Krah Pipes Product Center

Material Specifications

Core Materials：Two main options available, compliant with national standard DIN 16961 EN 13476 HDPE (High-Density Polyethylene)：Features excellent low-temperature resistance (-40℃ to 80℃ operating temperature range), good impact toughness, and strong resistance to general chemicals; carbon black additive is integrated to enhance UV resistance, suitable for outdoor buried or exposed scenarios. PP (Polypropylene, mainly PP-HM high-modulus polypropylene)：Superior acid and alkali resistance, higher temperature tolerance than HDPE (short-term resistance up to 100℃), ideal for industrial sewage, chemical liquid transportation, and other corrosive environments. Auxiliary Materials：Food-grade anti-oxidants and UV stabilizers are added to avoid material aging; no metal components (e.g., steel strips) to prevent electrochemical corrosion.

Dimensional & Specification Parameters

Diameter Range：Inner diameter (DN/ID) from 300mm to 4000mm; customized production up to 4500mm for large-scale water conservancy projects; adjacent specifications differ by 100mm (e.g., DN300, DN400, DN500) to match diverse flow demands. Single Pipe Length：Standard 6m per piece (integrated with socket, main body, and spigot via one-time on-line molding); customized length (3m-12m) available for special construction scenarios (e.g., narrow construction sites). Ring Stiffness Grade：Standard grades include SN2, SN4, SN8, SN16; high-stiffness grade SN32 customizable for heavy-load areas (e.g., under highways, high-rise building foundations). Wall Thickness：Horizontal base layer ≥4mm (ensures basic pressure resistance); reinforced layer thickness adjustable (2mm-8mm) based on ring stiffness requirements; total wall thickness ranges from 6mm to 12mm.

Structural & Performance Indicators

Hydraulic Performance：Smooth inner wall with Manning coefficient ≈0.009 (lower than concrete pipes’ 0.013-0.014 and corrugated steel pipes’ 0.012); under the same diameter, flow rate is 17% higher than concrete pipes and 60% higher than corrugated steel pipes. Compressive & Anti-Deformation Performance：SN8 grade pipes can withstand 8kN/m² external pressure (suitable for general municipal buried scenarios); SN16 grade pipes resist 16kN/m² pressure (for heavy-load areas); spiral winding structure ensures uniform stress distribution, avoiding local deformation. Service Life & Corrosion Resistance：Buried service life ＞100 years (no rust or concrete erosion); passes 10,000-hour acid-alkali immersion test (5% H₂SO₄ and 5% NaOH solutions) with no material cracking or performance degradation. Connection Sealing Performance：Socket-and-spigot electrofusion/rubber ring connection; electrofusion joint strength ≥ parent material strength (leakage rate 0); rubber ring (EPDM material) has excellent aging resistance, ensuring no leakage for 50+ years.