Section
16 Testing
16.1 Hydraulic tests before installation on board
16.1.1 All
Class I and II pipes and their associated fittings are to be tested
by hydraulic pressure to the Surveyor’s satisfaction. Further,
all steam, feed, compressed air and fuel oil pipes, together with
their fittings, are to be similarly tested where the design pressure
is greater than 7,0 bar. The test is to be carried out after completion
of manufacture and before installation on board and, where applicable,
before insulating and coating.
16.1.4 For
steel pipes and integral fittings for use in systems where the design
temperature exceeds 300°C, the test pressure is to be as follows:
-
For carbon and
carbon-manganese steel pipes, the test pressure is to be twice the
design pressure, as defined in Vol 2, Pt 7, Ch 1, 3.3 Design pressure.
-
For alloy steel
pipes, the test pressure is to be determined by the following formula,
but need not exceed 2p:
16.1.6 Consideration
will be given to the reduction of the test pressure to not less than
1,5p, where it is necessary to avoid excessive stress
in way of bends, branches, etc.
16.1.7 Valves
and fittings non-integral with the piping system, intended for Classes
I and II, are to be tested in accordance with recognised standards,
but to not less than 1,5 times the design pressure. Where design features
are such that modifications to the test requirements are necessary,
alternative proposals for hydraulic tests are to be submitted for
special consideration.
16.1.9 In
no case is the membrane stress to exceed 90 per cent of the yield
stress at the testing temperature.
16.2 Testing after assembly on board
16.2.1 Heating
coils in tanks, gas fuel and fuel oil piping are to be tested by hydraulic
pressure, after installation on board, to 1,5 times the design pressure
but in no case to less than 4 bar.
16.2.3 The
hydraulic test required by Vol 2, Pt 7, Ch 1, 16.2 Testing after assembly on board 16.2.2 may
be omitted provided non-destructive tests by ultrasonic or radiographic
methods are carried out on the entire circumference of all butt welds
with satisfactory results. Where ultrasonic tests have been carried
out, the manufacturer is to provide the Surveyor with a signed statement
confirming that ultrasonic examination has been carried out by an
approved operator and that there were no indications of defects which
could be expected to have prejudicial effect on the service performance
of the piping.
16.2.4 Where
bilge pipes are accepted in way of double bottom tanks or deep tanks,
the pipes after fitting are to be tested by hydraulic pressure to
the same pressure as the tanks through which they pass.
16.2.5 Each
flexible hose assembly and expansion piece intended for use with flammable
liquids is to be provided with a certificate of hydrostatic pressure
testing and conformity of production.
16.2.6 Where
flexible hoses, mechanical pipe connections and/or expansion pieces
are used in bilge, dewatering, sea water or flammable liquid piping
systems, the pipe system is to be hydraulically tested to 1,5 times
the design pressure or 7 bar whichever is the greater.
16.2.7 Pumps
essential for the propulsion or safety of the ship are to be tested
by hydraulic pressure to 1,5 times the nominal pressure rating at
ambient temperature.
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