Litre/min(Cuft/hour) to psi conversion ?

I picked up an inexpensive regulator from Harbor Freight for my back up CO2 tank but the low pressure gauge reads in Litre/min(Cuft/hour). Is there a conversion to psi for this or do I need to replace the gauge.

It sounds like you have a flow meter, not a regulator.

No there is no conversion.

+1 to bja

bja said:

It sounds like you have a flow meter, not a regulator.

No there is no conversion.

Click to expand...

OK so no conversion from Litre/min(Cuft/hour) to psi. Do you think that replacing the gauge to psi would work?

This is a link to the item

http://www.harborfreight.com/regulator-gauge-94841.html

Link is not working.

liters/ min is flowrate. Psi is pressure.

Two totally differnent animals

yes i had a flow guage on my reg. just threw on a 60 psi guage in its place and it works perfect

Sorry about that, it’s working on my phone but not on the computer. This is the description on the web site. I know this is not much info. but it's all there is
CO2/Argon Regulator Gauge Chicago Electric Welding Systems - item#94841


•Designed for light and medium duty MIG/TIG welding jobs
•Cast brass with steel body gauge and chrome plated regulator
•Durable phenolic PVC knob
Max inlet pressure: 230-BAR/ 3335.8 PSI
Overall dimensions: 6-1/8"L X 5"W X 4-1/4"H
0.960-14RH (CGA580) regulator thread with 0.830-14ADP

that looks like a newer version of the one i use, and ya just replace it with PSI guage and ure golden

If it is a flow gauge it will not function properly as you intend. If you change the gauge To psi and set it for 10 psi, it will come out at 10 psi but never stop flowing. You will probably blow up a keg if it's left attached.

JRems said:

If it is a flow gauge it will not function properly as you intend. If you change the gauge To psi and set it for 10 psi, it will come out at 10 psi but never stop flowing. You will probably blow up a keg if it's left attached.

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this makes no sense.. 10 psi is 10 psi.. once your keg equalizes to 10 psi there is no longer any flow... i can assure you my kegs are not blowing up... its still a regulator and does the saem job as any other.. the guage on it just tell you how much gas is flowing by instead of how many psi are pushing on it

i have three of the same regulators from harbor freight. the gauges are mislabled- the inner ring of numbers on the low pressure gauge is actually PSI. the outter ring is MPA or BAR (forget which). no idea why they printed flow rate on a pressure gauge... thats china for you.

JRems said:

If it is a flow gauge it will not function properly as you intend. If you change the gauge To psi and set it for 10 psi, it will come out at 10 psi but never stop flowing. You will probably blow up a keg if it's left attached.

Click to expand...

gauges have nothing to do with how the regulator operates. its also impossible for a gas to come out at 10psi but also never stop flowing. either the gas would stop flowing, or it wouldnt be 10psi; cant do both. flow rate and pressure are not interchangable and dont work like that.

you wont blow up any kegs by using this regulator.

audger said:

i have three of the same regulators from harbor freight. the gauges are mislabled- the inner ring of numbers on the low pressure gauge is actually PSI. the outter ring is MPA or BAR (forget which). no idea why they printed flow rate on a pressure gauge... thats china for you.

Click to expand...

The gauges are not mis-labeled. These are for mig and tig welders which use flow meters.

they are not themselves flow meters though, and can not measure flow rate...?

i put a digital pressure gague downstream of this one and the inner row of numbers perfectly matched the reading of the digital gauge in PSI, which is why i assumed this gague was just mislabled.

I do appreciate all of the information generated. After all is boiled down, what I am understanding is ;

There is no conversion from liter/hour to psi.

A flow gauge and a regulator may or may not be the same piece of equipment.

The low side scale may or may not be labeled wrong.

One thing that I am confident of is that the kegs will NOT explode, that is why there is a pressure relief valve built into every pressure rated vessel.

I believe that I will throw all caution to the wind and give it a shot. At worst I will lose some CO2. If it works I will have an inexpensive back-up regulator. If not, I will still have flowable CO2 for pressurized transfers, purging and the like.

I just bought this regulator from Harbor Freight. I want to try carbonating soda and we have spare CO2 tanks sitting around so why not.

1. From what I've read elsewhere, it comes fitted for Argon, put on the CO2 fitting.

2. The debate is the low gauge (I don't really care about the high gauge). Since the debate is whether the inner ring is PSI or Flow Rate (I can't see how one gauge can read both if there isn't a formula for conversion).

So here is: When we got our kegerator, it had a single-gauge regulator (used system). The screw in front stopped adjusting, so we just bought a shiny new one the next time we were at the local beer distributor (I wanted the HF one but BF didn't trust it). So, since the gauge on the dead regulator is probably still good (yes, it's in the misc. parts box), do you think I can swap it out on this one and be good to go?

3. Or should I take it to my beer distributor and see if they can calculate if the inner ring is PSI contrary to popular belief.

Thank you!

