pressure test

cutter

I have re-piped the boiler in the mechanical room. All the piping in the rest of the house was left alone.
I had the boiler piped to the header and back to the boiler with inch and a quarter threaded pipe and pressure tested it and did not see any bubbles, I did lose about 1 psi per hour. I used dawn dish soap 50/50 water and soap on every threaded joint. There is a hydraulic separater in the system if that makes any difference. Anybody have any suggestions?

Ironman

What pressure did you use?

hot_rod

Does it go to 0 psi, or drop a few lbs and stop?
Air from a compressor is hot, when it cools it may show a few psi drop.

Any gasket connections? those sometimes need to get wet to seal air tight.

The cap on all air vents tight?

Ironman

Also check your test gauge and it’s threads. I ve had more leaks on them than I’ve had on systems.

cutter

Ironman said:

What pressure did you use?

I used 15 lbs

cutter

hot rod said:

Does it go to 0 psi, or drop a few lbs and stop?
Air from a compressor is hot, when it cools it may show a few psi drop.

Any gasket connections? those sometimes need to get wet to seal air tight.

The cap on all air vents tight?

The pressure dropped all the way to zero. over a 12 hour period.
The gaskets on the hydraulic separator leaked but they were tightened up and no longer appear to be leaking. The vent at the top of that is tight.
Unless those gaskets are a real slow leak.

cutter

Ironman said:

Also check your test gauge and it’s threads. I ve had more leaks on them than I’ve had on systems.

The test gauge is new, threads are doped and Teflon taped.
The schrader valve is close to the gauge.

I am tempted to fill with water and see what happens.

hot_rod

You might remove the green gaskets from the Sep and soak them in water for a few minutes and reinstall, this seems to help them seal better. If you want to try the air test again, 25- 26 psi is fine and will show an air leak better.

If all the piping work you have done is visible, and in the mech room, then water will surely show the leaks.

delta T

Agree with all the above, I would use a proper leak locating solution too. I have used 50/50 soap before and it does work, but I have found very slow leaks much better with real leak locating solution because it will leave thin film that will still show bubbles many hours after application, soap and water will dry out and it does not seem to leave a good film.

I found a very slow leak on the seam of a ball valve one time that didn't show up until the next day, when I came back to discover a golf ball sized clump of bubbles on the ball valve. stayed there for 2 hours the day of application and never saw anything, only saw it when I came back the next morning.

NY_Rob

Any unions? .... check them first.

cutter

delta T said:

Agree with all the above, I would use a proper leak locating solution too. I have used 50/50 soap before and it does work, but I have found very slow leaks much better with real leak locating solution because it will leave thin film that will still show bubbles many hours after application, soap and water will dry out and it does not seem to leave a good film.

I found a very slow leak on the seam of a ball valve one time that didn't show up until the next day, when I came back to discover a golf ball sized clump of bubbles on the ball valve. stayed there for 2 hours the day of application and never saw anything, only saw it when I came back the next morning.

Delta T what is a leak locating solution?

cutter

hot rod said:

You might remove the green gaskets from the Sep and soak them in water for a few minutes and reinstall, this seems to help them seal better. If you want to try the air test again, 25- 26 psi is fine and will show an air leak better.

If all the piping work you have done is visible, and in the mech room, then water will surely show the leaks.

All piping is visible, I will bump up the pressure. As for taking the seperater gaskets out and soaking them, there is also the boiler protection valve and the 4 quick setters. Those gaskets don't seem to like to be taken out too often.

cutter

NY_Rob said:

Any unions? .... check them first.

One union, did not see anything there.

Solid_Fuel_Man

I've had pressure relief valves not hold air, but hold water just fine.

cutter

Solid_Fuel_Man said:

I've had pressure relief valves not hold air, but hold water just fine.

Right now I have no pressure relief plumbed on, that will be the next step.

cutter

hot rod said:

You might remove the green gaskets from the Sep and soak them in water for a few minutes and reinstall, this seems to help them seal better. If you want to try the air test again, 25- 26 psi is fine and will show an air leak better.

If all the piping work you have done is visible, and in the mech room, then water will surely show the leaks.

Hot Rod I bumped up the pressure and now I see bobbles at the header joints at the seperator. The connections on that seperator are very hard to get at. What do you think fill it with water and see if they seal. Or take it apart and soak for awhile. All the smaller green gaskets seem to hold.

hot_rod

Fill it with water, those gaskets usually seal when they get wet, give them a crank if you can get a big slip joint pliers or wrench once they get wet, if you can.

Assuming they are aligned without any sideways stress on the unions?

cutter

Hot Rod I actually took them apart and soaked the gaskets for 10 minutes put it back together and 2 of the leaks stopped the last one was very small and has now stopped since I filled the system with water. Actually all of the leaks at the seperator were very small. My main leak was a reducing bushing that is in a very hard to get at spot. I forgot to tighten it up, it was a little tighter than hand tight. It looks like I am good now. Thanks for your suggestions