Nitrous leaks thru washer/gasket on valve...

[chevota]

I use white (teflon?) gaskets sold by NOS between my valve and AN adaptor, is there a better one out there?
When I turn the bottle off the pressure in the line will bleed from 1-12 or so hours, I assume it's this gasket since the bleed time changes every time remove/reinstall the adaptor. This gasket setup seems like a real poor design to me, is there something better out there? Rubber O-rings maybe??
If not I'm thinking of tapping the valve and installing a -4 AN directly to it.

 

[madhatter210]

I don't think I have ever seen that gasket to be honest. I always wrap the npt threads in my system with teflon tape. It keeps you from having to really reef on the thread alot trying to get a seal. Also, if its leaking after use its leaking during use. Are you sure its that adapter that is leaking, could be a line fitting anywhere from the bottle to the nozzle. And just a question, how do you know your leaking out? What kind of set-up are you running btw

 

[chevota]

Really? I thought that adaptor/gasket deal I have was all there was out there.
I use teflon tape on the other fittings, but the nitrous valve on the bottle to the -4 adaptor is what I'm talking about.
I know it leaks because after I turn off the bottle I'll hit the purge later to see what's left. Sometimes I have 1/2 left the next morning, sometimes nothing after only an hour.
And yes, that means its leaking when the bottle is open and wasting my precious juice for nothing.
My system is a mix of misc parts. Cold Fusion solenoids, a single NOS soft plume nozzle, and home spun wiring and switches. 20' of -4 between tank and solenoid, 18" of -3 solenoid to nozzle.

 

[rys]

Really? I thought that adaptor/gasket deal I have was all there was out there.
I use teflon tape on the other fittings, but the nitrous valve on the bottle to the -4 adaptor is what I'm talking about.
I know it leaks because after I turn off the bottle I'll hit the purge later to see what's left. Sometimes I have 1/2 left the next morning, sometimes nothing after only an hour.
And yes, that means its leaking when the bottle is open and wasting my precious juice for nothing.
My system is a mix of misc parts. Cold Fusion solenoids, a single NOS soft plume nozzle, and home spun wiring and switches. 20' of -4 between tank and solenoid, 18" of -3 solenoid to nozzle.

You can use spit, or leak detector to find the leak.

Also, you should not use Teflon tape, only Teflon paste. Teflon tape can flake off and go down the line then lock up your Nitrous solenoid.

-Brian

 

[chevota]

So I guess I'm the only one with this problem?

ryz:
What kind of paste are you using? I've tried sealant from ARP and Loctite on several CO2 bottles w/o luck so I didn't waste my time trying it on the nitrous.

 

[rys]

So I guess I'm the only one with this problem?

ryz:
What kind of paste are you using? I've tried sealant from ARP and Loctite on several CO2 bottles w/o luck so I didn't waste my time trying it on the nitrous.

I used to use the Permatex Teflon paste, but someone on some website mentioned that the industrial teflon paste like you might find in the plumbing isle at Home Depot is the stuff to use.

Never had any trouble with leakage.

Keep in mind that nitrous pressure is based on temperature. If you pressurize the line at 80 degrees ambient, you close the bottle, and the temperature drops to 60. The pressure in the line will be less than at the point where you closed the bottle.

Also, did you consider that you may have a bad line, or that the nitrous may be escaping somewhere in the line (pinhole leak)?

-Brian

 

[madhatter210]

I used to use the Permatex Teflon paste, but someone on some website mentioned that the industrial teflon paste like you might find in the plumbing isle at Home Depot is the stuff to use.

Never had any trouble with leakage.

Keep in mind that nitrous pressure is based on temperature. If you pressurize the line at 80 degrees ambient, you close the bottle, and the temperature drops to 60. The pressure in the line will be less than at the point where you closed the bottle.

Also, did you consider that you may have a bad line, or that the nitrous may be escaping somewhere in the line (pinhole leak)?

-Brian

Paste is nice for fittings you probably won't remove to often. I should of been a little more clear above what I'm using, its teflon tape but its yellow and propane/vapor rated and does not flake( haven't had a leak yet). And like the paste you can find it in home depot in the stove/hvac section.And like mention it could be a line or any fitting from the bottle to the purge.

