Driver Needed. CDL +Hazmat required. Must know how to apply brakes to avoid a bus…
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I’m looking around trying to find something to back the current thinking about pure acetylene’s propensity to spontaneously explode over 30 psig. Clearly, we have some limits on use/storage/movement/and so forth, but the curious part of me really wants to know “how did we learn that?”. I mean, a scientific paper describing how exactly that was determined would be great. But I stumbled across the above.
It’s not the result of a high-pressure explosion of acetylene, but instead of one high pressure cylinder that outgassed (secondary to the collision), then combusted either against a vehicle’s hot exhaust or was ignited by a rich-burning engine.
Then all hell breaks loose.
You’d want an acetylene cylinder to outgas when it’s being boiled. Much more preferable. Outgassing with a dangerous but impressive flaming spire is significantly more agreeable (they have plugs that will melt to release the gas) than having the 250 psi steel bottle burst and release its high-pressure acetylene+acetone mix into a flames.
Rapid decomposition ensues.
Fine… explodiness ensues.
Those bottles weigh perhaps 60 kg. Empty, they’re perhaps 55 kg. If you knock the valve off of it, it’s a rocket.
Those rockets are not at all predictable in their paths. While you -do- see those impressive flame plumes behind them, it’s not the fire accelerating them. Any acceleration is entirely from the gas pressure inside the cylinder.
Scary stuff.
So what about oxygen bottles? Typically oxygen bottles are at slightly higher pressure than acetylene. About 2000 psi compared to acetylene cylinder’s 250 psig. Industrial, medical, aviation — with a few uncommon exceptions (low-pressure O2 tanks for example), oxygen bottles are typically charged to about 2000 psig.
It’s a bit scary to see what even a small medical-grade O2 cylinder can do when its valve is expeditiously detached from a 2000 psi tank… inside of an old-style ambulance. That little rocket very quickly added an extra window to truck’s metal box.
Fortunately, while oxygen isn’t flammable, it does tend to aide in combustion. Think Fire Triangle. Fire would have been horrifying.
Speaking of oxygen and fires, many years after I observed the result of what an unsecured O2 cylinder could do to an ambulance, there was a guy who once used LOX to rapidly (instantly?) create a ready to use BBQ grill by using a single match. Ah… here’s it is:
With certainty, the winds of change direct the courses of our lives. It’s not always clear from where the winds blow nor to where. They may sometimes seem stale and stagnant. Other times, powerful and terrifying. They may even not take us where we wish or need to be. Nevertheless, we will sail them and give our all to make the best of that wind when it blows.
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I posted that nine years ago and on The Book of Face. I’ve no idea why I didn’t post it here. And even less of an idea of what prompted it.
Today, it’s something that I, and everyone else, needs to hear.
Obviously, we’ll only have just begun the third quarter when we return from spring break in a week or so. But, as we received several weeks ago the tools list for the fourth and fifth quarters, it’s something to start preparing for over the term… oh, and you have the summer quarter to prepare for it as well.
Here’s the list with a few links to specific recommendations and suitable alternatives.
Required Tools for Airframe II
ARCFT 235, 236, 237, 238
All of these tools are required by the second week of Airframe II Quarter! Students starting out of sequence must have all tools from General and Airframe I lists also! As always, consult your instructor for clarification if you are unclear about a tool description.
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As we’ve done this a few times, I’m just going to provide some links to the search results for plausible vendors that we’d used before: Amazon, Harbor Freight, Home Depot, Lowe’s, and the recommended vendor if one was given.
I’m not seeking out the various tool suppliers that may have been mentioned by the instructors because many may not (or don’t) have a search mechanism, a web presence, or both. You can certainly have a look at them and consider your own value of the time you spend on it.
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Snap Ring Plier set (ATS E100-022 or equal). 1 set
You’ll need snap ring pliers to both expand snap rings and compress.
Often, you’ll get directed toward tools that are adapters for power drills or (worse) impact drivers. Don’t! Just regular old 1/4″ to 3/8″ socket adapters.
1/4″ 12 Point universal joint socket set 5/16″ through 9/16″ (Genius US-206S or equal). 1 set
These sockets are rather difficult to track down. You can find them in several places, but they’re quite expensive — $220-ish. I think it’s quite unreasonable. Genius Tools has them listed for about $40 for the specific recommended item number. But they’re back ordered. Honestly, I’d rather pick them up for $40 than nearly six times as much.
Yes, I know — I’d previously admonished the use of Tool-Truck vendors. Because I’ve been seeking for several months and am not getting any response from Genius Tools, I’m including the $295 (!) and $310 (!!) set options from Mac Tools and SnapOn above.
It seems I’ve lost about 40 hours of my time over the mast eight weeks trying to chase down a savings of $250 seems a losing pursuit. That’s time I won’t get back. ]
1/4″ Bit Holder 1/4″ Drive (Yardstore #56110 or equivalent). 1 ea.
All these tools are required by the second week Powerplant Quarter! Students starting out of sequence must have all tools from general and airframe list also! As always, consult your instructor for clarification if you are unclear about a tool description.
Slick mag E-Gap tool (Aircraft Spruce PN # T150 or equivalent) Students may make in Gen A as extra project, 1 ea.
While this tool and the timing lock tool above are rather inexpensive, there will be another $12 for ultra-basic shipping. What one might plan as a $30 purchase will actually be about $42.
Eng. Cable Sling **Note. All students will make this item in Gen A. 1 ea.
Amazon | Harbor Freight | Home Depot | Lowe’s | Just kidding, you should already have it. If you don’t or haven’t made one, check with your instructor and see about fabricating it.
Magneto Timing Light **Note (Aircraft Spruce #12-16901 or equivalent) Students should make this item in Gen B.
**Note: Some students may be starting the program out of typical sequence order, if they have not had a specific General Class that they would have made one of the required tools consult the Powerplant instructor prior to starting the Powerplant Quarter for guidance. For students who do complete these projects during General take care to assemble them to the highest quality, to prevent having to open purchase them due to inaccuracy.
