6.3.6.1 For all cargo tanks
and process pressure vessels except integral and membrane tanks, production
weld tests should generally be performed for approximately each 50
m of butt weld joints and should be representative of each welding
position. For secondary barriers, the same type production tests as
required for primary tanks should be performed except that the number
of tests may be reduced subject to agreement with the Administration.
Tests, other than those specified in 6.3.6.2, .3 and .4,
may be required for cargo tanks or secondary barriers at the discretion
of the Administration.
6.3.6.2 The production tests
for types A and B independent tanks and semi-membrane tanks should
include the following tests:
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.1 Bend tests, and where required for procedure tests
one set of three Charpy V-notch tests should be made for each 50 m of weld. The
Charpy V-notch tests should be made with specimens having the notch alternately
located in the centre of the weld and in the heat affected zone (most critical
location based on procedure qualification results). For austenitic stainless
steel, all notches should be in the centre of the weld.
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.2 The test requirements are the same as the
applicable test requirements listed in 6.3.4
except that impact tests that do not meet the prescribed energy requirements may
still be accepted, upon special consideration by the Administration, by passing a
drop weight test. In such cases, two drop weight specimens should be tested for
each set of Charpy specimens that failed and both must show “no break” performance
at the temperature at which the Charpy tests were conducted.
6.3.6.3 In addition to those tests listed in 6.3.6.2.1 for type C independent tanks and process pressure
vessels, transverse weld tensile tests are required. The test requirements are listed in
6.3.4
except that impact tests that do not meet the prescribed energy requirements may still
be accepted upon special consideration by the Administration, by passing a drop weight
test. In such cases, two drop weight specimens should be tested for each set of Charpy
specimens that failed, and both must show “no break” performance at the temperature at
which the Charpy tests were conducted.
6.3.6.4 Production tests
for integral and membrane tanks should be in accordance with Recognized
Standards.