MATERIALS OF CONSTRUCTION
COLD DRAWN SEAMLESS CAR BON STEEL BOILER, SUPERHEATER AND HEAT
EXCHANGER TUBES FOR
DESIGN METAL TEMPERATURES NOT EXCEEDING 454°C (850°F).
Selection of Tubes for Test
Test Specimens – (i)
Test specimens required for the flattening and expanding/
flaring test specified in regulations 38, 39 and 40 shall be taken
from the ends of finished tubes prior to upsetting swaging,
expanding or any other forming operations or being cut to length.
They shall be smooth on the ends and free from burrs and
If desirable and practicable, tensile test may be carried out on
full section of the tubes up to the capacity of the testing machine.
For large size tubes, the tensile test specimen shall consist
of strip cut longitudinally from the tube and which is not
straightened within the gauge length and further heat treated.
If any test specimen shows flaws or defective machining it may be
discarded and another specimen substituted.
All specimens shall be tested at room temperature.
Number of tests. - The
test specified in regulations 38, 39 and 40 shall be made on minimum
2 tubes for first 100 tubes and 1 per 100 or part thereof for tubes
over 100 numbers.