NITROUS OXIDE ( nos / n2o ) advice forum

I have been leakproofing my system.

I have a 1meter Goodridge preformed an3 build a line, a bottle heater and Won Gauge on two Tees followd by another an3 build a line to the front (4 meters worth!).

I can pressurise the system and go round with the leak detector spray and see no bubbles anywhere but if I turn the Maxflow valve on, then off again and load the sytem up to 800 psi the pressure will drop to 200psi over 2 hours then stay there (checked after 7 hours).

The actual nitrous in the lines is a drop in the ocean to what I use while spraying so is it worth further investigation or is that the norm for braided lines?.

System works perfecly when in use.

Hi

I have AN braided from my big twin bottles and NO its not normal...lol

You have a leak..... more testing i suggest...

All the best Brett

Cheers, more testing it is then!. How long does yours hold pressure after the valve is shut.

Hi

Days or weeks..... I normally use my twin purge to clear the lines....

But if its not holding for at least 3 or 4 days....you have a leak....

Heat the bottle and try leak testing at 950 psi...should be easier to find....

All the best Brett

Actually its your situation that's NOT normal Brett, as ALL the braided hoses we've ever used/tested LEAKS and that's one of the reasons why I don't like it.

When the ends are fitted (crimped or otherwise) the braided strands deform the inner sleeve and cause MICRO leaks.

If you soak the entire braided hose with very soapy water, you'll see MICRO bubbles peculating slowly from every intersection of every strand.

Hi Trev

Thats probably because when Dave fitted my braided pipes , I seem to remember him taking a long time and a lot of effort to get the ends right...

All the best Brett

I have braided sections on my system Keith. Only about 5 feet from bottle to Y piece, and then 2 more braided lines of 20" from the Y to the pulsoids. If i pressurise the system to 800 psi I see a drop to about 500psi over 3-4 hours depending on ambient temperature. And then it remains stable. I have leak tested until the cows come home. I've used various sprays and even good old fairly liquid in water with a paint brush which i use at work for low pressure gas leak testing. I've never seen a leak on the 4 braided joints. But there is one somewhere. It does not bother me bacause I only turn the bottle on just before a run on track. And the bottle gets turned off as part of my end of run procedure. Normally just after the finish lne where I shut off the 3 switches and turn the bottle off while I'm slowing for the exit gate.

I have had the system totally leak free from a fresh build with braided lines. But within a few months I always get the slight seeping pressure loss.

Perry

Trust Dave to get one made 'almost' perfect Brett.

Perry if you do those checks up the full hose length you'll see the micro-bubbles I described leaking out from the braiding somewhere. It doesn't always leak near the fittings, it can find it's way between the SS braid and the PTFE sleeve without showing itself as a leak for a good distance, before finding a way out and even then it tends to look like a VERY SLIGHT foaming action rather than a leak.

Will have one more go with the leak detector spray then call it a day, when racing the valve will be on in 10 min stints so losses will be negligible as Perry says.

I chose an3 due to the 3.5mm id and my long pipe run, plus used to working with it on the bikes.

Stripped the car yesterday to fit a clutch and the nitrous was the easiest bit to deal with!.