A bead of Sil-floss weighs less than 90 pounds and Fosgene gas takes my breath away
Repaired a small leak today in an RTU using proper service practices: recover, repair, filter/drier, micron vacuum, weigh-in. But all the while I was wondering, could I have repaired this with freon in the system (saving a few hours): 1) the leak was tiny and very accessible, 2) system static pressure was only about 90 psi.
I assume the problems with this procedure would have been: 1) excessive heating of refrigerant, 2) safety, 3) may not work at all, as well as other problems of which I welcome you to remind me.
But just wondering . . . has anyone ever successfully repaired a leak without recovering? Maybe by recovering down to 15 lbs or so?
A bead of Sil-floss weighs less than 90 pounds and Fosgene gas takes my breath away
You stand a better chance (although a VERY slim one) of making a repair in a vacuum depending on what you are using to join your tubing/pipe. Any pressure will push out your filler material and leave you with pinhole leaks. Too much pressure can give you a face full of hot solder/braze material. My nitrogen purge was too high ( 5 PSIG) once and I ended up fixing pinhole leaks after a pressure test revealed the leaks.
Lastly, James Mo is right about the phosgene. You'll get enough in your years of service without trying to make repairs under pressure. Do it safely and do it right.
I cant believe you even posted that thought .What do you think happens to the parent metal when you try to weld .That very small leak will become a very large one in a hurry as the parent metal melts releasing a combination of pressurized burning refrigerant and oil under pressure.I know its hot right now but I think you have spent a little too much time in the sun .Use proper safe environmentally responsible methods to repair leaks,if the customer wants to save money then let them find someone else to fix it.At least you can go home at night in one piece Knowing you did the right thing .!!!!!!!!!!!!!!!!!!!!
I'm speechless on this one.
All my leon freaked out!
Yep, I'm often quite crazy.
Years ago an oldtimer told me he sometimes brought systems down to low pressure before repairing leaks . . . sounded like B.S. and I never gave it that much thought.
But today I was in this experimental mood (surely you've been there) and had this miniscule leak, and late for 2 other calls, and the old guy popped in my head. And since they're quite a few BSing old-timers who frequent this board , . . . off went the question.
Sounds like the answer is an emphatic NO. I appreciate everyone's input.
There is a product used for small leeks. Its about the size of a pen and works like a septic stick. I think you can use a heet gun and rub it on.Never used it ,Dont know the name but have seen it on the shelf.Nxt trip to the suply house ill Check on the name and specs.
Just to add a little more, even though you static is 90, what do you think it will be as you add heat? We all know this is how refrigeration works.
Work smarter not harder.
I saw a repair done on a roto lock under pressure a while back. The "serviceman" took mastic tape and wrapped it around the roto lock fitting and the tubing.
It didnt hold....
The guy who did it has probably 20 years experience in hvac but he works for a hack outfit so he probably is a hack himself.
Its sad isnt it.... some guy spending 20 years doing this work and he comes up on that rotolock and his solution is to wrap tape around it......
Ive seen pvc cement used in vain, all sorts of epoxies...
w
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yeah, I think your Leon must've all freaked out
...sorry,I had to steal it,... just too funny
...SHEEESH!!!
I once had a leak around a schrader stub. It looked as if it had been repaired before in vain. It had this gray hard substance around. Anyway, I pulled the remaining charge and sanded it off.....not easy. Once it was off, just a matter of brazing the leak around the stub.
I asked the more experienced techs at an RSES meeting one night about this strange sealant. I asked them if they have ever seen this stuff on leak repairs. They said it was a two part epoxy marketed some years back. It never caught on.......wonder why.
"Nearly all men can stand adversity, but if you want to test a man's character, give him power."
-Abraham Lincoln
You gotta be freakin kidding me !!!!!!!!!!!!!!!
IF all you need is a TEMPORARY fix on a SMALL leak, Wagner has a product called epox-a-leak. I have used it with success recently on a bubblegum repair for a customer due to changeout an 10 ton condenser. The sytem was flat and the leak was on the pilot line to the reversing valve pilot operator and could not be repaired with a torch and the customer, justifiably so, did not want to approve the correct/expensive replacement of the reversing valve on a unit about to be replaced. The customer was informed as to the temporary nature of the repair and the possibility of it not working at all and gladly approved the work/gamble. (key word being gamble) The epoxy was applied to the leak as directed (properly cleaned and degreased )and while pulling a vacuum to increase odds of penetration. The epoxy was also allowed to cure overnight above 70 Deg ambient. It was checked three weeks later and it was still holding pressure. The circumstances making this repair attempt possible may never surface again, but I was pleasantly surprised by performance of the product, and no, I do not work for Wagner!
Lastly, in keeping with the theme of the topic, the repair was not attempted under pressure.
i have repaired a small leak under a very slight vacuum on a chiller at a hospital. it was a hot day and this was the only cooling they had (very poor planning...only 1 chiller for a hospital?!?!?!?) it was a high side leak. i had them turn the tower water down as low as possible and i cycled the chiller down to about 0.1" hg (by the panel). very quick braze up and they were back in business. if they could not have given me a vacuum it would not have worked. and it still took a fair amount of braze rod under those "perfect" conditions (maybe i filled up the 3/8" line ). still not leaking today.
i would not ever normally try it...but considering it was a hospital...
just recover or better yet, isolate and repair.
good luck.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
I don't care how many calls your backed up, there can never be enough pressure to skip proper & safe service procedures. If there ever was, I'd immediately quit and look for another job. You owe it to your family and yourself.
When you end up blinded or dead, the company your working for will just post a want ad to replace you.
jogas
I agree with Jogas, we should not have to cut corners because of some dumb ass that engineered a building with no redundancy.Next they will expect the economizer gaskets changed on the fly and so on and so on.
oh i understand. this happened to be a small crack in a line. of course, i wouldn't change economizer gaskets on the fly, but my boss tells the story of changing out a leaking valve on the fly on a low pressure chiller while running...he got the new one all doped up and ready...figured that since it was in a vacuum it would suck some air in as he changed it "fast"...he got hosed down with lots of refirgerant and oil (before recovery days)...lesson learned.
"Right" is not the same as "Wise".
Don't step on my favorite part of the Constitution just to point out your favorite part.
Just because you can measure it, doesn't mean it is important. Just because you can't measure it, doesn't mean it isn't important.
the only time i ever got anything to seal under pressure is water lines. I had a water heater with no shut off valve on it blow. I grabbed a ball valve and with it open hooked it up. I think the pro press is the greatest tool.