insulated tube data:
thermal conductivity: <0.043 W/m*K (average temperature: 20+-5)
tensile strength: >24.5 N/cm2
water absorption: <0.01 g/100cm2
thickness thermal shrinkage rate: <7% (120+-5)
temperature resistance: -40~120

copper tube data:
copper: >99.9%
phosphorus:  0.015~0.040%
O tensile strength: >205 N/mm2
1/2H,H tensile strength:  >205 N/mm2