Water
Test:
The DWV
plumbing system is plugged leaving the top vent open. Water is
then introduced to the system, purging any trapped air that may
occur. The test passes if no water column is lost or no pressure
drop is noted on a gauge.
Air
Test:
The DWV
plumbing system is plugged at all openings including traps and
vents, leaving one opening as a point to both introduce and
monitor the test pressure. Air is introduced, pressurizing the
system (normally 5 PSI or less), making sure all are outside the
danger zone. (See safety and usage instructions.) The test passes
if the measurable loss of pressure is within the time and pressure
allowances of the test specifications.
Manometer (or U-Tube):
Also known as a
final test, the manometer test verifies trap tightness in a new
plumbing system. All traps are filled with water and all vents are
then plugged. The manometer tube is first filled with water so
that it “zeroes" out. Then the lower tube of the manometer is
placed through a trap. A second hose is then put through the same
trap and a small amount of pressure is applied. A decrease in
water column measured on the manometer scale indicates that there
is a leak in the system.
Scent
Test:
The DWV
system is plugged at all openings except one. Liquid scent is
applied in that opening, which is then plugged. Leaks are detected
via smell.
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Calculating Head Pressure/Feet of Head
1) Measure the distance of the pipe and multiply it by the slope
of the grade.
2) Measure the distance of the pipe above the
plug. (used when pipe is vertical)
In the
example above, the answer is 600 x .01 = 6 feet of head.
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