The axial pipes dilatation is limited by friction force acting between jacket pipe and sand trench. The stress is absorbed by PPR- pipe shape change (thickness and diameter) and in firm PUR foam by transferring the stresses to sand trench. For underground application, there is no need to use any dilatation elements. Before using the piping system, pipes must be backfilled and properly compacted.
|Carrier pipe||copolymer PPR-3, outside diameter 20 - 110mm, standards: DIN 8077, DIN 8078, DIN 4726, DIN 16962, tlakové rady: PN16, PN 20|
|Thermal insulation||PUR - foam: EN 253|
|Casing pipe||HDPE for underground application, diameter 90÷560 mm: EN 253 , SPIRO for underground application|
|pipe construction||uninsulated ends 160 ± 10 mm for butt or electrofussion welding|
The ends of PPR pipes are not insulated in the length of 200±10 mm.
Allowed operation pressures, based on temperature:
Other pressure classes (PN20, PN25) on demand. PPR system can be regularly overheated up to 70°C to destroy mycobacteria from the system.
The minimum durability of thermal pre-insulated PPR pipes during permanent thermal and pressure load is 30 years.
Thermal pre-insulated PPR pipes are supplied with the lengths 6 m (12 m).
Thermal losses – underground application - for media temperature 60 °C
Other dimensions or enforced insulations can be supplied on demand. Production program for PE servis pipe is 50, 63, 75, 90, 110, 125, 140,160,180, 200, 225, 250, 300 mm.
Thermal pre-insulated diameter reduction is standard - L = 2 m – or according to the agreement
Transitions PPR pipes to steel (or other) , eventually valves are provided by flanged welded-on, or plastic-metal welded-on thread joints (up to A75 mm).
End sleeves, end caps, wall sealing, flanged valves etc. can be supplied on demand
Installation of pre-insulated PPR pipes
No dilatations has to be taken into account when burying pipes min.. 0,5m under ground.
The minimum ambient temperature during installation must be +5°C!
You can use standard methods of PPR pipes joining, recommended by suppliers of PPR. Before insulating the joints, do pressure test to ensure, the system is tight.
Transportation and warehousing
Pre-insulated PPR pipes must be transported and stored on a flat surface, or wooden pads of minimum width of 100mm at the distances 2 m.
Minimum storage temperature is +5°C. Components must be protected from rain and direct sunshine ( to be covered, or stored in the warehouse). When unloading from vehicle – don’t throw on the ground, use fabric strap belts when lifting by crane. Store in pyramids (max. 2m high). Chemical components, shrinking sleeves, end cups, sealing, valves should be stored in warehouse to be protected against whether conditions.