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.
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.
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.
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.
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