The AirGun Guild

General Category => Airgun Tanks, Compressors and Filling => Topic started by: Monkeydad1969 on February 02, 2016, 09:10:46 PM

Title: Nitrogen.
Post by: Monkeydad1969 on February 02, 2016, 09:10:46 PM
Has anyone done a nitrogen setup yet?  Curious to see what it will cost to set up.
Title: Re: Nitrogen.
Post by: Dcorvino on February 03, 2016, 05:12:58 AM
Has anyone done a nitrogen setup yet?  Curious to see what it will cost to set up.

Interested to know as well

Dave
Title: Re: Nitrogen.
Post by: Truckr6969 on February 03, 2016, 02:55:41 PM
What I was told by air gases was 185 for 5 year lease and 167 per refill for 6kpsi 305cf bottle
Title: Re: Nitrogen.
Post by: Monkeydad1969 on February 03, 2016, 06:58:53 PM
Thanks, keep the info coming members.

Joe
Title: Re: Nitrogen.
Post by: Dcorvino on February 03, 2016, 07:42:12 PM
Thanks for posting the price list.
Wonder about finding a regulator and gauge set up for it.

Dave
Title: Re: Nitrogen.
Post by: Truckr6969 on February 03, 2016, 08:33:14 PM
Joe from airtanksforsale.com has a set for 6k nitrogen tanks
Title: Re: Nitrogen.
Post by: Monkeydad1969 on February 03, 2016, 08:35:16 PM
I saw that.
Title: Re: Nitrogen.
Post by: Doc on February 04, 2016, 12:22:41 PM
Used them for years. Company I worked for had 3ea 6000 psi bottles. I filled directly off the bottle no reg until later. Go slow and pay attention. Your better off to buy the bottle and have it filled when needed.     
Title: Re: Nitrogen.
Post by: Tinpan on February 23, 2016, 09:03:45 PM
 Could a guy feed a shoebox with the  nitrogen tank when it gets below 3k as long as you keep the psi to the shoe box below 90psi,it would be clean and dry????
Title: Re: Nitrogen.
Post by: Hobbyman2007 on April 06, 2016, 01:42:10 PM
Could a guy feed a shoebox with the  nitrogen tank when it gets below 3k as long as you keep the psi to the shoe box below 90psi,it would be clean and dry????
Absolutely , once your tank is below the 3000psi mark ,plumb it into the shoebox and fill a guppy tank from that. That way you could use the tank(nitrogen)  all the way down to 85 psi ( enough to feed the shoebox)
The only downside is having to buy a second tank good for 4500 psi.

I have a question regarding the nitrogen for those in the know . How much fps would be lost as compared to compressed air at the same PSI?
Title: Or... Helium?
Post by: Alan on April 06, 2016, 03:22:53 PM
I have wondered more about helium than nitrogen. Obviously, some of the same issues (pressure, regulation, etc.) apply, but the gas itself is somewhat lighter. That fact, should allow faster velocities at any given pressure.

And, if you get crazy, you can breathe in some helium, and talk like Donald Duck! Just kidding!
Title: Re: Nitrogen.
Post by: Monkeydad1969 on April 06, 2016, 06:09:16 PM
Could a guy feed a shoebox with the  nitrogen tank when it gets below 3k as long as you keep the psi to the shoe box below 90psi,it would be clean and dry????
Absolutely , once your tank is below the 3000psi mark ,plumb it into the shoebox and fill a guppy tank from that. That way you could use the tank(nitrogen)  all the way down to 85 psi ( enough to feed the shoebox)
The only downside is having to buy a second tank good for 4500 psi.

I have a question regarding the nitrogen for those in the know . How much fps would be lost as compared to compressed air at the same PSI?

As from I know and have read, you gain fps with nitrogen.  Not sure how much, but enough to notice.
Title: Re: Nitrogen.
Post by: rsterne on April 08, 2016, 05:20:56 PM
The gain with Nitrogen is small but measurable....

Bob
Title: Re: Nitrogen.
Post by: nappyman on May 30, 2016, 11:08:08 PM
Price and setup cost depend on who you are and were you live.

I'm a moble welder, I get a discount at the welding supply store. I pay about $70.00 a month for 2 (k) oxigen bottles, 2 (#4) acetylene bottles.  It would be around $100 for anyone just coming off the street. Mind you, that's just the rental, refills are about $20, $30 respectfully.

