ISO 22548-2021 pdf download – Ships and marine technology — Performance test procedures for LNG fuel gas supply systems (FGSS) for ships.
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. If the 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 min. 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 min. 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 min. 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 min. Record the measurement. f) Decrease the flow rate down to 75 % of the test flow rate, maintain the state for 30 min. Record the measurement.