2nd plumbing air pressure test

[TimFisher2]

I'm installing a half-bath (toilet, sink) on my second floor. I'm doing the work myself. Right after the rough-in was finished, the city inspector came in to inspect. At that point, I had to perform an air pressure test on the new lines. It passed.

After I am done with the rest of the project (i.e. with sink and toilet in place and hooked up), the inspector will come back to have me perform a SECOND test. This second test will also be an air pressure test, but will also involve putting a tube down into the trap of the toilet.

Anyhow, can anyone fill me in on the details of this test? I'm not really confident that I know what I'm supposed to do. For instance, if the sink is installed, where do I hook up the pressure gauge (the gauge mechanism is also is where I pump the air into the system)? What is this tube going into the toilet trap business? What is being tested with this test?

Any help would be much appreciated.

Thanks,

Tim F Minneapolis, MN

[marson]

you use a manometer (google "manometer plumbing inspection") a tube connected to a manometer in inserted through the water in the trap of the toilet. you blow on it to obtain a one inch difference in the levels (i think, i'm not a plumber so someone might correct me), and it should hold that difference. you need water in all your traps and your vents must be blocked.

[Steve Barker LT]

Sounds like the gas trap test. This is copied from the 2000 international building codes.

P2503.5.2 Finished plumbing. After the plumbing fixtures

have been set and their traps filled with water, their connections

shall be tested and proved gas tight and/or water tight

as follows:

1. Water tightness. Each fixture shall be filled and then

drained. Traps and fixture connections shall be

proven water tight by visual inspection.

1. Gas tightness. When required by the local administrative

authority, a final test for gas tightness of the DWV

system shall be made by the smoke or peppermint test

as follows:

2.1. Smoke test. Introduce a pungent, thick smoke

into the system. When the smoke appears at

vent terminals, such terminals shall be sealed

and a pressure equivalent to a 1-inch water

column (249 Pa) shall be applied and maintained

for the period of inspection.

2.2. Peppermint test. Introduce 2 ounces (59 mL)

of oil of peppermint into the system. Add 10

quarts (9464 mL) of hotwater and seal all vent

terminals. The odor of peppermint shall not be

detected at any trap or other point in the system.

[Christine.Hurney]

Thanks Marson, and Steve (below) for your help. A challenge for me is that I don't have a manometer, and I really don't want to have to buy one. The deal is, I (not the inspector) have to perform this test with the inspector standing there watching me. I'm not sure I have a firm grasp of enough of the details to do that.

[MLD]

A manometer is nothing more that a *U* shaped tube with liquid in the loop and up the sides (any height should be OK). Why not get some clear tubing, make a loop and put water in it. Fasten the loop to some plywood, make it a foot or two long vertically. For the rest, one leg should be long enough to insert into your toilet and the other leg whatever is needed for you to blow into it without difficulty. Put some lined or marked paper behind the loop and make some sort of scale so that you can measure the height difference between the columns. Throw some food coloring in the water to make it easier on the eyes. Of course, the height difference is a function of the liquid that is used in the manometer. Many manometers use Mercury, because of it's density, to keep the height difference to a manageable level. A column of water 34 Ft. high is = to 14.7 psi. So, using water, a 1 in. height difference is only 0.036 psi. (Another way to get the answer---Pressure= height* fluid density). Good luck MLD

[Goedjn]

I dunno why you need a meter. YOu block the vents and the main drain, mark the water level in the toilet, and blow air into the system until the water in the bowl rises an inch. Then come back in however long it's supposed hold the pressure and see if the water level has gone down.

[Christine.Hurney]

Thanks MLD and Goedjn. You've been helpful.

Another question I have about all this is, where do I pump the air in? For the first test, I pumped air into the sink drain line where it enters the wall. But for the second test, that sink (as well as the toilet) will be installed, so I can't pump air at that spot. I'm guessing I'm going to have to add another test tee?

Or do I actually blow air into the system via the u-shaped tube that I will be sticking into the toilet?

Thanks again for your help.

Tim F.