For two years I also rented a 6K and keep it in the garage to fill my 88cuft or guppy tank. 
Cost: Joe B 6k reg $145-160 don't remember but it was not cheep.
          6k rental fee: it went from $60 a month to about $100 a month. Gave it up a year ago was not worth the price.
            6K refills were about $110
             6K bottles weigh anywhere from 200-300 lbs.
Without my discount, it would be at least 1/3 more

I have heard it can be got cheaper in other regions of the country if they will even rent to you,  but here I California
My price was about as good as you can get.
Title: Re: Nitrogen.
Post by: ShakySarge on May 31, 2016, 04:40:04 AM
If you already have a good fill assembly rated at the proper pressures such as found at MAC1. All you need to do is go to a local AIRGAS or similar location and they can sell you two simple pieces that simply go where the SCBA/DIN adapter and shaft would go on the cross connector. Simple as that. No need to go running to Joe over anything. I am partial to Airhog anyways.

(http://i1070.photobucket.com/albums/u499/inaslump1/Airguns/Tanks%20and%20Fill%20Accesories/IMG_3233_zpsf7bc93d4.jpg) (http://s1070.photobucket.com/user/inaslump1/media/Airguns/Tanks%20and%20Fill%20Accesories/IMG_3233_zpsf7bc93d4.jpg.html)

After you have that simple set-up, then you can buy or rent a 6K Nitrogen Tank. Good idea to have a buddy to help with unloading it as well. Some rent by the year, some by the month, some only sell them and they ALL charge for re-fills.

Matt
Title: Re: Nitrogen.
Post by: ncrary on May 20, 2017, 12:37:19 PM
I am looking into this.  My local welding supply quoted me $10 month rental, $200 to buy outright and $130 for refills.  Price looks good.  However, I am not a mathematician and no matter how many times I add, divide, or multiply, the numbers do not make sense.  How many times can I fill a 88 cubic foot bottle from 3000 psi to 4500 psi from a 6000 psi 335 cubic foot nitrogen tank?
Title: Re: Nitrogen.
Post by: Alan on May 20, 2017, 03:44:00 PM
The way you shoot, you'll need to refill the beast about once a month! Geez, I thought I shot a lot of lead!
Title: Re: Nitrogen.
Post by: Christopher on May 21, 2017, 06:25:22 AM
ncrary said
Quote
How many times can I fill a 88 cubic foot bottle from 3000 psi to 4500 psi from a 6000 psi 335 cubic foot nitrogen tank?


The best I could figure  ??? (and believe me it was a struggle) it would be about 3.5 refills, but that doesn't take into consideration van der Waal's effect. Which basically says that at higher pressures your not really putting as much air in your tank (on a molecular level) as what your gauge is reading. I would imagine that it would have a more noticeable impact on the pressure drop from 6k-->4k than from 4.5k -->4k -->3.5k and so on....Trying to compute that (van der Waal's effect) into the equation is outside of my capabilities. 

Hopefully Bob will give us his input.

Hope that helps,
Chris
Title: Re: Nitrogen.
Post by: ncrary on May 21, 2017, 06:09:53 PM
Using the P1V1 = P2V2 relationship I come up with about 5 fills.  Mu guts tell me that is not the case, since I will not be filling from 0 to 4500 psi, but from about 3000 to 4500 psi.  My math skills have failed me.  I should have paid more attention back in 1964.

Help, Bob.
Title: Re: Nitrogen.
Post by: Christopher on May 22, 2017, 02:43:34 AM
Well, I had a time trying to find what the actual liquid capacity was on the 335 cu ft tank. I really only found one source online and it says that it has a liquid capacity of 50 liters http://www.cylsonic.com/cylsonic/Products/Understanding-UE/Cylinder-TypesSizes.htm (http://www.cylsonic.com/cylsonic/Products/Understanding-UE/Cylinder-TypesSizes.htm) ......Then Lloyd Sikes fill calculator states that an 88 cu ft tank has a capacity of 1442 cc's http://www.calc.sikes.us/2/ (http://www.calc.sikes.us/2/)...If your big tank has a fill of 6k and you will be taking it down to 4.5k that is the difference of 1.5k....on your 88cu ft tank you are going from 4.5k down to 3k, again a difference of 1.5k.....So if both are being drained 1.5k psi or 103.4bar, the ratio of fills will be determined by size......Thus the big tank is 50 liters (assuming the numbers from the above website are correct) 50 liters=5000cc and the smaller tank is 1442cc then it would be 5000/1442=3.46 fills

