Cost of Nitrox

[James The Badger]

Just a thought, I joined my local BSAC club (Sussex), I pay £15 a month, but get 'free' clean air and pay cost on the 02 and H
Good value in my book, plus the warm fuzzy feeling of breathing what I hath made..

[PBrown]

Originally Posted by G man

Oh and a air top

** remember to top nice and slow**

It's not the air top that needs to be slow, its the initial decant of O2.

Originally Posted by Bottle Maker

For about less than £5000.00 you can buy a perfectly good Nitrox blending system for home use that will do any mix up 100%.

Upto 100%?, got any more details?, AFAIK membrane systems only go to 40%. I've heard of people getting higher by re-circulating the 40%, but I don't think that's manufacturer approved.

I fill my own in my garage, but I don't actually know how much it costs me (never been bothered to work it out). I don't think its any cheaper than buying it from a shop, but it is much more convienient.

cheers,
Paul

[MattS]

Originally Posted by PBrown

Upto 100%?, got any more details?, AFAIK membrane systems only go to 40%.

Start googling Lewec Stick. It's a continuous feed blending system. You connect an O2 supply (J) upstream of the compressor. A regulator on the O2 supply feeds a special coil (Le Stick) which blends the low pressure O2 with atmospheric air before it is compressed. The O2 feed into the coil is low pressure so you can use a J down to empty without having to cascade and use boosters. For backgas mixes up to 40% there is no need to clean cylinders or the compressor because they are not exposed to pure O2.

The idea has been around for a while but trying to completely mix low pressure air with low pressure O2 at a molecular level was problematic. Mr Lewec, a French Canadian, claims to have cracked it. The system has since been gaining ground with French and Canadian home-brewers, from what I can tell.

[Arfie]

Originally Posted by ajones

I work in Sheffield which brings SDS into play £14.

Just had a 12L filled up there for £7 with 40%. The price is the same for nitrox whether you go for 22% or 40% so it makes sense for me to have 40% for the shallow diving I do and do a couple fo top ups with air.

Arfie

Edit: what the hell am I doing in Tek Talk? I'll get my coat :P

[DIVE BUDDHA]

Originally Posted by Arfie

Just had a 12L filled up there for £7 with 40%. The price is the same for nitrox whether you go for 22% or 40% so it makes sense for me to have 40% for the shallow diving I do and do a couple fo top ups with air.

Arfie

Edit: what the hell am I doing in Tek Talk? I'll get my coat :P

thats one of the reasons i stopped going and using sds!

[Bottle Maker]

[quote=PBrown;875564]It's not the air top that needs to be slow, its the initial decant of O2.



Upto 100%?, got any more details?, AFAIK membrane systems only go to 40%. I've heard of people getting higher by re-circulating the 40%, but I don't think that's manufacturer approved.
cheers,
Paul[/quote

Personal nitrox blending systems are made by APD

Graham.

[PBrown]

Originally Posted by MattS

Start googling Lewec Stick. It's a continuous feed blending system. You connect an O2 supply (J) upstream of the compressor. A regulator on the O2 supply feeds a special coil (Le Stick) which blends the low pressure O2 with atmospheric air before it is compressed.

Thanks Matt, not had any luck searching for Lewec stick, but it sounds like a nitrox stick (similar to the one I finished building this weekend).

Originally Posted by Bottle Maker

Personal nitrox blending systems are made by APD

Ah, I think understand now. Doesn't help me get the gas into the bottle in the first place though.

cheers,
Paul

[David Tombs]

I use DiveCellar at £10 for twin 12's 32%

[iain/hsm]

Originally Posted by Brian of Aquanauts

The running costs of our compressor is about £6000 per year, including filters, annual service, and electricity.
Cost of Helium & O2 including bottle rental c.£2500
Money taken on fills last year £6,600
bri

Hey Bri

I think your paying too much.

Enclosed a pic of an oxygen compressor I installed yesterday. A Pure oxygen compressor delivering 870 cfm (24,640 L/min) with a 450HP 350Kw motor. Running cost is £19.98 per hour in electricity and less then 6K for the service. But then no gas companys ever makes a loss on there compressors or filling gases.

From your numbers £6,600 in sales and £5 per twins that around 1320 twin sets or 2640 cylinder fills at say 80 cfm per fill were talking 211,000 cfm per year. Using a 4Kw motor running 640 hours per year your electricity is around 0.32p per hour or £300 per year. Service is £550 per annum, and if you use the proper industrial re pack cartriges in your filters you would be using around 5 filter changes per year or £75.00 in chemicals.

So from spending £6,000 per year you reduce this to £925. So please send a cheque for £6,600 and I will throw in an oil free oil less 4Kw 5.5 HP 5.5 cfm Nitrox approved to 50% compressor for free!! Your call. iain

[MattS]

Originally Posted by PBrown

Thanks Matt, not had any luck searching for Lewec stick, but it sounds like a nitrox stick (similar to the one I finished building this weekend).

That's the one.
"The Nitrox Stik" Gas Blending System Overview - EnviroDive