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The A106 Seamless SMLS Carbon Steel Pipe
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"Pipe in Pipe" Process Polyurethane Pre-insulated Pipe for Underground

  • Application Range

Product application: Heat supply, cooling supply, anti-corrosive in the field of crude oil transportation, thermal insulation pipeline engineering.

Medium temperature: ≤120℃ (Accidental peak＜140℃)

Medium pressure: ≤2.5MPa

Laying mode: It is mainly used for direct-buried laying, and can also be used for ditch or overhead laying pipeline.

  • Product Advantages

The quality of the products is in accordance with the national standard and the European standard. The thermal conductivity is low, the heat-insulating property is good, the heat loss is small, the energy-saving and environment-friendly. The unique production process has strong water-proof and anti-corrosive capability, can be directly buried in the underground or water, has short construction period and low comprehensive cost. It has good corrosion resistance and impact resistance at low temperature, and can be directly buried in frozen soil layer. The long-term service life can reach more than 30 years at 140 ℃.

  • Product Capacity

4000KM/YEAR

Pre-insulated pipe production and inspection process

Main Indexes of Pre-insulated Pipe

Product IndexesReference StandardStandard RequirementOur product value
Finished product
Steel pipe without thermal insulation layer (mm)CJ/T114-4.4.1150～250220±30
Increasing rate of HDPE outer protection pipe (%)CJ/T114-4.4.2≤21.2
Axis eccentricity (mm)CJ/T114-4.4.3see clause 4.4.3qualified
Expectation of lifeCJ/T114-4.4.4.1120℃30 year qualified
Shear strength (MPa) (170℃,1450h after aging)CJ/T114-4.4.4.2(23±2℃)≥0.12
(140±2℃)≥0.08 		0.181
0.106
Shock resistanceCJ/T114-4.4.5See clause 4.4.5qualified
Resistance value between alarm line(ΜΩ)CJ/T114-4.4.620ΜΩ～∞qualified
Outer protection pipe
Density (kg/m3)CJ/T114-4.2.3.1≥940948.2
Elongation at break %CJ/T114-4.2.3.4≥350618
Tensile yield strength(MPa)CJ/T114-4.2.3.4≥1920.5
Longitudinal shrinkage rate (%)CJ/T114-4.2.3.5≤31.23
Long term Mechanical propertiesCJ/T114-4.2.3.6 >1500h (80℃，4.0 MPa) free from damagePass
The difference of the melt flow rate (g/10min)CJ/T114-4.2.3.2≤0.50.11
Carbon Black Content %CJ/T114-4.2.3.12.5±0.52.4
Polyurethane insulation layer
Density (kg/m3) CJ/T114-4.3.2≥6071.1
Average pore size(mm)CJ/T114-4.3.1≤0.5qualified
Percentage of close area (%)CJ/T114-4.3.1≥8894
Compressive strength(MPa)CJ/T114-4.3.3≥0.30.58
Water absorption (%)CJ/T114-4.3.4Immersion in boiling water 90 minutes , bubble water absorption should be not more than 10%≤5.53
Coefficient of thermal conductivity before aging W/(m•K)CJ/T114-4.3.5≤0.0330.032
CavityCJ/T114-4.3.1≤1/3the thickness of insulation layerqualified
Working steel pipe
Seamless steel pipe(≤DN150)GB816320#qualified
Spiral steel pipe(≥DN200)GB/T9711 or SY/T5037Q235Bqualified

The mark of the pre-insulated pipe
Below information should be marked on the HDPE outer protection pipe: diameter and thickness of the working steel pipe, diameter and thickness of the pre-insulated pipe, product standard code, production date and batch number, the logo or name of the manufacturer.

The transportation of the pre-insulated pipe
Crane should be used in the transportation, insulation pipe segments must be used to prevent the damage of the HDPE outer protection pipe and the insulation layer, in the process of loading, collision throws and rolling on the ground should be avoided.

The storage of the pre-insulated pipe
The ground should be flat, no rock and hard sundries, the area can’t be full of water, ensure that the pipe and the joint seal waterproof, pre- insulated pipe stacking height should not be higher than 2 m, the pipe should not be long time in open air, it is appropriate to use tarpaulin cover to protect the pipe.

Specification of Pre-insulated Pipe

DNSteel pipe(mm)HDPE pipe(mm)Thickness of insulation layer(mm)
diameterthicknessdiameterthickness
25323.0902.526.5
40453.51102.530
50573.51203.028.5
70764.01403.029
80894.01503.027.5
1001084.51803.033
1251334.52253.542.5
1501595.02503.941.6
2002196.03154.943.1
2502736.03655.640.4
3003257.04207.040.5
3503777.05007.853.7
4004267.05608.858.2
4504788.06008.852.2
5005298.06559.853.2
6006308.076011.553.5
7007208.085012.053
80082010.096014.056
90092010.0105514.053.5
1000102010.0115514.053.5
1100112012.0125614.054
1200122012.0137016.059
1200122014.0137016.059
1400142014.0158016.064
1400142016.0160018.072

Remark:

Insulation pipe fittings carry out the national standard GB/T29047-2012 and the ministry of construction standards CJ/T114-2000

According to the customer’s requirement, we can also make other specifications of steel pipe and HDPE outer protection pipe.

The insulation layer can be made according to the customer’s requirement.

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