When choosing materials for the construction of heating networks, special attention is paid to the thermal insulation characteristics of pipelines, since they determine the level of heat loss and the reliability of the system as a whole. In this regard, pipes in PU insulation are increasingly used in design practice.
Pipes with polyurethane foam insulation are steel pipe products with a thermal insulation layer, designed for the installation of reliable and energy-efficient highways, characterized by a long service life and ease of operation. The use of PU insulation allows the use of pipelines for both above-ground and underground laying.
Insulated pipes are in demand:
- during the construction of DHW and HVAC networks;
- for installation of industrial pipeline systems;
- in district heating systems;
- when laying oil and gas main pipelines.
Installation of steel pipes in PU
The main structural element is a tube made of carbon or low—alloy steel of circular cross-section with a diameter of 25-1420 mm and a wall thickness of 2-11 mm. Rolled products are characterized by high strength and resistance to external influences. The geometric and operational parameters of the products comply with GOST 8732-78 (seamless pipes) and GOST 10705-80 (electro-welded pipes).
The thermal insulation is made of polyurethane foam, which is characterized by low thermal conductivity, moisture resistance and long service life. PU foam has good adhesion to steel and the protective shell, which prevents axial shifts. The quality of the material is regulated by GOST 30732-2020.
HDPE (GOST 18599-2001) or galvanized strips (GOST 52246-2016) are used as an external protective shell. It protects the insulating material and the metal pipe from physical influences and the influence of aggressive external conditions.
Additionally, an operational remote control system (ODS) is installed, which allows obtaining defect data with instant information fixation. The UEC system informs about damage to the pipeline or shell, failures of the signal wire, as well as problems with the installation of joints.
Classification of PU pipes
The outer shell determines the conditions of their operation and the method of laying:
- Polyethylene is used for underground laying both in channels and without them. PE has a high resistance to moisture.
- Galvanized steel is suitable for above-ground installation. The casing is made of tightly wound steel tape, characterized by increased resistance to temperature and humidity fluctuations, exposure to ultraviolet radiation, as well as to mechanical stress and damage.
Thickness
