2nd SS

[martinjon666]

Building a new SS, the last one did ok but it was kinda strung out and nasty looking, this one will be much more compact. ;)
http://img74.imageshack.us/img74/2125/00004041lo.th.jpg (http://img74.imageshack.us/my.php?image=00004041lo.jpg)

this one will be 12" wide and 17" deep and 10" tall.

http://img74.imageshack.us/img74/8417/00004051ym.th.jpg (http://img74.imageshack.us/my.php?image=00004051ym.jpg)


i do have a question about shielding gas. i would prefer to use propane as i have it and its cheap to get more, everyone on here says to learn the risks first, so i am.

I have all of the parts cut and shaped to where i want them, i know i should let the propane in through the cap line to help regulate the flow and reduce the risk of flashback.

1-do i braze the last joint (where the cap line is letting in propane) last?
------how will that joint be shielded?

2- say i start on any joint, there will be propane coming out of every other joint that hasn't been brazed yet, whats to keep them from igniting and causing more problems?

3-i had my system charged with propane and let it air out for 48 hours, i know propane likes to sit at the lowest point of the system, how long should i let it sit before it is safe to start brazing?

I am sure i will come up with more questions as these get answered :D

Jon

[runmc]

Your cutting corners in the wrong place. I don't care how careful you are and how experienced you are. I don't even care how many hundreds of times you've done it. Your still taking a chance that you could space out and forget a joint or an open shrader that propane is purging out of. Gas will build up and flow around the cooler until it reaches an open flame. It's just to big of a risk. Maybe you won't get killed, maybe you'll get lucky and just burn the skin off your face and hands.
I'm not joking. XtremeSystems PhaseChange forum is not the place to discuss this. I'm sorry.

[wdrzal]

answer to ? 1:You remove the valve gut out of one of the schreder valves and let it out flow their.

If your in a situation where that is not possible ,just let the gas flow and soon as you start to push the last joint togeather ,shut off the gas. you line will be full and no oxidation will occur. you still need to open a acess up to releive pressure or as you heat pressure will build and make pin holes in your braze.

answer to ? 3:propane can lay in a low spot almost indefinatly.

[martinjon666]

@ Runmc , I don't know what i said, just asking a question about shielding gas, if you are referring to not using propane at all as a shielding gas, then ok, you do seam rather adamant about it, i'll just wait and get a non-volatile gas later.

@ wdrzal how can i be sure that i get all of the propane out of the system? i'll pick up some dry nitrogen on monday or tuesday and do it with that instead, should i just blast a bunch of nitrogen through the condesor and compressor to try and get all the propane out, is there a better way to make sure tis gone?

Once again i am sorry if i ask the wrong questions, it seems every time i open my mouth i make somebody mad, but i am sure i am not the first person to wonder about these things, and even the wrong questions need to be answered and understood.

[wdrzal]

purge with the dry nitrogen first , then you can vacuum pump system down.

I just want to point out another danger since you already got r290 in the system. if the correct mix with air @ correct % and is tried to pump down,most vacuum pumps expell the contents on top of pump, since heavier :than air the mix could settle on the vacuum pump motor and ingnite.So very possible.

"Myth Confirmed"

[jinu117]

I suggest going to local welding shop, rent nitrogen tank and use nitrogen regulator (which you can buy rather cheap on e-bay). That way you can probably get nitrogen purging done for less than $100.
Better spend a bill than risking yourself. How much a month do you pay for car insurance? :)

[martinjon666]

Good point, actually the local welding shop and the plumbing shop and the hvac shop are all rather amazed by phase change, the welding shop will let me use one of their tanks for nothing, all i have to do is buy the nitrogen, just need to get my hands on a nitrogen regulator and i'll be ready to go.

As to the car insurance, i pay about $300 (and health insurance is also $300) :D kinda sucks but what can you do?

[jinu117]

Good point, actually the local welding shop and the plumbing shop and the hvac shop are all rather amazed by phase change, the welding shop will let me use one of their tanks for nothing, all i have to do is buy the nitrogen, just need to get my hands on a nitrogen regulator and i'll be ready to go.

As to the car insurance, i pay about $300 (and health insurance is also $300) :D kinda sucks but what can you do?

Lucky guy :) mine is half interested... only discount I get (welding shop) is that I had to bring my kids once and they adored them so they are being very nice to me now... :P Ask for nitrogen regulator pricing from them first. Maybe they will give you discount you can't refuse :)

[wdrzal]

Guys theres quit a few place that sell this stuff,plummbing,heating,a/c,refrigeration,industrial & electrical supply houses to start.
you got to hunt them down ,they are not usually on prime property on the main drag, usually backstreets and the like. look in the yellow pages and try to find some that will discount your stuff.

there are company like grainger who are worldwide ,not always the best price but they can get almost anything

http://www.grainger.com/Grainger/wwg/start.shtml

[runmc]

@ Runmc , I don't know what i said, just asking a question about shielding gas, if you are referring to not using propane at all as a shielding gas, then ok, you do seam rather adamant about it, i'll just wait and get a non-volatile gas later.

I'm sorry :( - I wasn't pointing a finger at you. :buddies: It's the purging of systems with propane that I'm addressing.

