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