BS EN 489:2009 pdf free download – District heating pipes – Preinsulated bonded pipe systems for directly buried hot water networks一 Joint assembly for steel service pipes, polyurethane thermal insulation and outer casing of polyethylene.
— able to withstand radial forces and bending moments;
— able to withstand effects of temperature and temperature variations.
In case of double sealing each one of the sealing systems and the combination of both systems shall fulfil the requirements of the type test as described in Clause 5.
4.1.2 Installation of the joint
Each individual step in the installation of a joint shall follow the system supplier’s installation instructions in order to ensure that the joint obtained is equivalent to the joint as previously type-tested.
4.1.3 Competence of the welder and fitter
Persons installing joints on preinsulated pipe networks shall possess a valid evidence of qualification stating that they have received training relevant to the system and the type of joint.
Steel service pipe welders shall possess a valid certificate in accordance with EN 287-1.
Polyethylene welders shall possess a valid evidence of qualification which documents their ability to reproduce welding of the quality specified.
Recommended subjects for training are given in Annex C.
4.1.4 Expected thermal life and long term temperature resistance
The requirements for expected life and long term temperature resistance shall be in accordance with 5.4.4 of
EN 253:2009.
4.1.5 Steel service pipe weld
The steel service pipe weld shall:
— be tight when tested in accordance with A.6;
— have mechanical properties equivalent to those of the service pipe.
4.1.6 Polyurethane rigid foam insulation (PUR)
The foaming of a joint on site shall be carried out in a confined space. The insulation shall completely fill the joint.
The requirements for the rigid PUR foam insulation shall be in accordance with 4.2.3.2, 4.2.3.3, 4.2.3.4 and with
EN 253:2009, 4.4.3 for the compressive strength.
4.1.7 Joint casing
The joint casing shall be tight against external water pressure.
Casings for welded joints shall fulfil Clause 4.3.1 of EN 253:2009.
All joints shall be subject to a leak-test. If this is not possible, a type specific procedure of 100 % visual test in combination with a destructive spot test scheme shall be described in the manufacturer’s documentation.
NOTE Leakage testing of joints should be carried out with air or another suitable gas. The test pressure of 20 kPa should be applied at a temperature of  40 °C for a minimum of 2 mm. The leak-tightness should be checked by means of a suitable indicator liquid or a leakage detector. The indicator liquid should be detrimental neither to the casing and joint material, nor to the environment.
Proper handling and installation procedures and type specific test procedures for the verification of leak-tightness of installed joint casings shall be described in the manufacturer’s documentation.
4.2 Type test requirements
4.2.1 Water tightness
No water ingress shall be detected after the water impermeability test in accordance with 5.2.
Both welded and non-welded joints shall be tested.
4.2.2 Soil stress test
Non-welded joints shall pass the soil stress test in accordance with 5.1 before the water impermeability test in accordance with 5.2 is carried out.