ISO 19893:2011

Overview

ISO 19893:2011 specifies a standardized test method for the resistance of mounted assemblies to temperature cycling for thermoplastics piping systems used in hot and cold water pressure applications. The method evaluates the behaviour of joints, pipes and fittings (rigid or flexible) when subjected to alternating hot and cold water under pressure while parts of the assembly are held under tensile stress and/or flexural strain.

Keywords: ISO 19893:2011, temperature cycling test, thermoplastics pipes, joints and fittings, hot and cold water piping systems.

Key Topics and Requirements

• Test principle: A pipe-and-fitting assembly is subjected to repeated cycles of hot and cold water while being monitored for leakage and deformation.
• Test assembly configuration: Typical arrangement includes three branches:
  • Branch A - prestressed (anchored) straight section;
  • Branch B - free-to-move straight section;
  • Branch C - bent section to impose flexural strain.
• Preconditioning and prestress: Components are preconditioned per manufacturer recommendations; branch A is prestressed to a tensile stress defined by the reference product standard.
• Equipment: Cold and hot water reservoirs, alternation equipment (to switch inlet temperature within 1 minute), balancing valves, pressure gauges, thermostats, supporting brackets and a tensioning device.
• Control and acceptance criteria:
  • Test parameters (temperatures, cycle durations, pressure, tensile stress, bending radius and total number of cycles) are defined by the reference product standard that invokes ISO 19893.
  • Default settings (unless otherwise specified) for diameters <63 mm: 30-minute cycles (15 min cold / 15 min hot), total 5 000 cycles. For diameters >63 mm: 60-minute cycles, total 2 500 cycles.
  • During the first five cycles, balancing valves and joints are adjusted so the temperature drop between inlet and outlet is <5 °C and leakage is corrected.
• Inspection and reporting: Continuous and post-test inspection for leakage; test report must record test conditions, materials, tensile stress, inlet/outlet temperatures, cycle times and counts, test pressure and any leakage or anomalies.

Applications and Who Uses It

• Manufacturers of thermoplastic pipes, fittings and jointing systems - for type testing and product development.
• Independent test laboratories - to perform reproducible temperature cycling durability tests.
• Specifiers, consultants and engineers - to verify long-term joint performance for hot/cold water installations.
• Regulatory and certification bodies - to assess compliance with performance requirements for potable and heated water distribution systems.
• Quality assurance teams - for batch verification and failure investigation.

Practical value: ISO 19893:2011 helps ensure joint integrity and service life of thermoplastic piping systems exposed to realistic thermal stresses, reducing in-service leaks and failures.

Related information

• ISO 19893 was prepared by ISO/TC 138 (Plastics pipes, fittings and valves). The method is intended to be used together with the applicable reference product standard that specifies exact test parameters and service class conditions.