ISO 22548 pdf free download

ISO 22548-2021 pdf free download.Ships and marine technology一 Performance test procedures for LNG fuel gas supply systems (FGSS) for ships.
Other systems such as EDS valve(s), blow down valve(s), etc., should be installed in appropriate locations.
NOTE Bunkering piping is excluded from the scope of the test.
4.2 Test fluid
As a principle, LNG shall be used as the medium to verify the performance of the FGSS.
A medium other than LNG, such as liquefied nitrogen or other fluids colder than the liquefied temperature of LNG, may be used to conduct the test as a reference to the performance of the FGSS, where the system and associated components have been designed for the same colder temperatures if LNG is not practical.
If a fluid other than LNG is used, correction values should be applied as set forth in ISO 6976 (or equivalent standard) based on the actual testing result.
4.3 Test parameters
The test parameters listed in the example report of Annex A. items 3 and 4, shall be measured and recorded during the test that shall be performed according to Clause 5.
The data of pressure, flow rate and temperature of LNG FGSS shall be recorded in accordance with the FGSS clients’ requirements, but in any case, no less frequently than once in every 5 s.
Ambient temperature and humidity shall be recorded before and during the test.
The measuring instruments used in the test shall be appropriately calibrated.
5 Test procedure
5.1 Safety test
5.1.1 Test of e.g. alarm and safety devices
It shall be confirmed that the alarm and safety devices, such as the ESD system, operation of valve(s), etc., are properly operative at ambient temperature and at the minimum working temperature.
The FGSS control system shall be connected and fully operative during the test.
5.1.2 Cryogenic function tests
The cryogenic function tests shall be carried out at the design temperature or lower before pressurizing the FGSS to the design pressure.
The cryogenic function tests shall include following:
a) cryogenic mechanical operation test (e.g. valve operation, leakage verification, etc.);
b) electrical integration test (control system) in cryogenic conditions.
5.1.3 ESD and blow down test
The normal operation of the ESD system shall be confirmed prior to the test set up. The test control system shall be able to shut down the ESD valves in the test setup and safely depressurize the piping system and return it to atmospheric pressure conditions by activating the blow down system. The piping system shall be pressurized with nitrogen prior to this test. This test shall confirm the test arrangement’s capability to shut down (ESD system) and depressurize the FGSS to atmospheric pressure (blow down system) in case of emergency.
5.2 Performance test
The performance test of the FGSS shall be conducted as per the following load steps (refer also to Figure 2). A test report shall be produced based on the data recorded properly (at least once every 5 s) during the test, see example In Annex A.
NOTE If agreed with the client, the testing time at each step can be longer than specified below.
lithe FGSS has more than one supply pipe with different supply pressures, the performance of the FGSS shall be tested for each output separately. (See Figure B.2 in Annex B.)
a) Adjust the discharge pressure of the system to the test pressure. Record the minimum flow rate.
b) Increase the flow rate to 25 %. Upon reaching step 25 % of the test flow rate, maintain the state for 30 mm. Record the measurement.
c) Increase the flow rate up to 50 %. Upon reaching step 50% of the test flow rate, maintain the state for 30 mm. Record the measurement.
d) Increase the flow rate up to 75 %. Upon reaching step 75 % of the test flow rate, maintain the state for 30 mm. Record the measurement.
e) Increase the flow rate up to 100 %. Upon reaching step 100 % of the test flow rate, maintain the state for 30 mm. Record the measurement.
f) Decrease the flow rate down to 75% of the test flow rate, maintain the state for 30 mm. Record the measurement.ISO 22548 pdf download.