Sometimes even a truck doesn't cut it. Five or six years ago I went to my usual gas supply place to get a small bottle fill. It was a shiny new bottle that I used on my kegerator. They usually didn't have 2.5# on hand for exchange, and if they did it would be some ugly, heavy steel one. So I opted to have them fill it.
Now the problem with filling a 2.5# bottle is that the tare weight is less than the weight of the fill hardware, so getting an accurate fill can be problematic. This time I got a real big overfill. It was a really hot summer day. I had a King Cab Ford at the time.
I strapped that bad boy in the back seat, turned up the a/c and headed out on the Interstate for the 20 minute drive home. Somewhere around 80 mph I heard a loud bang followed by serious fogging in the cabin and some trouble breathing. I knew immediately that the bottle had discharged, and hit the gang switch to open all the passenger windows plus the rear window pass- through to vent the CO2.
I've gone through training in hyperbaric chambers for rapid decompression. The noise and condensing moisture, plus the subtle signs of hypoxia. Not what you want to experience on a busy highway.
What had happened was an overfill and high ambient temperature in my truck. The internal pressure exceeded the burst pressure of the OPD. Now I do only bottle exchanges. I figure if a CO2 tank can handle the jostling on a delivery truck and sit in a warehouse for a period of time, it'll survive the drive home....in the trunk.