Figure 3-31. - Laying sewer pipe to line and grade.

effecting this test. The most widely used test is the water test, although an air test or odor test may be used.

Water Test

Here are the main steps in making a water test. At the lowest point of the section to be tested, insert a test plug in the open end of the pipe or a test tee, like those shown in figure 3-32, and plug other openings. Fill the pipe to its highest level with water; a IO-foot head is required. Leave the water in the pipe for at least 15 minutes before starting the test. This allows the oakum to soak up some water before you look for leaks. If necessary, refill the pipe to overflow and check each joint for leaks.

Air Test

Before making an air test, fill the system with water and allow it to stand until the oakum expands at the joints. Drain the water from the lines and reinsert the test plug. Close all openings and apply air pressure of at least 5 pounds per square inch (psi). In a satisfactory test, the line should hold 5 pounds psi for 15 minutes. If it does not, cover the joints with a soapy water solution and check for bubbles at the leak.

Odor Test

Before making an odor test, plug all openings in the sewer and the branches. After sealing the openings, pour 2 ounces of oil of peppermint in each line or stack. Then pour approximately 1 gallon of boiling water in the stack and seal it. The odor of peppermint at any point in the installation indicates a leak. The inspector, checking the installation for leaks, should not be near the oil of peppermint at any time before the inspection. Such exposure rapidly dulls his or her sensitivity to the odor of peppermint. The peppermint test is not as conclusive as the water and air tests described above, since no pressure is on the pipe.

NOTE

Repeat tests as necessary until all the leaks are located and repaired.

Where a system of pipelines has been installed using gaskets, test one floor at a time. Should there be more than one floor to be tested, be sure all bends, changes of direction, and ends of runs are restrained (limited).