souffle Posted August 19, 2012 Report Share Posted August 19, 2012 Hi planted tankers, Im thinking about moving from DIY to pressurised CO2 and just wanting to know roughly what the running costs are in terms of (1) refilling bottles and (2) safety testing of bottles (all Trademe listed bottles mention their safety test date so I'm assuming this has to be done every so often??). On my DIY I aim for 1 bubble per 2 seconds so would be using CO2 at about this rate. Its for a 36 inch tank. I'm thinking I'd try and use a 2-3kg bottle since I don't want anything too big... altho if anyone has any comments on whethe this size is appropriate would be great to hear. So my specific questions are: 1. Roughly whats the refill cost for a bottle like this? 2. How long will it last? (I know the answer to this will be 'it depends' but a ballpark figure would be great) 3. Do I need to get it safety checked, how often, and whats the cost? 4. and while I'm at it - is trademe the best place to pick up a bottle or can I get them elsewhere cheaper? Thanks heaps for the advice guys, appreciate it Jay Quote Link to comment Share on other sites More sharing options...
Ira Posted August 19, 2012 Report Share Posted August 19, 2012 You can also rent bottles, then you don't have to worry about any safety testing. I don't know what options on sizes there are though. My father in law rented a massive 3 foot tall one for $10/month I think. Quote Link to comment Share on other sites More sharing options...
Godly3vil Posted August 19, 2012 Report Share Posted August 19, 2012 BOC gas rent 6.5kg bottles out at $17/month refill costs $41. This should last a tank your size 6-12months @ 1/2bps I would think. The also have a handy pickup and drop off service. You can get a regulator with solenoid for $115 off Trademe. Quote Link to comment Share on other sites More sharing options...
Zev Posted August 19, 2012 Report Share Posted August 19, 2012 I have a 2.5kg bottle that I own, it was an old C02 fire extinguisher, it cost $35 to pressure test a few years ago and about the same to refill it, I only have a 64 litre tank and it lasts me just under a year. I think you have to get it tested every five years. I run a Tunze regulator and needle valve and a diffuser that has a glass coil in it so you can count the bubble rate if you are so inclined. You will also need a non return valve that is preferably stainless steel and some air line that is not C02 permeable or they will get brittle after a while. Apparently a ph drop checker is a good thing to have as it gives you an indication of what the ph is in your tank at a glance. Quote Link to comment Share on other sites More sharing options...
Godly3vil Posted August 19, 2012 Report Share Posted August 19, 2012 I have a 2.5kg bottle that I own, it was an old C02 fire extinguisher, it cost $35 to pressure test a few years ago and about the same to refill it, I only have a 64 litre tank and it lasts me just under a year. I think you have to get it tested every five years. I run a Tunze regulator and needle valve and a diffuser that has a glass coil in it so you can count the bubble rate if you are so inclined. You will also need a non return valve that is preferably stainless steel and some air line that is not C02 permeable or they will get brittle after a while. Apparently a ph drop checker is a good thing to have as it gives you an indication of what the ph is in your tank at a glance. Sorry for hi-jacking your thread Souffle, Hey Zev, where did you get your old fire extinguisher tested? and how did you connect the regulator to it, did you have to buy a fitting or? Just asking as I have a few old co2 fire extinguishers in my garage and wouldn't mind using them. Cheers Quote Link to comment Share on other sites More sharing options...
Zev Posted August 19, 2012 Report Share Posted August 19, 2012 I bought it from a guy in Palmerson North who was using it for his tank, it already had the fitting with the tap on it that the regulator screws into when I got it. I get it tested and refilled with food grade C02 at Fire Security Services in Napier, I cannot get it filled at the likes of BOC or Air Liquide locally unless I rent the bottles from them. Quote Link to comment Share on other sites More sharing options...
