Nitrogen as an inert propellant

For all pcp's and springers. Tuning, repairs, pellets, show and tell.
pickle
Stihl pickled
Posts: 435
Joined: 27 Feb 2016, 15:03
Location: UK, Mid Essex.

Nitrogen as an inert propellant

Post by pickle » 01 Jun 2016, 21:15

I remembered recently seeing a bit of a post by Rodp about nitrogen being used as a propellant. Is there any reason why it cannot be used (purged) to top up PCP's. I do not have a clue but on seeing a table in my book referring to work carried out by Cardew and Cardew on this very subject matter, Nitrogen seems to be, on the face of it, an alternative and possibly cheaper option. Nitrogen appears to have much the same density as air, is totally inert and less corrosive (I think) and could revolutionise the poor back up some of us experience from time to time. Why aren't we using it in our PCP's. What say you.

phoenix
BRUCE ALMIGHTY
Posts: 4754
Joined: 09 May 2012, 14:40
Location: Aberdeen

Re: Nitrogen as an inert propellant

Post by phoenix » 01 Jun 2016, 23:20

Cost
Air is around 80% nitrogen already, the cost of separating it from the other 20% would make filling PCPs much more expensive.
As an aside, I have a pal who used to own a diving shop which also sold air rifles.
They filled a non FAC PCP air rifle with Helium instead of air and the muzzle energy increased to a point where the MV of 22 pellets was way over the speed of sound.

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

User avatar
rodp
A bad influence
Posts: 4160
Joined: 09 Mar 2012, 22:49
Location: The Black Country

Re: Nitrogen as an inert propellant

Post by rodp » 02 Jun 2016, 16:56

It's actually fairly cheap Bruce if you use an industrial size cylinder, mine hasn't been refilled in over 4 years (although I don't use the pcp's much I will admit)
Theoretically there should be zero corrosion (no oxygen), a more consistent pressure and therefore muzzle velocity and cheaper than dive shops filling cylinders :thumbup:
"Land Rover, the worlds best 4x4 by far"

"Argo, a great 8x8"

pickle
Stihl pickled
Posts: 435
Joined: 27 Feb 2016, 15:03
Location: UK, Mid Essex.

Re: Nitrogen as an inert propellant

Post by pickle » 02 Jun 2016, 19:05

I have to say that Helium passed me by and is not one of the gases mentioned by Cardew and Cardew in Chapter 12 - Efficiency. They worked with Air, CO2, Argon, Butane, Freon 22 (not very friendly but what a cleaner), Nitrogen and Town Gas. Well rather them than me. I like the sound of Helium (unknown quantity). Nitrogen according to their findings, was pretty much on par with compressed air muzzle velocity wise. Am not any sort of authority on the matter by the way and you would have to read the chapter. Hang on though - have just realised (re read) that they were using a 'springer engine' of their own design developed purely for experimentation - not a PCP. So where does that leave my post? Well nice one Pheonix and Rodp, thank you guys for your input, am now minded to find out more about gases as Nitrogen is possibly a red herring here. I need more information to storm the forlorn hope. Helium - yummy.

phoenix
BRUCE ALMIGHTY
Posts: 4754
Joined: 09 May 2012, 14:40
Location: Aberdeen

Re: Nitrogen as an inert propellant

Post by phoenix » 02 Jun 2016, 19:31

The main advantage of Nitrogen over air is the lack of water vapour - which eliminates corrosion problems.

Cheers

Bruce
LAND ROVER - THE WORLD'S WORST 4X4 BY FAR

User avatar
rodp
A bad influence
Posts: 4160
Joined: 09 Mar 2012, 22:49
Location: The Black Country

Re: Nitrogen as an inert propellant

Post by rodp » 02 Jun 2016, 20:29

Forgot that bit Bruce, but yes, Nitrogen is "dry".


Pickle, one of the main reasons I use nitrogen, apart from the above, is it's easily available and there seems to be "less interest" in it from the manufacturers / suppliers :shh:
"Land Rover, the worlds best 4x4 by far"

"Argo, a great 8x8"

pickle
Stihl pickled
Posts: 435
Joined: 27 Feb 2016, 15:03
Location: UK, Mid Essex.

Re: Nitrogen as an inert propellant

Post by pickle » 03 Jun 2016, 17:26

If Nitrogen were a cheaper substance then it might prove ideal. Nitrogen is toxic in a confined airless space but then so is petrol if you leave the top off. Petrol immolates, Nitrogen does not. See if your motor mower starts on Nitrogen. N can be had in 20 litre bottles from BOC at 3000 psi or at your local garage (ha ha) to pressurize your tyres - wonderful. By the way N is classed as an entry gas suitable for for euthanasia in some countries but is sold watered down as a balloon gas - pump up your balloons on the street corner in downtown Dallas or New York et al. Apparently the Yanks stick some sort of substance on the inside of party balloons to make the balloons more buoyant and floatable and cheaper to fill so using less N. Isn't it a wonderful world. Balloons and their type kill more animals in the oceans than other toxins - actually not true ( well they do kill birds, turtles and anything else that tangles or tries to eat them) and David Cameron and the Labour Party just love balloons to celebrate. What a bunch of twats.
Last edited by pickle on 15 Jun 2016, 14:56, edited 1 time in total.

User avatar
rodp
A bad influence
Posts: 4160
Joined: 09 Mar 2012, 22:49
Location: The Black Country

Re: Nitrogen as an inert propellant

Post by rodp » 03 Jun 2016, 17:40

Sent you pm Pickle :thumbup:
"Land Rover, the worlds best 4x4 by far"

"Argo, a great 8x8"

User avatar
snoopy
Posts: 2620
Joined: 22 Jun 2012, 23:22
Location: NER NER LOL stoke on trent

Re: Nitrogen as an inert propellant

Post by snoopy » 23 Jun 2016, 13:20

basicaly, from the inviroment side it doesnt realy want to be realeased into the atmosfere...too much things starts dying lol.
'who is that masked man? its the kemosabby der..the bloody injun tells you every week!'

User avatar
Ooops
Posts: 266
Joined: 29 Dec 2013, 06:28
Location: Hampshire but on walk about some where hot

Re: Nitrogen as an inert propellant

Post by Ooops » 23 Jun 2016, 13:56

The gas plants, that I've come across, that were producing breathing oxygen were storing nitrogen as a waste product from that process.
I can't remember the exact cost but it was some thing like equivalent of fiver for a J size ....... where as helium, not that you'd want to use it, was about
£130....... just saying
The artist formerly known as Jethro

Post Reply