How far should you open the main valve on a CO2 tank? The directions on the ReefFantic regulator say:
“Slowly open the main CO2 cylinder valve (located on top of the cylinder). You do NOT need to open the main valve all the way. A couple of turns should do the job.â€ÂÂÂÂÂÂÂ
However I was told at the welding shop where I get tanks filled that if I only open it a little bit that it will likely leak and needs to be opened all the way to pressurize things, so gaskets inside will work properly.
As of currently I’m going with what I used to do when I could afford to scuba dive. Open the tank all the way then go a half turn back. I think this is best because the ReefFantic directions say you do not need to open it, but they don’t say it is bad to or that it would cause harm. Hopefully I’m correct in this because I’ve already had one tank empty in less then two weeks and really don’t feel like driving to the welding shop twice a month to refill tanks when everyone else goes every 6 months or less.
I’m not an expert on CO2 systems per say, but i use compressed air every day as well as propane tanks on a deep fryer on wheels basicly for crack filling streets and from what i know its not about how far your valve is open on the main tank but more how much restriction is on the end of the line (assuming you have flow restriction on the end of the line. If your tank valve is the last possible restriction than you have to gauge it your self.
Jon - use the guage on the left as your guide. that is the one that measures the pressure of your tank. the way the regulator works is by restricting the working pressure(as viewed in the right guage) to the reactor regardless of the source pressure(as viewed in the left guage). as long as the pressure on the left guage isnt off the scale you will be fine.
everything the welding shop is referring to(gaskets, rings, etc) are not applicable because you are using the regulator and because of this you should defer to the manufactures recommedations for the regulator in this case reef fanatic. i have the same regulator if you have any more questions.
If you have a regulator, and I don’t doubt you do as CO2 will run up to 800 psi before it becomes a liquid), you won’t have a problem either opening it all the way or a quarter. You will have plenty of flow with a cracked open valve as the flow through a reactor is relativity low. Regardless, the regulator will regulate the flow to the set psi until the tank pressure gets around the pressure of the regulated pressure (i.e. the tank is running out). I would personally open all the way.
I understand what the gauges are telling me and how they are supposed to work. I don’t understand how I ran out of CO2 so quickly before. I know it did not go through the reactor and must have leaked somewhere. I heard no hissing at all and things were pretty well snug. The welding shop also looked at the teflon tape I had around the CO2 tank and told me that was a no no and another possible leak area.
Just wish all this was going on in my basement not someone elses house, lol.
Like was posted earlier, I don’t pretend to be an expert on these types of tanks, but I have a lot of experience with them for welding and in air suspensions on mini-trucks.
There reason why the welding shop may be saying that you need to turn the valve completely open or blaming the possible leak on not completely opening the valve is because the valve may be constructed such that if it is only partially open it could leak through the valve handle on the top. I have never heard of or seen this, but I wouldn’t completely discount it as a possibility. The welding shop may also have shorted you some CO2 and is trying to cover itself by blaming it on something that you did wrong… I am not saying that is what is happening… but who knows… I do know that just opening the valve slightly will not effect the pressure on the connections and o-rings. The only thing that would effect is how quickly the gas comes through the valve.
When I drove a lowered truck with an air ride suspension and I used a scuba tank, I only opened the valve a couple of turns at most. When I am setting up a welder, or switching welding tanks at the farm I work part at part time, I’ve never completely opened either gas tank valve…
As for the telfon tape, if you are using the correct types of connections (normally the connections are tapered, and may or may not have a rubber o-ring on the male side), you will not need the tape for the connections to make a seal. In the case of the types of connections that are used on high pressure tanks, it could actually cause the connection to not seal, and may even cause the female side of the connection to crack because they are designed to fit extremely tight.
If you want to check for leaks, the easiest way to check is to spray a glass cleaner (like windex, or any type of soap and water mixture) on the connections, coat it pretty heavily, if there is a leak it will bubble up pretty quickly. Obviously you don’t want to do this while it is next to your open sump or aquarium. You can also use spit, if it is too close to your tank or sump, but most people aren’t fond of spitting on their fingers… :~S
I’d then wash all connections down with a water-vinegar mix if you use windex or a soap-water mix… just to be safe.
