(f) Lining
inspection.
The integrity of the
lining on all lined cargo tanks,
when lining is required by this
subchapter, must be verified at
least once each year as follows:
(1) Rubber (elastomeric)
lining must be tested for holes as
follows:
(i)
Equipment must consist of:
(A) A high
frequency spark tester capable of
producing sufficient voltage to
ensure proper calibration;
(B) A probe
with an “L” shaped 2.4 mm (0.09
inch) diameter wire with up to a
30.5 cm (12-inch) bottom leg (end
bent to a 12.7 mm (0.5 inch)
radius), or equally sensitive probe;
and
(C) A steel
calibration coupon 30.5 cm × 30.5 cm
(12 inches × 12 inches) covered with
the same material and thickness as
that to be tested. The material on
the coupon shall have a test hole to
the metal substrate made by
puncturing the material with a 22
gauge hypodermic needle or
comparable piercing tool.
(ii) The
probe must be passed over the
surface of the calibration coupon in
a constant uninterrupted manner
until the hole is found. The hole is
detected by the white or light blue
spark formed. (A sound lining causes
a dark blue or purple spark.) The
voltage must be adjusted to the
lowest setting that will produce a
minimum 12.7 mm (0.5 inch) spark
measured from the top of the lining
to the probe. To assure that the
setting on the probe has not
changed, the spark tester must be
calibrated periodically using the
test calibration coupon, and the
same power source, probe, and cable
length.
(iii) After
calibration, the probe must be
passed over the lining in an
uninterrupted stroke.
(iv) Holes
that are found must be repaired
using equipment and procedures
prescribed by the lining
manufacturer or lining installer.
(2) Linings
made of other than rubber (elastomeric
material) must be tested using
equipment and procedures prescribed
by the lining manufacturer or lining
installer.
(3)
Degraded or defective areas of the
cargo tank liner must be removed and
the cargo tank wall below the defect
must be inspected. Corroded areas of
the tank wall must be thickness
tested in accordance with paragraphs
(i)(2), (i)(3), (i)(5) and (i)(6) of
this section.
(4) The
inspector must record the results of
the lining inspection as specified
in §180.417(b).