How often does something like that happen?

Get everything hooked up and installed. Do three small pressure tests to find and seal leaks, get them all sealed up. Third time you open the bottle, you hear it all pressurize and about 10 seconds later pssst, the main -4AN feed line ruptures just 6 inches from the bottle. Looking at the gauge before the rupture, there appeared to be between 600 and 800 PSI (bottle WAS full, but cold).

As soon as the line ruptured, I got out of dodge. I didn't want frostbite or to suffocate. It took the bottle maybe 40 seconds to virtually totally empty in the car. Luckily the doors and hatch and all were open.

What can cause that to happen, anyway?

 

Bad line, perhaps it had defect or small cut just waiting to blow. If it was just a nick, and there's enough length, you could have it re-terminated. Personally, I wouldn't trust it though...get a new one. At $40+ a bottle it wouldn't take long to spend more than the line is worth.

 

That's a freak deal. If teflon line gets kinked by someone it could cause enough stress to cause that, but I have never heard of teflon line rupturing before. I have however seen it leak from a pinhole. The pinhole was caused by not having an effective vehicle groundstrap and the line acting as one.

 

I'm running a 1/0 ground from the battery to chassis, and a 4 guage from the coil mounting bracket to the frame rail in addition to the stock ground wiring.

 

I wasn't suggesting that your car had bad grounds. Its just that was the only thing I have ever seen for sure cause a leak in teflon. If I were you I wouldn't even consider it happening again.

 

I thought about sheathing the new AN line with some heater hose, and letting it vent outside the car. I would think that running the AN line through a tube, clamping it at the top, and leaving the bottom open might help IF it ever happened again.

 

It certainly wouldn't hurt anything if you did.

 

Are you sure you are using the correct grade lines, rated for the 1000+ psi potential of nitrous? There are lines available with lower pressure ratings.

 

The line that ruptured was included with the NOS brand kit, so I would assume that it's properly rated for nitrous use.

All the other lines that are on the car are brand new NOS brand lines, so I would assume that they're ok for the pressure as well.

 

I would return the defective line to NOS for a replacement and ask them to compensate you for the nitrous refill. Sounds like poor quality control from them or their supplier. My friend and I have installed 5+ kits (NX) and have never experienced a ruptured line.

 

This is not a brand new kit. It was installed in another car for a couple of years, and then I moved it to my car.

When I talked to NOS about it yesterday, there was no mention of any warranty replacement. During the move to the new car, I ended up buying several new lines because I needed more length, and the line that ruptured was the only used line on the car.