EN253 SCH40 Underground Polyurethane Foam Prefabricated Insulation Tubes excel in underground thermal insulation. Compliant with EN253 standards, they feature a SCH40 steel core for robust structural strength, withstanding underground pressure and corrosion.
The prefabricated polyurethane foam insulation ensures minimal heat loss, boosting energy efficiency for heating/cooling pipelines. A protective outer layer resists soil chemicals and moisture, extending service life.
Easy to install with precise dimensions, they fit seamlessly in underground systems. Ideal for district heating, water supply, and industrial underground networks, balancing durability, insulation performance, and compliance for reliable long-term use.
EN253 SCH40 Underground Polyurethane Foam Prefabricated Insulation Tube is a professional underground thermal insulation pipe system designed in full compliance with EN253 (the European standard for preinsulated pipes for district heating networks), with the inner steel pipe conforming to SCH40 (a common pipe schedule indicating wall thickness and pressure-bearing capacity). It is primarily used for underground transmission of hot water (≤120°C) in district heating, industrial heating, and urban central heating networks. Its core product features are as follows:
1. Compliance with EN253 Standard & Reliable Quality
Strict Adherence to European Norms: Fully meets the requirements of EN253, which specifies key performance indicators for preinsulated underground pipes—including thermal insulation efficiency, pressure resistance, corrosion resistance, and long-term service life. This ensures compatibility with European and international district heating projects and eliminates quality risks from non-standard products.
SCH40 Steel Pipe for Enhanced Pressure Bearing: The inner carrier pipe adopts SCH40 carbon steel pipe (e.g., S235JR, S355JR), featuring a thicker wall (wall thickness varies by pipe diameter; e.g., DN50 SCH40 pipe has a wall thickness of 3.68mm) and high mechanical strength. It can safely withstand working pressures up to 1.6-2.5 MPa, suitable for medium-to-high pressure underground hot water transmission.
Standardized Manufacturing & Testing: Produced via automated in-situ foaming and layer-bonding processes. Each batch undergoes strict factory testing (e.g., thermal conductivity test, pressure tightness test, bond strength test) to ensure consistent quality across all units.
2. Superior Underground-Adapted Thermal Insulation
High-Efficiency Polyurethane (PU) Foam Insulation Layer: The middle insulation layer is made of closed-cell PU foam with a thermal conductivity ≤ 0.024 W/(m·K) and closed-cell rate ≥ 92%. This dense structure effectively blocks heat transfer, reducing the heat loss rate of underground hot water transmission to ≤ 2%—far lower than traditional insulation materials (e.g., mineral wool) and ensuring energy efficiency for long-distance underground pipelines.
Stable Insulation Under Underground Conditions: The PU foam is tightly bonded to the inner SCH40 steel pipe and outer protective layer, forming a seamless insulation system. It resists moisture absorption (water absorption rate ≤ 1% in 24 hours) even in humid underground soil, avoiding insulation failure caused by water penetration—an issue common in non-prefabricated insulation systems.
Temperature Stability for Underground Use: Maintains excellent insulation performance in the typical underground temperature range (-10°C to 120°C), ensuring stable hot water supply without excessive heat loss, even in cold winter soil.
Multi-Layer Anti-Corrosion Protection for Inner Steel Pipe:
The inner SCH40 steel pipe is pre-treated with hot-dip galvanizing or epoxy coating before PU foaming, forming a primary anti-corrosion barrier against internal corrosion from hot water (e.g., oxygen, impurities in the water).
The outer insulation and protective layers isolate the steel pipe from external underground corrosive factors (e.g., soil salts, groundwater, microorganisms), preventing external rusting and electrochemical corrosion—critical for underground pipes with long service cycles.
Durable HDPE Outer Protective Layer: The outermost layer is made of high-density polyethylene (HDPE) with high impact strength (≥ 25 kJ/m²) and wear resistance. It can withstand mechanical damage during underground burial (e.g., soil pressure, gravel impact, construction machinery collision) and resists degradation from soil chemicals. It also has excellent UV resistance for short-term above-ground storage before installation.
Soil Settlement Adaptability: The flexible bond between the HDPE outer layer and PU foam allows slight deformation of the pipe system, adapting to minor underground soil settlement without cracking the insulation or protective layers—reducing the risk of pipe leakage.