[Movieman]

Guys, I never post here. cluless on phase except for the essentials, but worked for the oil companies for years and the one thing I can add to this is that propane is one of the nastiest and most explosive gasses out there. Makes gasoline look tame by comparison. I would not let it into any closed area or any area that was even remotely close to a flame source.
You get one life, just one..be smart and live to grow old and enjoy your grandchildren..

[best [486]]

I braze outside and the propane would blow away, or is it still a :nono: [all the systems i built till now i didn't purge anything]

[Movieman]

years ago a 21 year old friend was welding a "cleaned" gasoline tank..
When that empty,cleaned tank blew up they never even found a piece of him to bury. Left a 21 year old wife and baby that never got to know his father.
And propane is many times more flamable than gasoline.
Ok guys, I'll get out of here before I sound like a broken record.
Good Luck to you all.

[wdrzal]

refrigeration systems MUST be clean room clean inside. not using nitrogen to purge will cause oxidation and jeprodize the system.

The statement about propane was almost correct,while it contains masive amounts of chemical energy :gasoline containes 125,000btu per gallon & propane contains 91,000 btu per gallon. Home heating oil #2 contains 139,000btu per gallon.

The thing about propane being extremly flammable is also correct,it boils violantly at 1 atmosphere and produces massive amounts of flammable vapor in open air.

propane can be used safely in torches that are designed for it.

but all this DIY stuff is going to get someone hurt thats why were trying to puta end to it .

movieman is correct in warnning about "empty" vessels ,the vapor mixed with air is the explosive part,.

[martinjon666]

so if i can vaccum each of the components down to 20hg would that be enough to remove the low-lying r290 from the system? how low do i need to get to in order to be sure that there is no propane left in there, so that i can safely braze?

[lross78550]

no wonder i cant get any reply's to my post about a simple off the shelf prommy mach II. you got guys blowing themselves up, posting in this forum makes for much more exciting reading. Why on gods green earth would anyone fill something up with propane then take a propane torch to that item? but hey wth do i know i cant even get a good contact between the evap. ihs and core. much less build my own.
Lee

[Carlz0r]

3:propane can lay in a low spot almost indefinatly.
Yep. I tested that myself. Pressure tested with propane, then removed it all to the point I had to fully remove the schrader valve assembly to lose pressure. Came back two hours later, took a lighter to the valve, and I had a flame burning for about 5 seconds. Now, that's not a lot of propane, but when you think about how long it had been open, it makes you wonder how much longer it could have stayed there. I figure 48 hours would be within safe though. Oh yes, and a lesson I learned myself, that most people already should know, dont braze straight after "removing" the propane :nono: I made that mistake when debrazing a condensor. It literally blew itself off the pipe. Not by much, but there was quite a large flame. I still dont know why I was stupid enough to do that :slap:

[martinjon666]

Work area

http://img159.imageshack.us/img159/5262/00004087cq.th.jpg (http://img159.imageshack.us/my.php?image=00004087cq.jpg)

New Case :)
http://img159.imageshack.us/img159/1108/00004091tn.th.jpg (http://img159.imageshack.us/my.php?image=00004091tn.jpg)

http://img159.imageshack.us/img159/1267/00004102iy.th.jpg (http://img159.imageshack.us/my.php?image=00004102iy.jpg)

Initial charge, purged with nitrogen while brazing the new cap line, 10ft of .031 and a new filter/dryer. i think the old one was clogged up.

http://img159.imageshack.us/img159/6052/00004118bf.th.jpg (http://img159.imageshack.us/my.php?image=00004118bf.jpg)

Next is to mount it all in the case and insulate A LOT:D

[runmc]

It's coming along very nicely - I like the work bench :slobber: Where do you live?

[martinjon666]

Where do you live?

In a town called Firth in Idaho population here is 406 :D

The last place on earth you'd expect a phase changer.

[martinjon666]

Insulated, no load, coulda hit -60 but i accidentally hit the power switch:cussing:


http://img118.imageshack.us/img118/8766/00004192sa.th.jpg (http://img118.imageshack.us/my.php?image=00004192sa.jpg)

some shots of the case with everything in it, minus insulation :)

http://img137.imageshack.us/img137/2995/00004133nl.th.jpg (http://img137.imageshack.us/my.php?image=00004133nl.jpg)
http://img86.imageshack.us/img86/3104/00004145qa.th.jpg (http://img86.imageshack.us/my.php?image=00004145qa.jpg)

[[XC] MarioMaster]

the unit looks great, you should get a fan shroud or a bigger fan

[martinjon666]

actually i don't think i need one, i've checked the air flow and with the cover on the case with both of the fans pointed the same way it pushes more air than the fan i was using that had a shroud. in a way the case acts as a fan shroud.

:D Thank you, i also think it looks good, its all i can do to keep from rubbing it!

[[XC] MarioMaster]

hmm, i guess i keep forgetting my unit doesn't have a case :rolleyes:

[martinjon666]

i got mine fabbed at a local shop for $36. its 16 gauge sheet metal, and i primed it and painted it chrome. the fan holes and such were a pain cause the metal is so thick but it offers great stability.