Testing a pipeline shall be carried out before any backfilling
takes place and shall be repeated after backfilling is
completed, and should be in accordance with the standard
specifications of water and air testing of drains and sewers.
Water Testing of a Pipeline
Preparation
Before testing, attention should be paid to the following
points:
Inspect pipeline for possible damage during or
subsequent to laying.
Plugs, should be thoroughly checked. Faulty plugs will
invalidate test results.
Close all opening in the line with watertight seals
(Test Stoppers) ensuring that it's adequately strutted
against movement. i.e. all plugs held firmly in position.
Ventilating valve should be fixed at the high point of
the section.
Testing time should not exceed the test period as
mentioned in the standard (15 minutes).
Testing Procedure
Fill the line with water, commencing at the low point
till you reach a head of 5.0 meter (Testing Pressure)
measured at the low point of the line.
Take care to expel all air from the line.
Inspect the line for any obvious leak.
Maintain test pressure (5.0 m) for one hour by topping
up with water.
Maintain test pressure for another 15 minutes (Test
measuring time).
Measure the amount of water required to maintain this
pressure for 15 minutes, by adding water to maintain the
original level and record the quantity added. This quantity
should not exceed 0.07 l/m2 of wetted inner
surface.
The pipeline is considered acceptable if no leakage is
visible in the pipes, and if water loss in the water head
does not exceed the allowable value (0.07 l/m2).
Air Test
The air test is an alternative to the water test. Pipes can be considered as faulty only in the event of failure under the water test. Test shall be applied as detailed below:
Inspect pipeline for possible damage during or subsequent to laying.
Thoroughly check all plugs and equipment. The average drain plug is quite often not airtight and rubber tubing used in connections must be in good
condition and not perished.
Ensure that the ends of the line are adequately strutted against movement with all plugs held firmly in position.
Pump or blow in air until a pressure of slightly in excess of 4 in. (100mm) water gauge is indicated on the manometer connected to the system.
Pumping or blowing warms the air so a minute or two should be allowed for this to cool to the pipe temperature.
If necessary, then reduce the pressure to 4 in. (100mm) water gauge.
During a further period of 5 minutes the air pressure should not fall below 3 in (75mm) water gauge.
Water Testing of a Pipeline
