roducts Description
Main Indexs of Pre-insulated Pipe
Product Name
Product Indexes
Reference Standard
Unit
Standard Requirement
Finished product
Steel pipe without thermal insulation layer
CJ/T114-4.4.1
mm
150-250
Increasing rate of HDPE outer protection pipe
CJ/T114-4.4.2
%
≤ 2
Axis eccentricity
CJ/T114-4.4.3
mm
see clause 4.4.3
Expectation of life
CJ/T114-4.4.4.1
year
120℃ 30 years
Shear strength(170℃,1450h after aging)
CJ/T114-4.4.4.2
MPa
(23±2℃)>0.12 (140±2℃) >0.08
Shock resistance
CJ/T114-4.4.5
3kg/2m
see clause 4.4.5
Resistance value between alarm line
CJ/T114-4.4.6
MΩ
more than 20MΩ
Outer protection pipe
Density
CJ/T114-4.2.3.1
kg/m3
≥940
Elongation at break
CJ/T114-4.2.3.4
%
≥350
Tensile yield stength
CJ/T114-4.2.3.4
MPa
≥19
Longitudinal shrinkage rate
CJ/T114-4.2.3.5
%
≤3
Long term Mechanical properties
CJ/T114-4.2.3.6
80℃ 4.0MPa
>1500h free from damage
The difference of the melt flow rate
CJ/T114-4.2.3.2
g/10min
≤0.5
Carbon Black content
CJ/T114-4.2.3.1
%
2.5±0.5
Polyurethane insulation layer
Density
CJ/T114-4.3.2
kg/m3
≥60
Average pore size
CJ/T114-4.3.1
mm
≤0.5
Percentage of close area
CJ/T114-4.3.1
%
≥88
Compressive strength
CJ/T114-4.3.3
MPa
≥0.3
Water absorption
CJ/T114-4.3.4
%
Immersion in boiling water 90 minutes, bubble water absorption should be not more than 10%
Coefficient of thermal conductivity before aging
CJ/T114-4.3.5
w/(m.k)
≤0.033
Cavity
CJ/T114-4.3.1
≤1/3 the thickness of insulation layer
Working steel pipe
Seamless steel pipe(≤DN150)
GB8163
20#, X42,X52,X60,X70
Up to standards
Spiral steel pipe (≥DN200)
GB/T9711 or SY/T5037
Q235B,Q355B,X42,X52,X60,X70
Up to standar
Comments