Product Name:TORICH GB/T13793 Material 10#15#20# Q195 215A 235A Steel Pipes with a longitudinal Electric Resistance Weld
Standard:GB/T13793
Size Range: OD: 5-711mm WT: 0.5-50mm Length: 4-12mm or according to customers' actual application and production.
Application:Construction Structure,Liquid Transportation
Steel Grade:10# 15# 20# Q195/Q235/Q345/Q390/Q420
Technology:HFRW
Characteristic:
Good concentricity
Good surface quality
Good OD and ID tolerance
High Precision
Stable quality
Smooth Roughness
TORICH QUALITY ASSURANCE
Table 1 Tolerance of Outer Diameter Unit:mm
| Outer Diameter(D) | General Precesion(PD.A)a | Higher Precision(PD.B) | High Precision(PD.C) |
| 5-20 | ±0.30 | ±0.15 | ±0.05 |
| ﹥20-35 | ±0.40 | ±0.20 | ±0.10 |
| >35-50 | ±0.50 | ±0.25 | ±0.15 |
| >50-80 | ±1%D | ±0.35 | ±0.25 |
| >80-114.3 | ±0.60 | ±0.40 | |
| >114.3-168.3 | ±0.70 | ±0.50 | |
| >168.3-219.1 | ±0.80 | ±0.60 | |
| >219.1-711 | ±0.75%D | ±0.5%D | |
| a Not apply for steel pipe for roller of belt conveyor | |||
Table 2 Tolerance of Wall Thickness Unit:mm
| Wall Thickness(t) | General Precesion(PD.A)a | Higher Precision(PD.B) | High Precision(PD.C) | Non-uniform Wall Thicknessb |
| 0.50-0.70 | ±0.10 | ±0.04 | ±0.03 | ≤7.5%t |
| >0.70-1.0 | ±0.05 | ±0.04 | ||
| >1.0-1.5 | ±0.06 | ±0.05 | ||
| >1.5-2.5 | ±10%t | ±0.12 | ±0.06 | |
| >2.5-3.5 | ±0.16 | ±0.10 | ||
| >3.5-4.5 | ±0.22 | ±0.18 | ||
| >4.5-5.5 | ±0.26 | ±0.21 | ||
| >5.5 | ±7.5%t | ±5.0%t | ||
| a Not apply for steel pipe for roller of belt conveyor b Not apply for General Precesion steel tube. Non-uniform Wall Thickness means the difference between maximum and minimum values of measured wall thickness on the same cross section. | ||||
Table 3 The Bending of Steel tube
| Outer Diameter(D)/mm | Bending/(mm/m),No more than | ||
| General Precesion(PD.A) | Higher Precision(PD.B) | High Precision(PD.C) | |
| >16 | 1.5 | 1.0 | 0.5 |
Table 4 The Height of Inner Burr Unit:mm
| General Precesion | Higher Precision | High Precision |
| +0.50 -0.20 | +0.50 -0.05 | +0.20 -0.05 |
Table 5 Weight coefficient of galvanized steel pipe
| Wall thickness t/mm | 1.2 | .14 | 1.5 | 1.6 | 1.8 | 2.0 | 2.2 | 2.5 | 2.8 | 3.0 | 3.2 | 3.5 | |
| Coefficient c | A | 1.106 | 1.091 | 1.085 | 1.080 | 1.071 | 1.064 | 1.058 | 1.051 | 1.045 | 1.042 | 1.040 | 1.036 |
| Coefficient c | B | 1.085 | 1.073 | 1.068 | 1.064 | 1.057 | 1.051 | 1.046 | 1.041 | 1.036 | 1.034 | 1.032 | 1.029 |
| Coefficient c | C | 1.064 | 1.055 | 1.051 | 1.048 | 1.042 | 1.038 | 1.035 | 1.031 | 1.027 | 1.025 | 1.022 | 1.020 |
