Refilling your Nitrous Oxide Bottles and Cylinders (NOS tanks) at
home - How?
Nitrous Oxide Tank / Cylinder or Bottle Refilling,
How its done!
Vets, Manufacturing Industry,
Welders (welding suppliers), Aerosol manufacturers,
Hospitals, Dentists, Breweries and dozens of others all use Nitrous
Oxide for various things. Ask them if they will supply you as
well? Its often the cheapest option.
Or ask them where they get their
Nitrous Oxide locally?
This is often the
best way to find out. I used to buy my Nitrous
at very favourable rates in 100lb cylinders from Kingston Medical Gasses in Hull in the UK but they have
now disappeared unfortunately! There's always plenty of places
advertising online if you get stuck. But its likely you also
have someone in your hometown that offers a refill service
like a tuning shop and its quicker. Don't worry there
are more options.
It is also possible to buy
Luxfer cylinders complete with
VTI Diptube valves at reasonable rates from
www.nitrousoxidesupplies.co.uk as well as Nitrous delivered.
You can rent a large refill
cylinder from your local branch of Lynde Gas, Contact the Head
office 0121 500 1000 for your local supplier. There is
another large UK supplier but the name eludes me at the
moment! (This is UK
only of course, you well need to find your own supplier in
Then you can refill your own
bike/car at home as needed. This is the best way, if not quite
You can also try your local branch of "Air Products" or
don't tell them it is for automotive use because they seem
to have a completely irrational fear of using it for this
purpose! Depends who you speak to and how you put
it... And remember it has a bad rep for other
reasons too! (some people "sniff" the stuff to get high).
Or you can try
guy, he will deliver, pick up, and supply your gas in the
Refilling your own
bottles from a large rented one at home
So you have sorted out a supplier
of refills or somewhere to get your small car/bike bottle
filled? That OK then!
But if like me you find it
inconvenient to keep getting your bottle filled, or cheaper
to buy bigger quantities then you will need to fill your
own! Find someone such as Linde (Above) to "rent" you
a huge "fill" bottle (100lb or above) that they will collect
/ deliver to and from your home. Then you can fill your
smaller bottles from this.
My bike's) had a small 2 1/2lb
polished alloy bottle, and my Cars had 15lb bottles. These were
sometimes every evening (I am addicted!) especially on
I didn't rent a big bottle as most
people do, but used an old Argon bottle (I think) 100lb+ that was
found at the back of my mates workshop! This is rated at
much higher pressure than needed for Nitrous, so safe. Kingston
Medical Gasses (now closed down sadly!) used to fill this
for me when I needed it very cheaply!
All you need to
fill your own bottles is:
to accurately weigh the empty and full bottles.
loop (a bit of pipe to connect the full bottle to the
empty one) - this can be cheap 4mm Nylon, with some
simple end fittings.
NOT need a pump!
1. Check out the big bottle
you are filling from. Does it have a siphon tube inside of
it? Most do not. You need liquid Nitrous so you may
need it upside down or at least angled down by 15 degrees.
Bottles or Cylinders with siphon tube generally have a white
painted line on the side to show this.
If it has a siphon tube leave it somewhere on the floor
or preferably higher up and upright! With the valve
at the top. If it's higher up than the bottle to be filled
it will flow more easily into it. Nitrous flows from warm to
cold, and from higher to lower! Remember that its
Remember you want the
LIQUID out of it not the gas so if like most bottles it DOES
NOT have a siphon tube, this fill bottle MUST be upside
down! It does not need to be completely upside down, but the
valve will need to be a little lower than the "bottom" of
the bottle. Maybe 15 Degrees is enough. However you organise
this, it must allow the LIQUID Nitrous to come out not the
2. Connect a pipe (small
bore nylon 4mm O/D, bit of braided hose, or whatever you
like that can take the 1000 psi that will be in it! that is 1 to 2
meters long to the valve. Ready to connect up to the bottle
you intend to fill up - but don't connect this yet!
3. Take the EMPTY
bottle you need to refill and weigh it! Write it down.
Learn it, and in any case it should be stamped on the
bottle... But you MUST KNOW IT!
Don't get it wrong!
4. Now stick it in your
deep freeze! Preferably the night before. Seriously. You
need the bottle you are filling up to be
than your big fill bottle is. Because you need
Nitrous! Since they will be connected together, the
pressure in both will be almost the same.
to be filled will be lower down physically, (on the floor?)
so its pressure will be slightly higher when the valves are
opened. The pressure and temperature difference will ensure
that your bottle will fill properly with liquid when you
open the two valves. If its not cold enough filling will
stop or really slow down. Use your scales or weighing
device to see this.
5. Take you ice cold
bottle out of the freezer, and connect it up to the big fill
bottle that's waiting! Lay it on your "Bathroom Scales", or
Spring Balance so you can see the weight...
6. On the bottle will be
stamped the "full" weight, or the amount it holds... Open
the valves, you will hear the Nitrous rushing in. When the
CORRECT amount of Nitrous has filled your once empty bottle
STOP! And disconnect.
Its actually very easy to get
say, 3lb in a 2.5lb bottle or 18lb into a 14lb bottle, but
its not big and its not clever! The extra space is
DESIGNED to be there! Its expansion space and its
You don't want to see what happens if a blow off /
overpressure valve fails to work...
Your house will be no more...
You will be no more!
bottle stops filling before you get your 2.25 Lb in it
then turn off valves. Disconnect the small bottle.
Vent vapour to atmosphere until the bottle is ice cold!
Not liquid! Vent gas only.
It will get to extremely cold
doing this as the liquid inside tries to turn to vapour.
Very quickly. You may lose 10 percent of the contents doing
this though. But it works and its faster than the freezer.
Reconnect and continue filling.
the term NOS is incorrect as this refers to an specific
company (called Nitrous Oxide Systems, in the US)