CSA ANSI NGV 2:2016 pdf free download – Compressed natural gas vehicle fuel containers
3 Definitions
The following definitions shall apply in this Standard: Accredited registrar — a qualified organization accredited by a national or international body (e.g., the Registrar Accreditation Board in the U.S. [RAB]) as operating a certification system (e.g., in accordance with BS 7512, General Criteria for Certification Bodies Operating Quality Systems Certification-Criteria for Technical and Management Competence) that provides third-party assessment, certification, and registration of suppliers’ quality systems to applicable standards (i.e., the ANSI/ASQC Q9000 Series, Quality System Requirements). The registrar’s scope of accreditation is described by the accrediting body for particular industry sectors (e.g., Standard Industrial Classification [SIC]). The registrar is thereby authorized to issue accredited certificates of registration to suppliers in the recognized industry. Autofrettage — a pressure application procedure, used in manufacturing composite containers with metal liners, which strains the liner past its yield point sufficiently to cause permanent plastic deformation which results in the liner having residual compressive stresses and the fibers having residual tensile stresses at zero internal pressure. Composite — a filament and resin system. Destroyed — physically made permanently unusable. Fold — the place where two material flows meet in such a manner as to create a sharp, visual groove. Full wrapped — the reinforcement by a composite material applied over the entire liner including the domes. Fully qualified design — a container that has passed all testing as specified in Clause 4 for relevant materials and Table 1 – Test requirements for new designs for the particular container type. Hoop wrapped — reinforcement by a composite material applied in a substantially circumferential pattern over the cylindrical portion of the liner so that the filament does not transmit any significant stresses in a direction parallel to the container longitudinal axis. Leak or Leakage — release of contents through a defect or crack. Liner — inner gas tight container or gas container to which the overwrap is applied. Maximum service temperature — the maximum temperature to which the container will be subjected in normal service. Pre-stressing — the process that puts the liner in compression. This can be done either by autofrettage or by winding a composite material under significant controlled tension.
Autofrettage pressure — the pressure to which a container is taken with the intent of yielding the liner or inner surface of the container. The autofrettage operation is considered to be part of the manufacturing operation and is conducted prior to proof testing. Burst pressure — the highest pressure reached in a container during a burst test. Fill pressure — the pressure attained at the actual time of filling. Fill pressure varies according to the gas temperature in the container, which is dependent on the filling parameters and the ambient conditions. The maximum fill pressure will not exceed 125 percent of service pressure. Minimum required burst pressure — the minimum burst pressure that is to be met during a burst test. This is the greater of 2.25 times the service pressure or the pressure needed to demonstrate the required stress ratio. Operating pressure — the varying pressure that is developed in a container during service. Service pressure — the container pressure, as specified by the manufacturer, at a uniform gas temperature of 21 °C (70°F) and full gas content. Settled pressure — the gas pressure when a settled temperature is reached.