Luke* Posted August 20, 2012 Report Share Posted August 20, 2012 yea the safety test is every 5 years. i think it's better to own one and refill, it's not that much; then you can just use it when you want and not be worrying bout monthly charges check out sheepsnana's products he's found here: viewtopic.php?f=3&t=59957 Quote Link to comment Share on other sites More sharing options...
phoenix44 Posted August 20, 2012 Report Share Posted August 20, 2012 I have a 7kg bottle that costs $49 to fill up once every 6-7 odd months. Quote Link to comment Share on other sites More sharing options...
si_sphinx Posted August 21, 2012 Report Share Posted August 21, 2012 it costs me $45 every 3 months to fill my 6.5kg bottle. It is also an old Co2 fire extinguisher. Quote Link to comment Share on other sites More sharing options...
souffle Posted August 21, 2012 Author Report Share Posted August 21, 2012 Thanks for all the replies! Really helpful. I'm intrigued about using a CO2 fire extinguisher for the bottle – what do you need to do to it to make sure the regulator fits into it? Would rather avoid paying ~$300 for a bottle so maybe this is a cheaper alternative... And Godly3vil would you be interested in potentially selling one of your old ones? Quote Link to comment Share on other sites More sharing options...
si_sphinx Posted August 21, 2012 Report Share Posted August 21, 2012 Here is a photo of my bottle if it helps... Quote Link to comment Share on other sites More sharing options...
Godly3vil Posted August 21, 2012 Report Share Posted August 21, 2012 You purchased that from HFF though didn't you si? Also yes souffle I probably would but I seriously don't know if it would be worth it once you take all the other costs into account like getting the bottle tested, replacing the fittings to be able to fit a regulator and shipping etc. I did however see one on TM earlier today, here is the link; http://www.trademe.co.nz/building-renov ... 337419.htm Quote Link to comment Share on other sites More sharing options...
Godly3vil Posted August 21, 2012 Report Share Posted August 21, 2012 Also you should add your location to your profile dude, so people know where you are located and you can get better information from people about places around you that might help you out. Quote Link to comment Share on other sites More sharing options...
souffle Posted August 24, 2012 Author Report Share Posted August 24, 2012 OK, location added... Thanks for that Trademe link - those extinguishers look like a bargain! Having said that, done a bit of research into fitting regulators onto CO2 extinguishers and have come across quite a few warnings about the dangers of this, since extinguishers werent specifically designed to be fitted with a regulator. I'm sure 99% of the time it would be fine, but for my piece of mind I think I'll fork out for a standard CO2 bottle. Quote Link to comment Share on other sites More sharing options...
Godly3vil Posted August 24, 2012 Report Share Posted August 24, 2012 I have researched it aswell and as far as I know the general consensus is aslong as you use the right type of thread tape and tighten it enough you should be fine adding a regulator onto a co2 extinguisher bottle. Quote Link to comment Share on other sites More sharing options...
F15hguy Posted August 24, 2012 Report Share Posted August 24, 2012 and avoid using thread seal tape, it can be dangerous with pressurized systems Quote Link to comment Share on other sites More sharing options...
livingart Posted August 24, 2012 Report Share Posted August 24, 2012 what does it do? Quote Link to comment Share on other sites More sharing options...
F15hguy Posted August 24, 2012 Report Share Posted August 24, 2012 creates a weak point, in a pressurised system the pressure bends the metal slightly in the thread making it sealed, having a thread seal in the gap will risk the thread sliding, rare but it does happen (learned this when studying hydraulic systems, scary when you see high pressure liquid injuries) Quote Link to comment Share on other sites More sharing options...
livingart Posted August 24, 2012 Report Share Posted August 24, 2012 little bit different than i was taught in maintenance Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted August 24, 2012 Report Share Posted August 24, 2012 There is a ptfe tape for plumbing and a different tape for CO2 and I used it when setting my system up. Co2 is low pressure after the regulator. Quote Link to comment Share on other sites More sharing options...
F15hguy Posted August 24, 2012 Report Share Posted August 24, 2012 ok, looked into it, seems I have been taught wrong :oops: , Think my tutor must have meant not to thread seal the whole thread as small pieces can enter the hydraulic system. oh well live and learn Quote Link to comment Share on other sites More sharing options...
livingart Posted August 24, 2012 Report Share Posted August 24, 2012 it depends on how much pressure is in the system and the quality of the tape or sealant used Quote Link to comment Share on other sites More sharing options...
alanmin4304 Posted August 24, 2012 Report Share Posted August 24, 2012 You don't put tape on the connection to the cylinder as it is a different type of connection. Quote Link to comment Share on other sites More sharing options...
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