NITROUS OXIDE ( nos / n2o ) advice forum

So my 34 kg bottle turned up today from nitrous supplies . I've made myself an inverted stand. Ordered my decant kit. Im using 20oz bottles. I'm a bit worried about over filling them. How long would I put my bottles in the freezer for?I will always empty bottles and leave valves open while chilling. How long should I have the gas flowing from the mother bottle to the little one. If I did over fill I let out excess but do I invert bottle and let out gas or keep upright and let out liquid. Thanks in advance for any help. Dave

It fills so quick.....no chance to stop at the right point. maybe about 5-7 seconds and its done.
I use also to fill 20Oz to 2.5lb bottles and got a feeling to hit on ~ 50 gramms.
You see the outside of small bottles get wet when the liquid in the inner raises. look at this effect when filling.

I only use WON valves with the SPRV and recomend them to anybody. No more bursting your money .

No need to empty the small bottles and waste nitrous, works anyway when they are frozen.
In winter i placed them just some time outside and it flows fine.
Depends more of ambient temperature of your motherbottle. (the hotter outside the more pressure you have)

Doesnt matter how you let "overload" out. 50gramms are 50 gramms liquid or gas.

Dont leave empty bottle valves open when you put them in the freezer Dave. There is a risk of allowing air and moisture into the cylinders. If you decide to blow them off to make sure they are empty and then close the valves while they are in the freezer for however long you choose to leave them in there, the bottles may develop a slight negative pressure.

If your big bottle is at say 20C and the small bottles are at say 0C the fill wont take long. This is where a set of digital scales will help.

You need to have the empty bottle on the scales with the fill line connected and the bottle valve open. When you have the fill line connected you will then zero the scales and slowly open the valve on the big bottle until liquid starts to flow. You can then read off how much weight is going into the small bottle.

I sometimes use my vac pump to pull a negative pressure on my small bottles at room temp before I fill from a big one at my mates place.

I'm just about to buy a big bottle from Simon at nos supplies. What are the latest prices ?? Is it still £90 for a years bottle rental? I hear they now charge for collection and delivery ? What is the current price for a big bottle ?

Pel

Thanks both of you for the help. Much appreciated thanks. I'm going to fill my bottles for my first time tomorrow. So excited. And if it's not raining I expect they will be empty by the evening lol. I dont know how expensive n20 is to buy by the oz or lb . I got my big bottle because it's so much easier and quicker to fill up in my garage. Nitrous supplies prices are. Gas (34kg) - £220.50+VAT
Rental - £80+VAT
Delivery and/or collection - £25+VAT . Simon was very helpfull getting an account opened for me and it was quick delivery. Good service.
As it's only about 10c in my garage I will have bottles in freezer for 4 or 5 hours to get them good and cold. I might heat the garage up a bit for an hour or do to get the bottle temp up couple degrees. I will let you know how I get on.

I see Perry beat me to the post.

Yep sure did order my decant kit from you. It is the cheapest one around and and much as possible I will get your won products. Main dealer service and quality parts at back street garage prices.
Hmm I wonder if the wife will let me have the mother bottle in the house to keep warm lol.

Put it in with the hot water tank and tell her it's an expansion tank.

Pmsl. She would probably go for that. Anyway no need she has let me put it in the corner of our spare room. Which is where my bike spent the winter. Bless her.

Well I managed to refill both bottles today. Scared myself though. When all was connected I turned main bottle on to purge the air and the line blow off the fitting with hell of a bang. Certainly woke me up lol. Mother bottle was 20c and my 20 oz bottles were 5 c. When up to 18 oz no problem and then stopped. So I left line on and shook the bottle a bit and hot bang on 20oz in both. I'm sure after a few fill fills it will be easy as I get the hang of it. It's its scarey stuff first time, worrying about burns and pressure and stuff especially as it's in the house in my spare room. All good now and fitted back on my bike. Just need a nice dry day now to empty them

Excellent and a little scare the first time round is a good thing as it makes you respect the process more.