Chris

Edit: Modified to strike out wrong calculations, I came close to the right answer, but it was simply coincidence :-[
Title: Re: Nitrogen.
Post by: ncrary on May 22, 2017, 07:12:07 AM
Those numbers don't seem realistic somehow.  I would expect to be able to fill many more times than that.  Maybe my gut is wrong, and if it is, then nitrogen is definitely not the way to go.
Title: Re: Nitrogen.
Post by: jhm757 on May 22, 2017, 08:53:15 AM
My 6000psi Nitrogen tank costs me $100 a year to lease the tank, and $60 for a refill.

A tank lasts me for a year, and that is a lot of shooting, so total cost is $160 a year.

Only draw back is once it is under 4500psi you don't get a full fill on the 4500psi carbon fiber tank. but still lots of shooting left.

But it sure is nice to always have Nitrogen, and only have to refill once a year. I keep the tank strapped to a beam in the garage.

It is very heavy when it is time to take it in for an exchange. I imagine I could have the exchange delivered, need to look into what they charge for that.

Jim - jhm757
Title: Re: Nitrogen.
Post by: Christopher on May 22, 2017, 12:34:12 PM
ncrary said
Quote
Those numbers don't seem realistic somehow.  I would expect to be able to fill many more times than that.

It does seem off somehow, I would have thought it would have been much more as well. I'll definitely be the first to say that I could be wrong, as I admitted earlier it was a challenge to try to figure it out and math isn't my strong point either, but now I'm really curious.  I'll post a link for this over on the Ask Bob forum and we'll call in reinforcements 8) he'll get to the right answer I'm sure.

Chris
Title: Re: Nitrogen.
Post by: ncrary on May 22, 2017, 01:26:12 PM
My 6000psi Nitrogen tank costs me $100 a year to lease the tank, and $60 for a refill.

A tank lasts me for a year, and that is a lot of shooting, so total cost is $160 a year.

Only draw back is once it is under 4500psi you don't get a full fill on the 4500psi carbon fiber tank. but still lots of shooting left.

But it sure is nice to always have Nitrogen, and only have to refill once a year. I keep the tank strapped to a beam in the garage.

It is very heavy when it is time to take it in for an exchange. I imagine I could have the exchange delivered, need to look into what they charge for that.

Jim - jhm757

Jim,

That doesn't tell me how long it will last for me.  I need a hard number of refills you can get.  If you refill your 4500 psi tank once a month and I refill once a week, or maybe twice when I am out squirreling, then the nitrogen tank will not last as long for me.  So, with $130 refills here, I need to know how many times a year I would be refilling.  If the cost warrants it, I will get a compressor.
Title: Re: Nitrogen.
Post by: rsterne on May 22, 2017, 02:55:59 PM
Here is my answer to the PM I received on this, as I figured others would be interested....

The internal volume of an 88 CF SCBA tank is 550 CI, it holds 88 CF at 4500 psi.... The standard 6000 psi steel cylinder is a DOT 3AA-6000, and they have an internal (water) volume of 1.50 CF.... and are typically listed as 480 CF (sometimes called a 510 CF).... 6000 psi is 414 bar, so using Boyles, that should be (414 x 2383) / 1728 = 570 CF.... Using VanDerWaals for Nitrogen instead of using 414 bar, we use a factor of 322 (339 for air), so at 6000 psi it should contain (322 x 1.50) = 483 CF (509 CF for air).... so that 480 (510) CF is pretty close.... If your Nitrogen tank is a different size, or not filled to 6000 psi, then the calculations below are wrong....

The problem is, that both tanks contain fewer CF of air (or Nitrogen) between your fill and refill pressure than a linear relationship would suggest, due to the VanDerWaals effect.... The only real way to do this is to use the density of Nitrogen at the three pressures (6000, 4500, and 3000)....

Density of Nitrogen at 6000 psi = 376.1 kg/m^3
at 4500 psi = 310.1 kg/m^3
at 3000 psi = 225.1 kg/m^3

From that, we can calculate the weight of Nitrogen released from the large tank (assuming 1.5 CF internal volume)....

