Rigid polyurethane‑sprayed polyethylene‑wound prefabricated direct‑buried pre‑insulated pipes are composed of three closely‑integrated parts: steel pipe (working steel pipe), sprayed rigid polyurethane foam (insulation layer), and wound polyethylene (outer jacket). The products are widely used in heating, thermal insulation and cold‑preservation projects.
Product Features:
(1) Polyurethane spraying process. The polyurethane insulation layer delivers better density uniformity, more stable thermal conductivity, higher closed‑cell rate and lower water absorption, as well as smaller axial eccentricity of the insulated pipe.
(2) The polyurethane insulation layer is formed by free foaming. The cell expansion direction is perpendicular to the axial direction of the pipe, which improves the compressive strength of the insulation layer.
(3) Stronger bonding performance between polyurethane insulation layer and working steel pipe. The polyurethane insulation layer is formed by spraying: liquid raw materials are sprayed onto the steel‑pipe surface and then foam up. Thanks to the high reactivity of sprayed polyurethane raw materials, its bonding force outperforms other processes.
(4) Superior bonding performance between polyurethane insulation layer and polyethylene outer jacket. The rough surface of polyurethane foam facilitates adhesion between the insulation layer and the outer jacket.
(5) Thinner polyethylene outer jacket. The polyethylene outer jacket adopts reduced thickness while guaranteeing service performance, so as to save costs.
(6) The polyethylene outer jacket is formed by circumferential winding. Subject to process stretching, its mechanical indicators including circumferential elongation and tensile strength are significantly improved.
Specifications & Models：
Nominal outside diameter: DN300‑1600 mm
Execution Standard：
GB/T 34611‑2017 Rigid Polyurethane Spray‑polyethylene Winding Prefabricated Direct‑buried Insulating Pipes
Certifications:
Five‑system certification, CE certification, China Building‑materials Green Certification