 

[chevota]

Ok, I sprayed soapy water on the bottle adaptor fitting and that is where it's leaking. I'm sure it's that stupid teflon gasket. I had a different adaptor that wasn't chrome plated that sealed better, but I damaged it.
I think the teflon washer trying to seal against the two chrome plated surfaces is too much to ask.
I guess I'll install an AN fitting directly to the bottle since there doesn't seem to be any other options?

 

[DSMJim]

Ok a few things here.

1) DO NOT USE TELFON TAPE OR PASTE ON ANY -AN fitting. THey seal on their own. That is what the angled end is all about. Just put it in without any sealer and it will seal. Thats's the whole point of an AN fitting is it can be installed and removed without having to re-seal it all the time. This is also why it's leaking because your not making proper connection between the line and the AN fitting. Look inside the line that hooks upto the AN fittings and you will see they are angled inside the same.

2) When you turn the bottle off and leave the car over night the nitrous will bleed off eventually, you can not store 1100psi in all those lines and seals for ever. It will eventually bleed out of the lines, there is nothing you can do. It's so little and so slow that it's not causing you to lose anything while your acctually using the nitrous.

 

[madhatter210]

Ok a few things here.

1) DO NOT USE TELFON TAPE OR PASTE ON ANY -AN fitting.

Agreed, I wasn't trying to promote the use on -an fittings only the npt. I have three of them in my setup. me= "I always wrap the npt threads in my system with teflon tape."

 

[loweperf]

What brand of bottle are you using? NOS bottles use the teflon washer your talking about. NX use a different adapter altogether.

 

[chevota]

loweperf:
Thank you, this might be what I need.
I see it here:
http://www.nitrousexpress.com/Catalog/2005/bottle_access.pdf,
but I'm not sure how it seals. I don't see a washer or O-ring, is it metal to metal?

 

[loweperf]

Yes it's metal on metal. Tha ball end goes into the hole on your valve and seals it. If you using an NX bottle this is the type valve it will have.

 

[chevota]

My valve is made by Sherwood, I bought it at a welding shop. It's appears to be chrome plated brass?
I'm not sure if an NX valve has a different shape to work with this guy or not? Mine has a hole with a 90 degree step to smaller hole, so the ball end would be sealing against a fairly sharp 90 degree angle.
Maybe I could send or post a picture if my description doesn't make sense?

 

[loweperf]

A pic might help. Did you get any kind of paperwork with the valve? If so does it say what type valve it is? A 660 type valve uses the teflon washer. A 326 type valve uses the NX type ball adapter. Sherwoods web site list it as a 326 for nitrous oxide use. Did you ask for a nitrous valve? http://www.sherwoodvalve.com/pdf/techspec.pdf

 

[chevota]

Stamped on the side of the valve: "CGA 660"
(Photo attached)

 

[madhatter210]

You know what though, that is npt. You can wrap that with teflon or use paste. If I remember correctly your leaking from the npt to -an line adapter.

 

[chevota]

It's does kinda look like a taperd NPT in this pix, but it's not. It's 1" x 14 threads per inch. The NOS "Bottle Nut Adaptor" threads on fine, just doesn't seal for crap. (will I get booted for saying crap here?)

 

[loweperf]

That's a 660 type valve and should use the teflon washer style bottle nut. Make sure your surface is flat and maybe try a new gasket. All 64 lb. bottles we fill from are 660 valves and in 3 years we have not replaced the washer yet.

 

[chevota]

So I guess this means the NX deal won't work with this? Dam, so I guess I'll need to drill and tap it for a -4 x 1/4NPT fitting. I hate to do that, but I guess if there are no other options...
My CO2 tanks had a similar bs flat washer for sealing and they leak too, but I found some O-rings to replace the flat washer and the problem is solved. My other tanks; O2, Argon, Acetylene, and Helium never leak. I can leave them off for weeks and there is still full pressure at the gauge.

At $5 a pound and 1 to 1-1/2 hours of personal time per fill, I'm not going to let this stuff just leak out. I hope my guy can fill the tank with the -4 installed, I'd really hate to pull it out every fill.