I actually put the harbor freight regulator in service after swapping out the low side gauge with a 0 to 60 psi. I am pleased to say that there have been no issues. We have carbonated 4 kegs and emptied 2 since it has been in use.

the gauge is mislabeled. A gauge cannot measure flow- it has a spring in it which reacts to pressure, not volume- a flow meter is entirely different. Psi is pressure, flow rate is dependent on the psi you are dispensing at, atmospheric pressure, hose size, tank volume- all those things. If you want to know cfm, liters per minute- any rate of volume per time- you need a flow meter. Or you can do what i did, as suggested to me to me aj delange. https://www.homebrewtalk.com/f128/flow-rate-o2-293744/ Take a two liter bottle of water and fill it with two liters of water and hold it upside down in a bucket of water so the water stays in. stick your hose up into the water and turn your gas on and time how long it takes for the gas to displace the 2 l of water in the bottle. This will give you a rough idea of your flow- but it is not exact, since the next time you measure you will have less gas in your tank. you will be in the ballpark, even though the settings on your regulator may not change. That is why there is no conversion, and why that gauge is definitely not measuring volume per time.

I think I'll take it with me next time I get my tank filled (buying an extra tank this weekend). I googled flow meter and pressure gauge and visually the flow meter looks like a rain gauge (well, more like a rain gauge that you put outside than the dial on the regulator). I'll post the results from them here so that it will be able to be looked up when someone has this question again (to verify the earlier test someone posted - two independent tests).

And if they verify, I'm buying another from HF. In the winter we have a heavy beer and a lighter beer that like two different pressures. Right now, we're setting the pressure in between with a little favor to the higher pressure. BF wanted to do multi regulators anyway.

Hey boys just wanted to post the info. I weld a bunch and use l/min regulators all the time. The little ones that come on a small mig are great for home brew. Yes you can just replace the gauge with a psi gauge. And here are some measurements. I just hooked a psi gauge to my regulated line and got

11 liters per min. = 10psi
14 liters per min. = 20psi
18.5 liters per min. = 30psi

Just useful info

manforrilla said:

And here are some measurements. I just hooked a psi gauge to my regulated line and got

11 liters per min. = 10psi
14 liters per min. = 20psi
18.5 liters per min. = 30psi

Just useful info

Click to expand...

There is no correlation between flow rate and psi.

This is true that measuring flow is different than measuring psi. But in a closed system like adding pressure to a closed container like a keg it will reach a certain point and and stop flowing at what ever the regulator is set to. If it was open ended it will flow at the rate that the regulator is set to. There may not be a mathematical formula to determine a relation of one to the other but a fine point sharpie marker will give the marks for the relations listed above.

My local brewery carbonates with a flow meter instead of a psi gauge into their carbonation tank. I have never understood how that works but it does. I believe it will flow at a faster rate and once it becomes carbed up the tank will slowly stop absorbing the carbonation at the setting they have on the gauge. Different.

onthekeg said:

My local brewery carbonates with a flow meter instead of a psi gauge into their carbonation tank. I have never understood how that works but it does. I believe it will flow at a faster rate and once it becomes carbed up the tank will slowly stop absorbing the carbonation at the setting they have on the gauge. Different.

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That's because they use an inline carbonation stone, and the beer instantly gets carbed as it flows through the apparatus with the stone in it. The flow rate determines the volumes of CO2 injected into the beer that passes through it.

bja said:

There is no correlation between flow rate and psi.

Click to expand...

On these small welding system gas regulators there is. The gauge is labeled in Liters per Min. but its just a PSI gauge with a different face. This type of regulator CANNOT read flow BUT knowing the inner diameter of the gas out port you can calculate PSI against that diameter and know ruffly what the flow rate would be. This is the cheap way to give the customer are flow rate regulator. So its not actually a flow rate regulator But thats why these regulators work killer for brewing and you can just replace the gauge with a PSI or like mentioned above bust out a sharpie and hook the gas out to a PSI gauge and mark your 5, 10, 20, 30, psi lines. The readings I gave where off a lincon 110 mig regulator.
eric

Did this regulator work for you?, I just bought one and was going to put a psi in place of the litre/min. but wanted to see If you were sucessful at carbing the keg or if you shot your keg accross the State! LOL

I ended up taking mine back. I couldn't switch out the argon adaptor for the CO2 and neither could the dudes at Harbor Freight. Ended up getting a regulator from Craigs list (bought a tank and it came with 2 regulators - a single gauge and a dual gauge). The dual gauge had a weird fitting (breathable air, go figure) and got that changed at Airgas.

bja said:

There is no correlation between flow rate and psi.

Click to expand...

There is, or it can be calculated, if you know (basically) the pressure differential across a known size orifice. That said, for the point of this to achieve a given total pressure there is little significance to do it.

In the case of something like MIG welding, pressure drop of the stinger assembly would be known based on the design measurements thus if you had "X" PSI of gas applied to the inlet of the stinger it would correlate to a flow rate of the shielding gas.