| Wall thickness t/mm | 3.8 | 4.0 | 4.2 | 4.5 | 4.8 | 5.0 | 5.4 | 5.6 | 6.0 | 6.5 | 7.0 | 8.0 | |
| Coefficient c | A | 1.034 | 1.032 | 1.030 | 1.028 | 1.027 | 1.025 | 1.024 | 1.023 | 1.021 | 1.020 | 1.018 | 1.016 |
| Coefficient c | B | 1.027 | 1.025 | 1.024 | 1.023 | 1.021 | 1.020 | 1.019 | 1.018 | 1.017 | 1.016 | 1.015 | 1.013 |
| Coefficient c | C | 1.020 | 1.019 | 1.018 | 1.017 | 1.016 | 1.015 | 1.014 | 1.014 | 1.013 | 1.012 | 1.011 | 1.010 |
| Wall thickness t/mm | 9.0 | 10.0 | 11.0 | 12.0 | 12.7 | 13.0 | 14.2 | 16.0 | 17.5 | 20.0 | |||
| Coefficient c | A | 1.014 | 1.013 | 1.012 | 1.011 | 1.010 | 1.010 | 1.009 | 1.008 | 1.007 | 1.006 | ||
| Coefficient c | B | 1.011 | 1.010 | 1.009 | 1.008 | 1.008 | 1.008 | 1.007 | 1.006 | 1.006 | 1.005 | ||
| Coefficient c | C | 1.008 | 1.008 | 1.007 | 1.006 | 1.006 | 1.006 | 1.005 | 1.005 | 1.004 | 1.004 | ||
Table 6 Mechnical Properties
| Steel Grade | Lower yield strength Re1./MPa | Tensile strength Rm/MPa | Elongation A/% | |
| D≤168.3mm
| D>168.3mm | |||
| ≥ | ||||
| 08,10 | 195 | 315 | 22 | |
| 15 | 215 | 355 | 20 | |
| 20 | 235 | 390 | 19 | |
| Q195b | 195 | 315 | 15 | 20 |
| Q215A,Q215B | 215 | 335 | ||
| Q235A,Q235B,Q235C | 235 | 370 | ||
| Q275A,Q275B,Q275C | 275 | 410 | 13 | 18 |
| Q345A,Q345B,Q345C | 345 | 470 | ||
| Q390A,Q390B,Q390C | 390 | 490 | 19 | |
| Q420A,Q420B,Q420C | 420 | 520 | 19 | |
| Q460C,Q460D | 460 | 550 | 17 | |
Table 7 Weight of hot dip galvanized layer
| Weight grade of galvanized layer | Requirement | The total weight of zinc coating per unit area of the inner and outer surfaces /(g/㎡) no less than |
| A | Inside and outside surface | 500 |
| B | Inside and outside surface | 400 |
| C | Inside and outside surface | 300 |
Table 8 Test items and sampling for steel tubes
| Number | Test items | Test frequency | Sampling quantity |
| 1 | Smelting analysis | 1/furnace | 1 |
| 2 | Finished product analysis | 1/furnace | 1 |
| 3 | Tensile test | 1/batch | 1 |
| 4 | Weld tensile test | 1/batch | 1 |
| 5 | Impact test | 1/batch | 2 groups in a time, 3 samples in a group |
| 6 | Flattening test | 1/batch | 1 sample on 2 pipes in each batch |
| 7 | Bending test | 1/batch | 1 sample on 2 pipes in each batch |
| 8 | Flaring test | 1/batch | 1 sample on 2 pipes in each batch |
| 9 | Hydraulic test | All | All |
| 10 | Ultrasonic testing | All | All |
| 11 | Eddy current testing | All | All |
| 12 | Galvanized layer uniformity test | 1/batch | 1/batch |
| 13 | Galvanized weight determination | 1/batch | 1/batch |
| 14 | Galvanized layer adhesion test | 1/batch | 1/batch |
