When you work in the oil and gas business, particularly if you’re around live plant or involved in construction, safety is dinned into you with all the subtlety of Trump running commentary on the Mueller investigation. It’s so effective that when you wander outside the oil and gas environment you wonder why people are deliberately trying to lose an eye or commit suicide. The industry takes safety seriously because 1) hydrocarbons are phenomenally dangerous and 2) unlike other industries, they have plenty of money.

One of the things people involved in maintenance understand is the importance of purging vessels. If you need to do some work on a tank, separator, or drum that normally holds hydrocarbons you first empty it, then you purge it with nitrogen. Then when you open it you use an ultra-sensitive gas detector to make sure there’s nothing poisonous, flammable, or explosive left inside. I don’t know where the following video is from other than it’s Chinese and I’m not entirely sure what happened, but my guess is whatever he was doing ignited residual gas in the vessel.

Be like Stalin: purge.

(Via Obo)


9 thoughts on “Purgery

  1. I used to work for Shell. A long time ago a large tanker called the Rapana went for its 5 year certification refit. A purge fail exactly as you describe led to an explosion so massive they never found some of the bodies.

  2. Staff walk down into tanks, even open top tanks, full of CO2, fall down, and then someone follows to help.
    Not even toxic (except to planet Earth), flameable, or explosive.
    Even after purging with nitrogen care would have to be taken that some oxygen was allowed back in and given time to mix.

  3. Liquid nitrogen is entirely inert, but one of the biggest lab killers.

    When it becomes gaseous nitrogen.

  4. To be honest, that actually looks fake. The guy’s clothing on the right doesn’t move, as an apparently supersonic blast of gases from the pressure vessel emerge, he doesn’t even jump in shock, he just instantaneously moves away vaguely quickly.

    The guy standing directly in the path of the jet doesn’t get his left arm torn off, which would probably happen given how fast he moves. It is not exposed the gases and yet it just magically zips off with him, and why, given the visibly flamey nature of the explosion, isn’t there any fire or smoke emerging from the access port afterwards?

  5. Another nasty one I heard about – someone at BOC inspecting a cryogenic tank. It’s very very cold (having recently been filled with liquid oxygen) but he’s wrapped up warm and takes his time to do a proper inspection, looking for the cracks or corrosion that could cause a lethal leak.

    Finished, he climbs out, and is careful to wait until the hatch is closed and sealed before he lights a refreshing cigarette (this being early 1970s).

    Of course, his thick warm clothing is saturated with pure oxygen, and he goes up like a torch, and comrades trying to suffocate the flames with a fire blanket find they’re quite indifferent since his wooly jumper and padded coat have trapped enough oxygen to burn very nastily indeed for a while.

    One of those “…so don’t do that!” asides about “how industrial machinery can kill you really quickly”, from those halcyon days in the early 1990s when engineering lecturers at Portsmouth Polytechnic had come there to sort-of-retire after interesting careers elsewhere. (A colleague of mine – more a junior mentor, really – did the same in the noughties so the tradition’s not dead)

  6. Since that’s a Pharma plant, I wonder if they were mixing powders in the vessels and this was a dust explosion triggered by a static spark. Ive worked in China, and though lovely people, they can be a bit lackadaisical when it comes to safety.

  7. @ Robert the Biker,

    Safety “culture” is hard to inculcate into societies that operate along fatalistic lines–“It’s gonna happen, no matter what I do, so why bother doing anything at all…?”.

    My favorite story about this is from Korea, a nation notably lacking in anything even slightly akin to a “safety culture” before about the mid-2000’s: Friend of mine was a construction inspector for the Army in Korea. When he arrived in-country, his predecessor for that area had been gone for well over a year, due to a death or other issue in his immediate family. As short-handed as the Army is for experienced enlisted people in low-density jobs, there wasn’t anyone available to backfill that position until my friend showed up on schedule for his assignment. The job, basically, hadn’t been done for a considerable amount of time. And, in the absence of US Army on-site supervision, the Korean contractors had been, quite literally, getting away with murder. One site, an aircraft hanger renovation, was notorious for having on-site accidents, and the like. My friend shows up, and the first inspection he does, he comes away with the Los Angeles phone book in terms of volume for things that needed to be corrected–Usual stuff, like plugs cut off cords on power tools, and bare wires plugged into sockets, things like that. Korean power tools at the time were not normally in US-friendly formats, so for the contractors to literally plug into the infrastructure…? It wasn’t easy; US-style cord ends were not generally available. So, there was all that… Lots and lots of stuff, but the general contractor was willing, so he got time to make corrections.

    One of the issues was, however, that there was no asbestos safety provision in what he was doing, and since the place was awash in the stuff, well… Problem. So, my friend told the contractor “Look, you have to come up with an asbestos-safety and abatement plan… It’s here in the contract provisions, see…?”. Contractor agreed he was supposed to do something, and that he would.

    Came the re-inspection, my friend goes through everything, finds the corrections made–Somehow, the contractor has found all the proper cord-ends for the power tools, which wasn’t easy to do in Korea at the time, and a host of other fixes had been made. Came time for the asbestos issue, my friend talks to the contractor, and the conversation goes about like this:

    “Asbestos? Asbestos… Oh, have verr’, verr’ good plan…”


    “Okay… What is it?”

    Pause, while contractor gathers thoughts.

    “Asbestos. Asbestosis take five-ten year to show up… Five-ten year.”

    Not getting a connection, my friend nods along: “OK, five-ten years for asbestosis…”.

    Contractor: “Average age Korean worker die, 55 year old…”.

    Not seeing the connection, my friend goes “OK… 55 year lifespan for Korean workers… Sad, but I understand… What about the asbestos, though?”.

    Korean contractor, triumphally: “All of my asbestos worker over 50! They dead before asbestosis…!”.

    There were reasons that a lot of Korean contractors working on US government contracts went bankrupt…

    Also, to note–Things have changed a lot over there, since the early ’90s when this story happened. Generally, for the better…

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