Wow!

[James Ascherl]

So Im sweating on one of my Taco isolation flanges. The valve was open and the 4' piece of copper was open at the other end. As I looked into the opening of the flange to see what my solder joint looked like on the inside, I grabbed the handle of the valve to see if it was operational. I gave it a slight turn and promptly got blasted in the face by hot steam. It seems that pressure built up between the ball and the housing from the sweating. I was shocked by how much came out. No damage done, but certainly can add it to the ever growing list of lessons learned on this project.

Also, can I leak test my system by pumping air into the system (assuming I isolate my air eliminator and expansion tank)? I would assume air would show leaks better than if I filled it with water. It would also be easier to go back and fix leaks without having to drain the system.

Thanks for any input and Happy New Year.

 

[Hunderliggur]

Air pressure test is the standard, and is required in our county for all plumbing installs. Yes, remove the air eliminator first. Makes it much easier to fix any leaks rather than draining the system.

My rule is NEVER to look into the barrel of anything unless I know it is not loaded!

 

[bpirger]

I learned that turning those handles when everything is very hot can also wreck your valve. The general rule is to sweat with the ball at 45 degrees or so...and if you move to early, as I learned, you can wreck the seals....it was a nice propal combo valve as well!

Some of the air eliminators allow you to "scew" a cover over the vent so that it itself stays in the system, but it just can't vent. Pretty cool. You may also have a pressure relief valve to consider as well....

 

[James Ascherl]

bpirger, Thanks for the tip. I went down to look and I see that my Taco 4900 air seperator can be cranked down to close it.
Hunder, Thanks for your input as well. Shouldn't you have an oomlaut above the u in your name? lol

 

[woodsmaster]

Here is a thread to look at before you fill your system. It is also wow !
https://www.hearth.com/econtent/index.php/forums/viewthread/68151/

 

[4hiswork]

thanks for the reply's here... just about to fire up my system for the first time, great information!

 

[DaveBP]

If you can get at all the fittings that you want to check, I think it is much faster (and therefore more reliable) to pressurize the works to 5 PSI or so and soap test everything. On a boiler size system, especially with storage tanks included, it could take days to see a small leak and the temperature variations would drive you nuts with pressure fluctuations if you were just watching the pressure drop to indicate a leak.

I mix up a very thick solution of liquid dish soap and water, thick enough to see the viscosity. Spray or brush a little on and put a bright flashlight right on it. You can find pin holes with air that might not even leak with water.

 

[woodsmaster]

I'd go up to 60 psi and leave it overnight If the pressure drops any use the soapy water and brush to find the leak. 5 psi
isn't enough.

 

[James Ascherl]

Thanks guys I think I will be filling the system with air to 30psi and let it sit. I am assuming there will be some fluxuation. Either way I will soap all the joints so I should find any leaks. A friend welded the 2" nipples on all three tanks but when I pressure tested them individually, I found a dozen or so pinhole leaks. I dug the slag out with a dremel and a grinder and went over them with a 200w soldering iron. No leaks at 30psi, but that was two years ago-long before this became an obsession and you good folks became family. Oh yeah, my wife wants to know when I am going to get my overpriced "Time Machine" up and running. lol

 

[DaveBP]

If you crank the pressure up high enough you can also test the warrantee on your boiler and expansion tank bladder while you're at it.

 

[huffdawg]

I used 15 psi to test primary tank ,boiler,and all fittings soaped all down then let sit for 24 hrs. alls good except for one small leak on a y strainer.

 

[woodsmaster]

I'd at least go to 30 psi Can't hurt anything with that. Should easily hold 60 with no ill effects. It's nice to Know that If your
system gets to much pressure it's going to come out the relief valve and not somewhere else.

 

[salecker]

Hi
I used air preasure to test my system,i went to 75 PSI,the guy who sold me my boiler and plumbing parts said to go high to weed out the whimps.Had three leaks in my solder joints none on my threaded joints.I even tested the tanks to that preasure,takes a while to pump 1000 gals to 75 PSI.I had hundreds of solder joints and over a hunderd threaded joints.No leaks since i filled with water/glycol.
Thomas