In batch of unmeasured length pipes, up to 5% of pipes with a length from 1.5 to 4 m are allowed by agreement with customer.
For a thread, pipe inner diameter reduce up to 10% is allowed along the entire length of the thread. The mass of 1 m of pipes is calculated with a steel density 7.85 g/cm. Galvanized pipes are heavier than non-galvanized by 3%.
Note: The maximum deviation to the plus side in the wall thickness is limited by the maximum deviations in the mass of pipes. Pipes of conventional manufacturing accuracy are used for water pipelines, gas pipelines and heating systems.
Pipes of increased manufacturing accuracy are used for parts of water supply and gas supply structures.
Maximum deviations in pipe weight should not exceed +8%. At the request of the customer, the maximum deviations in weight should not exceed: +7.5% - for the batch; +10% - for a separate pipe. The curvature of pipes per 1 m of length should not exceed: 2 mm - with a pipe nominal diameter up to 20 mm; 1.5 mm - with a pipe nominal diameter over 20 mm.
Water and gas pipes parameters (GOST 3262-75)
DN (dimensionless) | OD, mm, A | Lightweight | Common | Reinforced |
|---|
| Thickness, mm, B | Mass of 1 m, kg | Meters per ton | Thickness, mm, B | Mass of 1 m, kg | Meters per ton | Thickness, mm, B | Mass of 1 m, kg | Meters per ton |
|---|
| 15 | 21,3 | 2,5 | 1,16 | 862,7 | 2,8 | 1,28 | 782,8 | 3,2 | 1,43 | 700,1 |
| 20 | 26,8 | 2,5 | 1,5 | 667,5 | 2,8 | 1,66 | 603,4 | 3,2 | 1,86 | 536,9 |
| 25 | 33,5 | 2,8 | 2,12 | 471,7 | 3,2 | 2,39 | 418,2 | 4 | 2,91 | 343,6 |
| 32 | 42,3 | 2,8 | 2,73 | 366,6 | 3,2 | 3,09 | 324,1 | 4 | 3,78 | 264,7 |
| 40 | 48 | 3 | 3,33 | 300,4 | 3,5 | 3,84 | 260,3 | 4 | 4,34 | 230,4 |
| 50 | 60 | 3 | 4,22 | 237,1 | 3,5 | 4,88 | 205,1 | 4,5 | 6,16 | 162,4 |
Longitudinal electric-welded pipes
Longitudinal electric-welded steel pipes (GOST 10704-91)
Most often, electric-welded pipes are used for laying pipelines and manufacturing metal structures.
Longitudinal electric-welded steel pipes are manufactured according to the length:
measured length:
with a diameter up to 70 mm - from 5 to 9 m;
with a diameter from 70 to 219 mm - from 6 to 9 m;
with a diameter from 219 to 426 mm - from 10 to 12 m.
Pipes with a diameter over 426 mm are made only of unmeasured length. Pipes with diameter from 70 to 219 mm can be made with length from 6 to 12 m by argeement with the customer;
multiple length - multiples of at least 250 mm and not exceeding the lower limit established for measuring pipes. The allowance for each cut is set at 5 mm (if no other allowance is specified) and is included in each multiplicity
Notes: When making pipes in accordance with GOST 10706, the theoretical mass increases by 1% due to the reinforcement of the weld
По согласованию с заказчиком трубы изготавливаются с размерами: 41,5x1,5-3,0; 43x1,0:1,5-3,0; 43,5x1,5-3,0; 52x2,5; 69,6x1,8; 111,8x2,3; 146,1x5,3; 6,5; 7,0; 7,7; 8,5; 9,5; 10,7; 152,4x1,9; 2,65:168x2,65; 177,3x1,9; 198x2,8; 203x2,65; 299x4,0; 530x7,5; 720x7,5; 820x8,5; 1020x9,5; 15,5; 1220x13,5; 14,6; 15,2 mm, as well as with intermediate wall thickness and diameters within the table below
Pipes of measured and multiple lengths are manufactured in two length accuracy classes: