Polyurethane insulation pipe
Polyurethane insulation pipe has smaller foam strength and softer foam. This phenomenon is caused by imbalance of black and white materials. Appropriately increasing the proportion of black material can (1:1-1.05) be careful not to make the proportion of black material too large, otherwise it will make the foam brittle and also affect the performance of the foam.
Polyurethane insulation pipe has become a mature advanced technology in some developed countries. In recent ten years, through digesting and absorbing this advanced technology, the heating engineering technicians in China are promoting the domestic pipe network laying technology to a higher level. More than ten years' practice results fully prove that polyurethane insulation pipe laying mode has many advantages compared with the traditional trench and overhead laying. The directly buried insulation pipe is made up of the conveying medium steel tube, the high density polyethylene outer sleeve pipe, and the rigid polyurethane foam insulation layer between the steel pipe and the outer sleeve pipe. This is also the internal driving force for the rapid development of polyurethane casein heat preservation buried pipe in China's heating engineering.
Polyurethane insulation pipe related standards implementation CJ/T114-2000 "high density polyethylene external protective tube polyurethane foam plastic precast directly buried insulation pipe" standard or EN253 "used for underground heat pipe network of prefabricated insulation system, by the working pipe, polyurethane insulation layer and polyethylene outer tube" insulation pipe. "Seamless steel tube" execution. Gb8163 seamless steel pipe for fluid transportation standard spiral steel pipe shall be in accordance with GB / T 9711.1-1997 technical conditions for delivery of steel pipe for petroleum and natural gas industry standard outer sleeve shall be in accordance with gb13018-91 polyethylene (PE) pipe outer diameter and wall thickness limit deviation standard product technical parameters prefabricated directly buried insulation pipe technical parameters: axial shear strength: ≥ 0.12mpa (23 ± 2 ℃) continuous operation temperature: 140 ℃ Max peak operating temperature: 150 ℃ Max service life: ≥ 30 years (insulation layer and outer protective layer, service life of working steel pipe is related to water quality) pipe end clear area length: 200mm pipe diameter range: dn20-dn1200 working steel pipe executive standard: seamless steel pipe is used for pipe diameter of DN150 and below, executive standard GB / t8163-1999. Spiral welded pipe shall be used for DN200 and above pipe diameter, technical parameters of temperature layer of polyurethane heat preservation pipe shall be in accordance with SY / t5037-2000 or GB / t9711.1: average pore diameter: ≤ 0.5mm, closure rate ≥ 88%, density at any position ≥ 60 kg / m3, compressive strength ≥ 0.3MPa (under 10% deformation), water absorption: ≤ 10% (boiling water at 100 ℃, 90 minutes), technical parameters of low-pressure and high-density polyethylene outer protection pipe: density ≥ 950kg / m3 (20 ℃) Carbon black content: 2.5% ± 0.5% (mass percentage) thermal conductivity: 0.43w / (M. ℃) thermal expansion coefficient: 18010-6 (1 ℃) melt polyurethane insulation pipe index: 0.50 ~ 0.70g (MFI 190 ℃ / 5kg) tensile strength: ≥ 19mpa elongation at break: ≥ 350% environmental stress cracking resistance: ≥ 200H longitudinal shrinkage rate.