This part of ISO/TR 12391 applies to seamless steel refillable cylinders of all sizes from 0,5 l up to and including

150 l water capacity produced of steel with tensile strength, Rm, greater than 1 100 MPa.

It can also be applied to cylinders produced from steels used at lower tensile strengths. In particular, it provides

the technical rationale and background to guide future alterations of existing ISO standards or for developing

advanced design standards.

This part of ISO/TR 12391 is a summary and compilation of the test results obtained during the development

of the "flawed-cylinder cycle test". The "flawed-cylinder cycle test" was developed as part of a co-operative

project under the direction of ISO/TC 58/SC 3/WG 14. The "flawed-cylinder cycle test" is a test method to

evaluate the fatigue performance of steel cylinders that are used to transport high pressure, compressed

gases.

The concept and development of the flawed-cylinder cycle test is described in ISO/TR 12391-1. The details of

the test method and the criteria for acceptable fatigue performance of steel cylinders are given in 9.2.6 of

ISO 9809-2:2000, "flawed-cylinder cycle test". In this part of ISO/TR 12391, test results are reported for more

than a hundred flawed-cylinder cycle tests that were conducted on seamless steel cylinders ranging in

measured tensile strength from less than 800 MPa to greater than 1 350 MPa. The test method is intended to

be used for the selection of materials and design parameters in the development of new cylinder designs.