getting ready to charge with r290

[gkiing]

I'm getting ready to charge a chiller with r290. I evacuated the refrigerant a few months ago so I could store it, but now I want to refill it; this time with r290. The cap tube is 6' of .026, does that sounda about right? The heatload will be about 175W.

Can I just use propane from a small propane torch? I cut off the torch head and brazed a shrader valve onto it. This would connect to a small (1l or so I think) cylinder of propane, but im not sure what grade it is.

I'm going to have the system pressure tested by a friend whos and hvac tech before I charge it. Is there anythig else I should know, such as the dangers of propane?

[HawainPanda]

yeah, its flamable! :P

hehe, i dunno, im sure u can do that, nyways goodluck!

[gkiing]

Maybe this will help. Do you think that this will work?

[HawainPanda]

seems good, but...i dunno, isn't the nozzle gonna be..steel? gonna be hard to cut

[JSU]

its prolly bronze, which is easy brazing

[pythagoras]

I would say NO. What temperature will that bottle get to when you start brazing on the schreider valve? What pressure will the propane be in the cylinder at that temperature? And what pressure is that valve(and the bottle itself) rated to.

If I didnt know the answers to those questions, which I dont:) , then I definately wouldnt attempt this.

Regards

John.

[gkiing]

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LOL! I disconnect the torch head from the cylinder before brazing it on.. obviously! That would just be retarded.. lololol

I already cut the head off with a tube cutter, it was bronze and was easy to cut off, I'll braze it on with bronze or silfoss rods.

[pythagoras]

Now why didnt I think of that:D

[HawainPanda]

man, lol pythagoras, i thought of that after u posted...and i thought gkiing mite of killed himself :P

[gkiing]

nah im not that stupid :P

[kayl]

are there any rubber parts inside the torch head?


it may be cheaper in the long run to make a hose fitting to adapt to a bbq bottle though and you dont loose the torch piece
but depending on the purity of the propane torch, it could also be an advantage of using it.
does anyone know how pure the r290 is in those bottles?

[chilly1]

In an oxy/acetyl torch there are rubber O rings on the changable heads and there is a seal ring on the valves (packing)

The same goes for a propane torch.

There are a number of issues with the gas in those bottles;
1. Mercaptan- gas used as an oderant, will react with the materials in the system and get caught up in the filter usually not enough to plug it.
2. Water- The H2O content in propane varies with the refinery and the process used to purify it.
3. Noncondenables- These are the other gasses present in all gasses we use but are usually in the 1 or 2 parts per billion or less in commercial grade propane it may be as high as 2000 to 5000 parts per million.
4. Ph - The Ph of the propane can vary due to other impurities in the mxture this may be detrimential to teh refrigeration system.

All in all it is a good cheap alternative but it has drawbacks. The use of a filter drier sized for the system.

[gkiing]

Well, if propane doesnt work out I'll evacuate it and use r22, but I want to try propane at least once to see how well it works. I don't care about loosing the torch head, it's years old anyway. I did remove the rubber and valves from it before brazing on the shrader so they wouldnt catch fire and such.

[kayl]

when i did mine i found that it leaked through the adjust knob.
i then brazed it up but that was a big mistake as i had no control of the r290
but your torch head is different to mine

ps gkiing i know everyone mentions that you aviator how it rocks
one question are my ears betraying me or does it even have noise function as well

[gkiing]

No, my avatar doesnt have sound, you must be hearing things :D

I thought that the valve might leak, I was going to take it off and braze if, but i want to try it with it on first. How did that work out for you with just the shrader as a regulator? I mean this cylinder isint under a whole ton of pressure, you think it might be ok? The actual valve in the top of the propane cylinder is a shrader so I thought it might be ok.

[kayl]

mine was leaking liquid r290 thought that valve that was the only reason why i brazed it.
it takes a little while to fill but it does work

the other valve was crap it took for eva to get that pin at the correct height, as i screw it onto the bottle it leaked liquid r290, it also wasnt the correct thread so it leaded there as well

cause i had no valve as i screwed it on it would leak liquid r290 around the screw seal on the cylinder, gloves were a must as i did get a liquid burn.
because of the leak when screwing the bottle on and off i only got a few charges out of it.