ISO 22548 pdf download Ships and marine technology — Performance test procedures for LNG fuel gas supply systems (FGSS) for ships
This document specifies evaluation methods of characteristics such as pressure, flow rate, temperatureand system stability of fuel gas supply systems (FGSS), which are manufactured to use vaporizedliquefied natural gas(LNG) or boil-off gas as fuel gas supply to the vessel’s gas consumers. lt is applicableto evaluate the performance of the LNG FGSs: (1) prior to delivery or after installation on board a ship,and (2) to assure the system characteristics are taken into account for the entire gas consumers duringship’s gas trial or sea trial.
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references, only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.IMO, International Code for the Construction and Equipment of Ships carrying Liquefied Gases in Bulk (IGCCode)
IMO, International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code)
3Terms and definitions
For the purpose of this document, the following terms and definitions apply.
lSO and IEC maintain terminological databases for use in standardization at the following addresses:- ISO Online browsing platform: available at https://www.iso .org/obp
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LNG fuel gas supply systemLNG FGss
system that supplies gas fuel at the temperature, pressure and flow conditions required by the gasconsumer, from the fuel tank(s) to the gas consumer, excluding the fuel tank(s), in-tank pump(s) tankESD valve(s) and the master gas fuel valve(s) used to control the gas supply
maximum operating pressure (MPa) measured during the test period3.3
minimum operating pressure (MPa) measured during the test period3.4
pressure variation (MPa) during the test period, defined as the difference between the maximumpressure (3.2) and the minimum pressure (3.3)
arithmetic mean of the mass flow rate (kg/h) measured during the test period3.6
arithmetic mean of the temperature (C) measured during the test period3.7
temperature ( c) of the fluid during the test, designated by the client3.8
pressure (MPa) of the fluid during the test, designated by the client3.9
test flow rate
flow rate (kg/h) of the fluid during the test, designated by the client3.10
emergency shutdown systemESD system
system that safely and effectively stops the flow of LNG and vapour in LNG operations
The LNG FGSS under test shall be designed in accordance with the lGC and/or IGF Codes established bythe International Maritime Organization (IM0) for the safety of systems.
The test arrangement used for the performance test shall supply a test fluid to the inlet of the systemand related devices at the required test pressure, test temperature and test flow rate designated by theclient, without disruption.
Before any test run is carried out, all relevant arrangements for the safety of attending personnel shallbe available and operational, and their correct functioning shall be ensured.
For safety, the air shall be properly replaced with inert gas or a suitable medium in the test arrangement.The system and the test arrangement shall be maintained at cryogenic temperatures prior to the test.Provisions, to the maximum extent possible, should be made to minimize the methane emission.Figure 1-shows a typical test arrangement.
Typical examples of LNG FGSS within the scope of the test are shown in Annex B.