Introduction to Polyurethane Direct-Buried Insulated Pipes

Polyurethane direct‑buried insulated pipe is a prefabricated, directly buried insulation pipe that offers excellent thermal performance, high safety and reliability, and low installation costs. In addition to advanced technology and superior practicality—qualities that traditional trench‑laying and overhead‑installation methods cannot match—direct‑buried insulated pipes deliver significant social and economic benefits and serve as an effective measure for heat‑supply energy conservation. The use of prefabricated, direct‑buried insulated pipes in district heating systems marks a new milestone in the development of China’s district‑heating pipeline technology.   As global energy resources dwindle and demand continues to rise, energy conservation, emission reduction, and environmental protection have become prevailing trends in worldwide development. Both national and local governments are vigorously promoting the development, application, and industrialization of energy-efficient, low-emission, and environmentally friendly products.
Polyurethane rigid foam insulation materials for the construction industry constitute an important segment of the polyurethane sector, characterized by their versatility and simultaneous provision of thermal insulation, waterproofing, and other functions. These products have, since… 20 Century 60 Since its introduction in the European construction industry, it has already… 40 With a history spanning many years, some countries have even enacted legislation designating polyurethane as the preferred material for thermal insulation and waterproofing in the construction industry. In recent years, driven by the rapid growth of China’s building energy‑efficiency market, rigid polyurethane foam insulation products have been widely adopted in the field of building thermal insulation and waterproofing, becoming one of the leading energy‑saving insulation solutions on the market.
As an integrated building insulation and waterproofing material, rigid polyurethane foam breaks with the traditional single‑functionality of conventional building materials. —— Waterproofing materials are not insulating, and insulating materials are not waterproof; once the waterproofing layer develops a leak, the insulation layer immediately loses its thermal performance. Compared with other single‑function insulation or waterproofing materials, rigid polyurethane foam offers distinct advantages:  
1. Polyurethane rigid foam offers multifunctional performance, combining thermal insulation, waterproofing, soundproofing, and vibration damping in a single material.  
2. It boasts exceptional thermal insulation performance and currently has the lowest thermal conductivity of any building material available in China. (≤0.024) , the insulation material with the highest thermal resistance has a thermal conductivity of only EPS Half of the expanded polystyrene board.

3. The rigid polyurethane foam features a continuous, dense skin and is nearly… 100% Its high‑strength, interconnected closed‑cell structure exhibits excellent impermeability. Applied by spray‑on methods, it creates a continuous, seamless waterproof and thermal insulation layer, forming a jointless roof and an integral exterior wall insulation envelope with outstanding water‑tightness and seepage resistance.

4. Superior self-adhesive performance ( No intermediate bonding material is required. ), It exhibits strong adhesion to roofing and exterior walls, with excellent resistance to wind uplift and negative wind pressure; applied as a continuous spray coating, it completely eliminates… “ Hot joint ” and “ Thermal bridge ”; Flexible gradient technology effectively prevents cracking of the waterproofing layer; mechanized operations, automated batching, consistent quality, rapid construction, and a shortened project timeline.  
5. It exhibits stable chemical properties and a long service life, posing no environmental pollution. It self‑extinguishes in the presence of open flames and, when burned, chars without dripping; the char layer retains its dimensions and shape, effectively blocking air ingress and inhibiting flame spread, thereby delivering excellent fire‑safety performance.  
As the only integrated thermal insulation and waterproofing building material available today, polyurethane rigid foam insulation is still in its early stages of adoption within China’s construction industry. Fortunately, to accelerate innovation in building insulation materials and promote the widespread application of polyurethane rigid foam in energy‑saving building projects, the Ministry of Construction has established a dedicated committee. “ Polyurethane Building Energy-Saving Application Working Group ”, To promote the application of rigid polyurethane foam insulation and waterproofing materials in China’s building energy‑saving sector.  
Polyurethane insulation pipes have a low bulk density. , High strength , Adiabatic , Soundproofing , Flame retardant , Cold-resistant , Anti-corrosion , Non-absorbent , Excellent features such as simple and rapid construction , Has become a building , Transportation , Petroleum , Chemical industry , Electricity , Thermal insulation for industrial sectors such as refrigeration , Waterproofing and Leak Sealing , Essential materials such as seals. (For steel pipe purchases, come to Chengyuan.) 1, Low thermal conductivity:  
Polyurethane foam has the lowest thermal conductivity among insulation materials. , Therefore, it can minimize heat loss from the material.