Overview
ISO/TR 18124:2006 is an informative Technical Report from ISO covering a test method for multilayer M (metal) pipes used in plastics piping systems. It specifies a cone-expansion procedure to assess the strength of the weld line in the metal layer and the bonding (adhesion) between layers of multilayer M pipes. The document is intended as a product verification / quality-indication test rather than a prescriptive international product standard, due to large variations in pipe designs and tolerances.
Key topics and technical requirements
- Scope and purpose
- Test method for weld line strength in the metal layer and interlayer bonding of multilayer M pipes (polymer + metal layers).
- Applicable to pipes where polymeric materials make up at least 60% of wall thickness.
- Test principle
- Radial expansion of a pipe test piece by controlled insertion of a cone; visual inspection after cone withdrawal to detect weld damage or delamination.
- Apparatus and cone geometry
- Cone with lead-in angle α = 7.5°.
- Cone diameter selection accounts for manufacturer tolerances; typically d_f ≥ 1.1 × d_i unless otherwise specified.
- Clamping device and press–pull unit to insert/withdraw cone centre-lined.
- Test specimen and conditions
- Test piece free length = 4 × d_e (minimum 50 mm).
- Typical test temperature (unless specified otherwise) = (23 ± 2) °C.
- Default number of test pieces = 3 (additional pieces if slippage occurs).
- Procedure parameters
- Insertion speed = (50 ± 5) mm/min.
- Cone remains inserted for (15 ± 1) minutes before withdrawal.
- Lubrication allowed when needed to avoid friction effects.
- Optional force measurement for insertion and withdrawal (requires force measuring device).
- Reporting
- Test report must document identification, dimensions, conditions, observations (damage, delamination, failure type), cone size, post-test internal diameter, average forces (if measured) and test date.
Applications and users
- Practical applications:
- Manufacturing quality control and production verification for multilayer M pipes.
- Failure analysis and investigation of weld defects or interlayer adhesion issues.
- R&D and product development to evaluate bonding methods, adhesives and layer constructions.
- Typical users:
- Pipe manufacturers, production engineers and QC laboratories.
- Independent test labs and product certification bodies.
- Designers and specifiers assessing multilayer piping performance.
Related standards
- ISO 17454:2006 - adhesion testing of multilayer pipes using a pulling rig.
- ISO 17455:2005 - oxygen permeability of barrier pipes.
- ISO 17456:2005 - long-term strength determination for multilayer pipes.
Keywords: ISO/TR 18124, multilayer M pipes, weld line strength, bonding between layers, cone test, plastics piping systems, metal layer testing, product verification.