Co2 as a purging gas.

[Chacata]

Hi, nitrogen capable bottles are too big to fit my work vehicle, i rarely need to flush out systems as i mostly install new equipment. Can co2 be used as a purging gas after flushing with diclhoromethane?

[rjsinoz]

have u used co2 before/worked on a co2 freezer.... and you mean carbon dioxide gas right not liquid refrigerant type co2

[Josip]

Hi, Chacata :)


Hi, nitrogen capable bottles are too big to fit my work vehicle, i rarely need to flush out systems as i mostly install new equipment. Can co2 be used as a purging gas after flushing with diclhoromethane?

what kind of plant you need to flush ....

why you use dichloromethane -methylene chloride as a solvent it is a volatile liquid and danger for health in case of inhalation thus forbidden as paint-solvent in EU since 2010.

Flushing with CO2 is also dangerous ...

can you give us more info what you need to do ... to give you the best advice we can;)
Best regards, Josip :)

[NiHaoMike]

CO2 works just fine. Nitrogen is more commonly used because it's cheaper.

Paintball (nitrogen type) or scuba tanks can be used with nitrogen. You'll probably need to remove any moisture left inside before getting it filled.

[Chacata]

Hi, Chacata :)



what kind of plant you need to flush ....

why you use dichloromethane -methylene chloride as a solvent it is a volatile liquid and danger for health in case of inhalation thus forbidden as paint-solvent in EU since 2010.

Flushing with CO2 is also dangerous ...

can you give us more info what you need to do ... to give you the best advice we can;)
Best regards, Josip :)
I mostly do walk ins and commercial ref. The only readily available flushing or cleaning agent here is some kind of dielectric degreaser but it does not say what it is on the label i´m assuming its diclhoro ethane or diclhoromethane.

Rarely i have to flush and purge a system cause whenever possible i install everything new but there are times when i cannot (i.e. pipes buried in masonry ) and i have quite a few bottles of co2 wich are very portable (soda machine kind) and i was thinking of using them to remove the hassle of renting a nitro bottle wich are huge or buying a scuba tank wich are very expensive here. Thanks.

[The Viking]

Wouldn't the whole idea of the purging in this case be to remove moisture?

So your average soda machine C02 gas wouldn't be much use as it isn't a "dry" gas, that's why the Oxygen free Nitrogen is expensive.

Also, if you are thinking of using it for purging whilst you are brazing the whole purpose of that purge is to prevent carbon deposits inside the pipes so to use Carbon diOxide would sort of defeat the object.

:cool:

[NiHaoMike]

It's not to prevent carbon buildup, but oxidation. CO2 works just fine for that.
For a truly inert gas, helium or argon are easy enough to find. They're just really expensive. Helium leaks very easily so it works great for pressure testing.

[passandscore]

Nitrogen is the recommended method. Here is a link for some compact, disposable nitrogen bottles.

http://www.maxxiline.com/product/nitrogengasbottle/nitrogen.html

[The Viking]

OK Mike you got me there,

So how will Carbon diOXIDE prevent oxidation???

:cool:

It's not to prevent carbon buildup, but oxidation. CO2 works just fine for that.
For a truly inert gas, helium or argon are easy enough to find. They're just really expensive. Helium leaks very easily so it works great for pressure testing.

[NiHaoMike]

The oxygen in CO2 is bound very tightly and doesn't release very easily. That's why most fires can be extinguished with CO2. (The main exception is magnesium.)

[Chacata]

Thanks, good info so far. i have used the wrong word, i meant to use the co2 and its pressure and velocity to evacuate the system of any cleaning agent that i always use when reusing old pipes or brazing on old pipes with oil residue that may burn because of the heat. But it would be good to know if i can use it also to purge while brazing.

Thanks to all.

[Josip]

Hi, Chacata :)


Thanks, good info so far. i have used the wrong word, i meant to use the co2 and its pressure and velocity to evacuate the system of any cleaning agent that i always use when reusing old pipes or brazing on old pipes with oil residue that may burn because of the heat. But it would be good to know if i can use it also to purge while brazing.

Thanks to all.

of course in case of brazing the best is to use inert gas .... not sure is it good to use your soda CO2 gas because it is not dry and clean .... in my opinion you can use even pressurized air to remove cleaning agent .. to remove humidity you need to use vacuum pump ...

Best regards, Josip :)