What is ISO 4427-5 - Polyethylene (PE) pipes and fitting assemblies about?  
The ISO 4427 series of standards are a set of system standards that specify the requirements for a piping system and its components when made from PE.
ISO 4427-5 is the fifth part in the multi-series that specifies the characteristics of the fitness for purpose of pipes and/or fittings assemblies made from PE for buried or above-ground applications, intended for the conveyance of water for human consumption, raw water prior to treatment, drainage, and sewerage under pressure, vacuum sewer systems, and water for other purposes.
In conjunction with the other parts of the ISO 4427 series, ISO 4427-5 is applicable to PE pipes, fittings, their joints and to joints with components of PE and other materials, intended to be used under the following conditions:
- A maximum allowable operating pressure (PFA) up to and including 25 bar1)
- An operating temperature of 20 °C as the reference temperature
Note: The intended uses include sea outfalls, laid in water, and pipes suspended below bridges.
Note: ISO 4427-5 is intended to be only used by the product manufacturer to assess the performance of components according to ISO 4427-2 and/or ISO 4427-3 when joined together under normal and extreme conditions. It is not intended for on-site testing of pipe systems.
Note: For other operating temperatures, guidance is given in ISO 4427-1: 2019, Annex A.
Who is ISO 4427-5 - PE pipes and fitting assemblies for? 
ISO 4427-5 on PE pipes and fitting assemblies is relevant to:
- Manufacturers, designers, and suppliers of PE pipes and fitting assemblies
- Construction industry
- Contractors
- Civil engineers
- Specifiers and installers
- Local bodies
Why should you use ISO 4427-5 - PE pipes and fitting assemblies?
PE is a flexible, lightweight and corrosion-resistant piping product. These benefits make it an ideal piping material for a broad variety of applications such as potable water service or distribution lines, natural gas distribution, lawn sprinklers, sewers, waste disposal, and drainage lines.
ISO 4427-5 walks you through the requirements for fitness for purpose of the assemblies. The assemblies are classified as:
- Electrofusion socket joints
- Electrofusion saddle joints
- Butt fusion joints
- Mechanical joints
- Socket fusion joint
ISO 4427-5 also covers characteristics for fitness for purpose of assemblies, their test parameter and values and standard references for test methods.
By selecting PE pipes and/or fitting assemblies that conform to characteristics under ISO 4427-5, you can ensure that product failure is avoided and overall structural integrity of the external water conveyance systems is maintained. If you are a manufacturer or designer of PE pipes and/or fitting assemblies, ISO 4427-5 can be beneficial for you to ensure durability and operational efficiency of your products.
What’s changed since the last update?
BS ISO 4427-5:2019 supersedes BS ISO 4427‑5:2007, which is withdrawn. BS ISO 4427-5:2019 includes some technical changes with respect to BS ISO 4427‑5:2007. These include: 
- Update of the normative references
- Technical consistency with ISO 4437-3
