BS EN 17414-1-2020 District cooling pipes – Factory made flexible pipe systems – Part 2: Bonded system with plastic service pipes; requirements and test methods.
5 Requirements
5.1 General requirements
In addition to the general requirements defined in EN 17414-1, the following product specific requirements apply.
5.2 Service pipes, fittings and their connections
Service pipes, fittings and their connections shall comply with:
— EN 12201-1, EN 12201-2, EN 12201-3, EN 12201-5, for service pipes made of polyethylene (PE);
— EN ISO 15874-1, EN ISO 15874-2, EN ISO 15874-3, EN ISO 15874-5, for service pipes made of polypropylene (PP);
— EN ISO 15875-1, EN ISO 15875-2, EN ISO 15875-3, EN ISO 15875-5, for service pipes made of cross- linked polyethylene (PE-X);
— EN ISO 15876-1, EN ISO 15876-2, EN ISO 15876-3, EN ISO 15876-5, for service pipes made of polybutene (PB-H);
— EN ISO 21003-1, EN ISO 21003-2, EN ISO 21003-3, EN ISO 21003-5, for multilayer M pipes;
— EN ISO 22391-1, EN ISO 22391-2, EN ISO 22391-3, EN ISO 22391-5, for service pipes made of polyethylene of raised temperature resistance (PE-RT);
All requirements of the pipes, fittings and their connections shall be met before leaving the production site.
5.3 Axial shear strength of pipe assemblies
The axial shear strength between the service pipe and the insulation shall be at least 0,09 MPa for plastics pipes and 0,12 MPa for multilayer M pipes. The axial shear strength shall be tested in accordance with 6.2. The test result shall be determined as an average of five measurements.
5.4 Linear water tightness of pipe assemblies
When tested in accordance with 6.3, the amount of water leaking through any of the pipe ends shall not exceed 100 g after 168 h.
5.5 Water vapour permeation of pipe assemblies
The pipe supplier shall give information about the risk of water accumulation in the thermal insulation dependant on the service conditions.
NOTE 1 PB, PE, PE-RT, PE-X, PP-R and PP-RCT pipes are slightly open for diffusion of water from the media to the insulation. The rate of diffusion increases with the temperature. The casing is likewise open for diffusion from the insulation to the soil. The rate of this diffusion depends on the casing temperature and the water vapour partial pressure difference over the casing wall. For pipes installed under the ground water table there will always be a certain build-up of water directly under the casing. Experience shows that this build-up is limited and not detrimental to the function although a certain loss of insulation capacity could be expected.
NOTE 2 Multilayer M pipes which consist of a homogeneously closed and longitudinally welded or seamless metal layer with a layer thickness ≥ 100 μm in the pipe construction are considered to be water vapour tight.BS EN 17414-1 pdf download.