1.50 is 0.0425 m^3.... so at 6000 psi it contains (376.1 x 0.0425) = 15.98 kg. of Nitrogen.... and at 4500 psi, (310.1 x 0.0425) = 13.18 kg.... The difference is (15.98-13.18) = 2.80 kg. of Nitrogen released for a drop from 6000 to 4500 psi....

550 CI is 0.00901 m^3.... so at 4500 psi the SCBA tank holds (310.1 x 0.00901) = 2.79 kg. of Nitrogen.... and at 3000 psi, (225.1 x 0.00901) = 2.03 kg.... The difference is (2.79-2.03) = 0.76 kg. of Nitrogen required to fill it from 3000 psi back to 4500....

The number of fills is the weight of Nitrogen released from the big tank, divided by the weight of Nitrogen required to fill the SCBA tank.... (2.80 / 0.76) = 3.68 fills....
Kudos to you for coming up with 3.5 fills....  8)


Bob
Title: Re: Nitrogen.
Post by: ncrary on May 22, 2017, 04:37:13 PM
Thank you, Bob.

So, assuming I need to fill my bottle once a month on average for the year (so far I am filling it about once every two weeks on average this year), I would need to fill the N2 tank 3-4 times a year at $130 per fill, and rental is $10 a month, that puts me at $510 - $640 a year for nitrogen, with the dive shop charging $10 for a fill, that is about $250 - $400 per year.  My local gun shop is building a new store with an indoor range with shooting lanes at 25, 50, and 100 yards, indoors!  So my shooting in the winter will be much more than in the past.  I am 70 now, if I stay healthy and shoot another 10 years, that could be between $2500 to $6400 for air/nitrogen.

A $1300 - $2000 compressor is looking better all the time.
Title: Re: Nitrogen.
Post by: Alan on May 22, 2017, 04:50:24 PM
You are a youngster! I've got you by 7 years, and I opted for the Omega Air Charger. It is exactly what you need (I didn't know I needed it until I got it!). And, the next scheduled maintenance for the gearbox is 3,500 hours. Me thinks it will outlast me!

Title: Re: Nitrogen.
Post by: Monkeydad1969 on May 22, 2017, 10:17:57 PM
There's some good info here.  Thanks for all the input.

Joe
Title: Re: Nitrogen.
Post by: Christopher on May 23, 2017, 02:35:50 AM
Thanks Bob for the response, as always.......I appreciate the kudos, but it was dumb luck, as you probably saw. Edited my post to strike out wrong capacities....which was all of it. ::) :-[

Chris

 

 
Title: Re: Nitrogen.
Post by: rsterne on May 23, 2017, 07:36:39 AM
The information I have found is that the CGA-580 fitting used on 3000 psi Nitrogen (and inert gasses like Helium and Argon) is not used on the higher pressure tanks.... The fitting for 6000 psi Nitrogen tanks is shown as a CGA-677 in the list below....

http://www.sisweb.com/referenc/tools/cgafitt.htm

The CGA-580 Nut is 15/16"-14 RH male threads.... while the CGA-677 Nut is 1.03"-14 LH female threads....

Bob
Title: Re: Nitrogen.
Post by: jhm757 on May 25, 2017, 07:32:55 AM
My 6000psi Nitrogen tank costs me $100 a year to lease the tank, and $60 for a refill.

A tank lasts me for a year, and that is a lot of shooting, so total cost is $160 a year.

Only draw back is once it is under 4500psi you don't get a full fill on the 4500psi carbon fiber tank. but still lots of shooting left.

But it sure is nice to always have Nitrogen, and only have to refill once a year. I keep the tank strapped to a beam in the garage.

It is very heavy when it is time to take it in for an exchange. I imagine I could have the exchange delivered, need to look into what they charge for that.

Jim - jhm757

Jim,

That doesn't tell me how long it will last for me.  I need a hard number of refills you can get.  If you refill your 4500 psi tank once a month and I refill once a week, or maybe twice when I am out squirreling, then the nitrogen tank will not last as long for me.  So, with $130 refills here, I need to know how many times a year I would be refilling.  If the cost warrants it, I will get a compressor.

I have a Guppy and never have kept track of how many fills I get, so sorry not much help there.

If this helps I shoot about 2400 pellets a year, based on my order history from PA.

Jim - jhm757