Pressure test?

Brad White_144

Yes, isolate the vents (Spirovent) and tank for the pressure test. This is exactly what I did for the hydronic board and LLH for my Susan's Vitodens installation. Tested it to 100 PSIG air pressure (and with ME's encouragement, I found a weeping leak at a union). She holds. Done.

Then you can test the rest of the system to appropriate pressure of course.

Be sure that if you leave a valve at the expansion tank connection, to remove the handle or tag it "Do Not Close". Nah, remove the handle and hide it. :)

Andy_14

Can this be pressure tested as it sits? I would have no problem capping the secondary pipe ends and adding air to the piping but don't know how the air vents work. Would the air just go out them? Also could it damage the expansion tank? How about relief valves?

[Deleted User]

Suggestions...

THe expansion tank should have its own isolation and drain valve. If you don't isolate it, you could distend the diaphragm and it could mask any small leaks in the system.

You can put a 1/2" threaded cap on the outlet of the SPiro vent for pressure testing purposes. You will only be able to test as high as the pressure relief valve setting (Am assuming 30 PSI relief), but if it holds rigidly at 29 PSI, it will hold just fine.

Nice job...

ME

Andy_14

Thanks, the boiler relief is 30psi and I had planned to test at 25psi if testing was possible. I will cap the spirovent and disconnect the expansion tank.

[Deleted User]

Hide it under the access cover for the boiler....

NO ONE WOULD EVER think of looking there:-)

Works for me...

ME

Cosmo_3

Painters

The remarks about removing handles reminds me of a new construction job a couple of years ago.

The home was not yet complete, however the heat was on to keep the painters happy in the freezing outside weather. Knowing the painters were going to need water, I removed all the hose bib boiler drains, and installed a short piece of hose on the well pump drain.

Would you believe the tile guys were using their pliers and were taking boiler water to mix grout with, because they "needed hot water". Then people wonder why we have short tempers sometimes.....

Nice job up there, as these guys suggest install a stop and waste ball valve for the expansion tank (waste on tank side, or better yet a hose bib), and use a 1/2" coupling with a 1/2" plug (a cap will not fit over the spirovent air vent).



Cosmo

Andy_14

It will be no problem installing a valve and drain between the vent and exp tank. What is the use for them? Is it only for initial system set/start-up and to make replacing tank down the road easier? Or is their other reasons i'm missing?

Brad White_145

Just those reasons (no message)

Brad White_145

Drawing off System Water

Your post, Cosmo, reminded me of a recent true story at Boston's Prudential Tower.

I was over there in process of designing the replacement chiller plant, 4,000 tons of cooling. The Pru Tower is 750 feet tall so water pressures in the basement, closer to 800 feet, run almost 350 PSIG...

One of the things we kept getting into trouble with was the chemical treatment of the cooling tower water, chilled and even hot water. TDS was way up, pH was down, a mess.

Turns out that the gentlemen who run the valet parking service in a choice of languages no less, also had a thriving side business washing and detailing your car while you shop.

Seems these gentlemen found drain valves with amazingly convenient hose-ends on an unlimited multi-temperature water system! What a country!

They learned that the condenser water made a good first rinse -a high pressure rinse at that- where the process started, the chilled water would work in a pinch but the hot water at the finish line gave a nice suds... probably killed any Legionella from Phase One.