Blowdown Tube Question, Valve Blew
Thread Starter
Teching In
Joined: Nov 2007
Posts: 42
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From: Issaquah Wa
Blowdown Tube Question, Valve Blew So I was out in my car today and just got my bottle filled. I had to switch all the fittings from my old valve into my new one. So I was out cruising after it got filled and hit 900psi when the saftey disc blew so all the nitrous went out the blowdown tube. Now I was super careful putting everything on this time since last time I broke Nitrous Outlets pressure switch by overtightening it. What needs to be done to fix my bottle? I am about to give up on nitrous, meth seems way easier
I have seen a ton of blown burst discs when filling bottles at the track.
Here is what I've seen happen:
If you overtighen the fitting it will seal, but will burst at a much lower pressure since the disc gets 'pinched' They will blow as low as 900 psi, which totally sucks since they blow when the blottle is nearly full unloading it contents while I'm 12" away from it.
Once that fitting is overtightened once, you can not replace the disc and keep the fitting. The fitting gets mushroomed and needs to be disposed of. If you try to put a new burst disc on the same fitting it will damage a new disc even if torqued down properly, and blow at a low pressure again.
If you replace the BDT fitting, with a new disc, and torque it down to the reccomended torque (which I can't remember off the top of my head, but I know its pretty low) you will be trouble free.
Vinny
Here is what I've seen happen:
If you overtighen the fitting it will seal, but will burst at a much lower pressure since the disc gets 'pinched' They will blow as low as 900 psi, which totally sucks since they blow when the blottle is nearly full unloading it contents while I'm 12" away from it.
Once that fitting is overtightened once, you can not replace the disc and keep the fitting. The fitting gets mushroomed and needs to be disposed of. If you try to put a new burst disc on the same fitting it will damage a new disc even if torqued down properly, and blow at a low pressure again.
If you replace the BDT fitting, with a new disc, and torque it down to the reccomended torque (which I can't remember off the top of my head, but I know its pretty low) you will be trouble free.
Vinny
Launching!
Joined: Sep 2007
Posts: 268
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same thing happened to me filling it for the first time.the disk blew while filling it.i told the guy i torqued it to 15 lbs. like in the instructions said. i guess the torque wrench was off.so it cost me 65.00 instead of 42.50 to fill it.he told me to just snug the fitting next time.so i let him put in the new disk and tighten it.working ok so far.if it does it again, i will be sure to change the fitting like the previous post said.
