Plastiline™ - Humes

11 Testing
11.1 Prior to conducting tests listed in this section, careful
inspection shall be made for visible damage and faulty
welding. After joint welding of blankets in pipelines and
structures, all welds shall be subjected to the tests
specified in this section.
11.2 Particular attention must be given to weld beads on
both sides of weld strips (see illustration). After welding,
beads should be visible on both sides of the weld strip.
The weld must be checked by probing the fillet area with a
well worn (i.e. no sharp edges) screwdriver blade. At any
place where the probe indicates a weak weld, or enters
more than 3mm, a reweld shall be made in
accordance with the procedure specified in Clauses 12.6
and 12.7 of this specification. If overheating has occurred
during welding the evidence is charring at the edge of the
strip. All charred sections must be replaced.
11.3 If required by the client, the lined surface shall be
100% spark tested using an approved spark tester and
brush with a potential of at least 10,000 volts. Two
alternative methods of positively testing joints and
patches are the vacuum box method for flat areas such as
tanks, and the pipe weld tester for pipelines. Both the
vacuum box and pipe weld tester must be of an approved
design. If the vacuum box is used as a means of testing,
Humes should be consulted as special design characteristics
assist in testing by this method.
Defective areas found by these tests must be repaired as
per Section 12 and subsequently retested.
11.4 Where required by the client, a pull test can be
performed to check that proper embedment of keys has
been achieved. A direct pull is applied normal to the
concrete surface, on a cut section of the embedded sheet
containing a single embedded key 100mm to 200mm long.
The concrete should be fully cured and the key shall
withstand the specified pull of 14 N/mm without rupture of
the concrete or the key, or withdrawal of the key from
the concrete. Strictly the test should be made at a
temperature between 10 O C and 27 O C and at least 14 days
after embedment. Refer to Humes if full details are
required.
11.5 Where large areas of lining are involved, testing must
be carried out progressively as the work proceeds to avoid
accumulation of defects from faulty workmanship which
could have been detected and corrected at an early stage.
Spark testing may not detect faults in welds or where
sheets overlap, and must be supplemented by the other
procedures described above in order to ensure sound
workmanship in these areas.
Plastiline spark testing.
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