Overview
ISO 21307:2017 - Plastics pipes and fittings: Butt fusion jointing procedures for polyethylene (PE) piping systems establishes general principles and standardized procedures for butt fusion of PE pipes and fittings. The standard specifies three recognized butt fusion procedures - single low-pressure, dual low-pressure, and single high-pressure - and covers the materials, equipment, process steps and quality assessment needed to produce reliable fusion joints. ISO 21307:2017 is intended to be applied together with relevant national regulations, codes of practice and other ISO piping standards.
Key Topics
- Butt fusion procedures: detailed descriptions of the three procedures (single low-pressure, dual low-pressure, single high-pressure) and when each is typically used.
- Butt fusion process steps: cleaning, clamping, planing/face preparation, alignment, heating (bead-up and heat soak), heater plate removal, fusion jointing and cooling.
- Process parameters and calculations: guidance for calculating gauge pressure, accounting for drag pressure, and defining heater plate temperatures and timing. (Annexes A–C give example parameter values.)
- Terminology and definitions: standardized terms such as bead-up, heat soak, fusion jointing pressure, cooling times and operator qualifications to ensure consistent practice.
- Equipment and safety: references to butt fusion equipment requirements (see normative reference ISO 12176-1).
- Quality control and testing: requirements for destructive and non‑destructive joint integrity testing (including visual examination with requirements) and guidance on documenting weld records.
- Operator competence: roles and responsibilities of the operator and pipeline operator, and the importance of qualified personnel using written procedures (see ISO/TR 19480).
Applications
ISO 21307:2017 is used by organizations and professionals involved in the design, construction, installation and inspection of polyethylene piping systems, including:
- Pipeline and utility contractors and site welders
- Pipeline operators and asset owners
- Fabricators and PE fittings manufacturers
- Quality assurance personnel and third‑party inspectors
- Technical committees and regulatory authorities developing national welding practices
Typical practical uses include developing welding procedures, qualifying butt fusion equipment and operators, preparing installation and inspection protocols, and ensuring consistent, high‑quality fusion joints in PE piping used for transport of fluids (including gaseous fuels) and other utility applications.
Related standards
- ISO 12176-1 - Equipment for fusion jointing polyethylene systems - Butt fusion (normative reference)
- ISO/TR 19480 (operator qualification guidance) and other ISO piping standards that specify PE component dimensions and materials
Keywords: ISO 21307:2017, butt fusion, polyethylene (PE) piping systems, fusion jointing procedures, PE pipes and fittings, weld quality control, gauge pressure, heat soak.