual stresses, prevents any icing or heat build up within the pipe work and doesn't freeze or melt open the valves.
Hope this explains the procedures we follow when charging Oxygen.

KwikPhix 13th Jul 2002 13:40

I've been charging oxygen systems using both Gaseous and Liquid oxygen for about 19 years now, to be perfectly honest this is the first time i've heard of a serious incident whilst charging. I'm not saying that there haven't been any during that time , it's just that I haven't heard of or noticed them. I am intrigued to know what caused this unfortunate accident. Several possible causes instantly spring to mind; Grease on the fittings or tools being used, Failure of a component in the system alowing gas to escape, a spark caused by static or metals rubbing/banging together, dare i say it... Over pressurisation causing a failure ? I hope the Guys make a full recovery and also we gett to know the outcome of any investigation to try to prevent it happening again.

In a similar Vein;
I often cringe when i see fuel being drained or decanted from an aircraft fuel tank or container. Two incidents that spring to mind are:

1) Fuel being drained from an RAF Pembroke at RAF Wildenrath in the 80's, I believe that there was no bonding lead being used and a spark ignited the fuel vapour severely damaging or destroying the A/C and the building.

2) at KAAB Dhahran Saudi Arabia 1999. An F-15 was being drained of the last few gallons of fuel in the brand new ( but Un-ciommisioned) Fuel Shop Hangar. The guy doing the job forgot to attach the bonding lead, he remembered part way through the operation. As he tried to attach the Bonding lead to the A/C a spark jumped and 'Flashed' the fuel vapour, as the Technician (a Saudi Military guy) jumped out of the way he fell & knocked over the draining bucket containing fuel. You can imagine what happened next..... The resultant fire completely destroyed the brand new f-15 A/C and the building !!! as well as badly injuring the technician. I know this to be true as I was actually watching the firemen battling to put out the blaze.

It is also alledged that the Brand new Purpose built Fuel shop/Hangar had a state of the art fire detetection and suppressant sytem installed, however they had been having so many bugs and false alarms it had been turned off !!!

It's often a dangerous world we all work in - be carefull and lucky now.


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