3.9.2.1
Pneumatic Test
Pneumatically test each piping system to 172 kPa (gage) 25 psig, examine
joints with soap solution. Gradually increase to 345 kPa (gage) 50 psig
and hold for 1 hour. The pneumatic test is more hazardous than a
hydrostatic test, therefore, special safety measures, including the waring
of face masks, shall be taken during testing under pressure. Only
authorized personnel shall be permitted in the area during pneumatic and
hydrostatic testing.
3.9.2.2
Upon completion of pneumatic testing, hydrostatically test each piping
system at 1.5 times maximum system operating pressure but in no case more
than 1896 kPa (gage) 275 psig in accordance with ASME B31.3 and API RP 1110,
with no leakage or reduction in gage pressure for 4 hours. Thoroughly
flush piping before placing in operation. Flush piping, including branch
piping, at a minimum velocity of 2.40 meters 8 feet per second. Correct
defects in work provided by the Contractor and repeat tests until work is
in compliance with contract requirements. Furnish electricity,
instruments, connecting devices, and personnel for the tests. Government
will furnish fuel for for piping testing and flushing provided by the
Contractor. Contractor shall be responsible for losses greater than 10
percent.
3.9.3
Testing of Protective Coatings
Perform tests with an approved silicone rubber electric wire brush or an
approved electric spring coil flaw tester. Tester shall be equipped with
an operating bell, buzzer, or other audible signal which will sound when a
holiday is detected at minimum testing voltage equal to 1000 times the
square root of the average coating thickness in mils. Tester shall be a
type so fixed that field adjustment cannot be made. Calibration by tester
manufacturer shall be required at 6-month intervals or at such time as
crest voltage is questionable. Maintain the battery at ample charge to
produce the crest voltage during tests. Areas where arcing occurs shall be
repaired by using material identical to original coating or coating used
for field joints. Upon completion of installation, retest the exterior
surfaces, including field joints, for holidays. Promptly repair holidays.
3.9.3.1
Exterior Coatings of Underground Piping
The coating system shall be visually inspected for holes, voids, cracks,
and other damage during installation. Damage to the protective coating
incurred during transit and handling shall be repaired before installation.
Before lowering into the trench, each pipe section shall be tested by an
electric holiday detector with impressed current in accordance with NACE
RP0274, using a full-ring, spring-type coil electrode. The holiday
detector shall be equipped with a bell, buzzer, or other type of audible
signal which sounds when a holiday is detected. Holidays in the protective
coating shall be repaired immediately upon detection and retested. The
holiday detector shall be a type that field adjustments cannot be made.
Calibration of the tester shall be performed by an independent testing
manufacturer at 6-month intervals or at such time as the crest voltage is
questionable. Following installation, but prior to filling the system with
fuel, all exterior protective coatings, including field joints, shall be
retested with an electric holiday detector as described above. Holidays in
the protective coating shall be repaired immediately upon detection and
retested. Extreme care shall be taken in lifting the piping to perform the
SECTION 15194N
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