Well. Probably about 12-13 hours into use, the gauges are down to 0. EMPTY AGAIN! verdict_in
There is a small ~2lb spare tank there and I may hook that one up or have Paul hook it up after I do a bit more research into the possible cause. This time I’ll likely check for leaks. Knew how to check for leaks, but figured since the guy at the welding shop told me three things I was for sure doing wrong that if I fixed them I should be fine. Obviously I still messed something up or there is a leak in the tank or regulator. Going to recommend Paul ventilate the basement a bit as well.
ihuntinde Thanks a lot for your thorough response.
I’m going to write to ReefFanatic for clarification, reread what ihunt posted, ask around on the forums some more, and do some googling. This shouldn’t be too complicated and I’ve connected pressurized tanks to regulators MANY times over during my advanced scuba diving course at UD and during my time in the Caribbean with the team from NOAA.
It might depend on if your tank valve is a ball valve or gate or needle valve. the packing around the valve stem could leak over time and drain the tank to the air. gate valves, plug and others might have a back seat seal to seal the stem packing. in that case open full and tight to the back seat. i dont think ball valves can have a back seat.
another consideration is if somethings breaks open past the valve, you will dump the whole tank of CO2 to your room if the valve is wide open. safety concern for being suffocated. if the valve is only open a crack, it would leak slower and give the gas a chance to be blown away with the AC. a dump would make a high concentration for a while.
so, what kind of valve is it, and what does the manufacturer say?
[quote=“Gordonious, post:12, topic:3020”]
There is a needle valve after a solenoid. Would never be super high pressure headed to either of them because of the regulator.
That is for the regulator… I think kaptken may have been asking about the valve on the tank, which is more than likely either a needle or gate valve. I highly doubt it is a ball valve, you’d know immediately cause it should only turn a quarter of a turn from closed to open and vice versa… I believe most of your high pressure gas tanks have needle valves, if I am not mistaken, but i’ve never actually done any research into it.
I think you are right. the tank valve is no doubt a needle or gate. in which case it can have a back seat seal to prevent leakage past the stem packing to the air.
[quote=“kaptken, post:14, topic:3020”]
I think you are right. the tank valve is no doubt a needle or gate. in which case it can have a back seat seal to prevent leakage past the stem packing to the air. [/quote]
Meaning it needs to be open a good bit to keep that back seal seal from leaking? AKA the guy at the welding some was right.
Perhaps I made a mistake by buying a tank at the welding shop because it needs to be open all the way to prevent leaking, but the regulator instructions seem to indicate that it shouldn’t be open all the way.
[quote=“Gordonious, post:15, topic:3020”]
Meaning it needs to be open a good bit to keep that back seal seal from leaking? AKA the guy at the welding some was right. [/quote]
I am still not convinced this is an issue, but it is a possibility… a leak test would tell you if it is…
[quote=“Gordonious, post:15, topic:3020”]
Perhaps I made a mistake by buying a tank at the welding shop because it needs to be open all the way to prevent leaking, but the regulator instructions seem to indicate that it shouldn’t be open all the way. [/quote]
I also don’t think it would have mattered where you bought the tank. Most CO2 tanks have the same style valve used whether its a beverage style, or welding style. But like I said… I am still not convinced that it MUST be opened all of the way, unless the tank is old and the valve is a little worn out.
Hi, I work at auto repair shop and we all have welding certifications, but I never heard that you have to open valve all the way. I double checked with coworkers and same responce. I would follow regulator mfg. recomendations.
I agree with Rosti and just follow the instructions on the regulator. Then i would leak test it. If its leaking through the stem id open it all the way and leak test it again.
The only problem i could foresee with opening it all the way would be the CFM (the volume of CO2) is higher and the regulator would just need to be calibrated more often. But i am not real sure if that would be something you’d have to worry about or not at a real low PSI.