GB Seamless steel pipe model size?

Answer; GB Seamless steel pipe model size?

Specifications and dimensions; 6 8 10 12 14 16 18 *1-3 20*2 24 25 28 30 32 *3-8 34 36 38 40 42 45 48 *3-12 50 51 54 57 60 *3-15 65 68 70 73 76 80 83 89 *3-25 95 102 108 14 121 127 *4-35 13 140 146 152 159 168 *4-50 178 180 194 203 219 245 *6-60 273 29 325 351 35 37 *6-90 402 406 426 450 457 465 *8-80 480 50 508 510 530 560 *8-80 580 610 630 60 680 720 *10-120。

GB seamless steel pipeLimited pickling passivation capacity: Pickling passivation paste is not all-round, and it is difficult to remove the gray-black oxide scale produced by plasma cutting machine and CNC flame cutting.

6. Serious scratches caused by human error: In the process of lifting, transportation and construction, the scratches caused by human errors such as bumps, bumping, dragging, and hammering are serious, which increases the difficulty coefficient of metal surface treatment, and is also the key reason for rust after solving.

<> national standard seamless steel pipe is made of steel ingots or solid pipe blanks perforated into capillaries, and then made by hot rolling, cold rolling or cold dialing. The national standard steel pipe has an important position in China's steel pipe industry. According to incomplete statistics, there are more than 240 national standard steel pipe production enterprises in China, more than 250 sets of seamless steel pipe units, and an annual production capacity of about 4.5 million tons.

Withstand pressure calculation.

1. The calculation method of the outer diameter, specification and wall thickness of the national standard seamless pipe to withstand pressure (the tensile strength of different materials of steel pipe is different):

Pressure = (wall thickness * 2 * tensile strength of steel pipe material) (outer diameter * coefficient).

2. Calculation method for calculating the outer diameter and pressure of the seamless seamless steel pipe and the wall thickness of the known seamless pipe

Wall thickness = (pressure * outer diameter * coefficient) (2 * tensile strength of steel pipe material).

3. Seamless pipe pressure coefficient expression method:

The pressure of the steel pipe p<7mpa coefficient s=8.

7 "Steel pipe pressure p< coefficient s=6.

The pressure p> coefficient of steel pipe is s=4.

Steel pipes are divided into round, square, rectangular and special-shaped steel pipes according to their cross-sectional shapes; According to the material, it is divided into carbon structural steel pipe, low-alloy structural steel pipe, alloy steel pipe and composite steel pipe. According to the use, it is divided into steel pipes for pipelines, steel pipes for engineering structures, steel pipes for thermal equipment, steel pipes for petrochemical industry, steel pipes for machinery manufacturing, steel pipes for geological drilling and steel pipes for high-pressure equipment. According to the production process, it is divided into seamless steel pipe and welded steel pipe, of which seamless steel pipe is divided into hot rolling and cold rolling.

Extended information: The elements of steel pipes are:

1.Deviation. In the production process, because the actual size is difficult to meet the requirements of the nominal size, that is, it is often greater than or less than the nominal size, the standard stipulates that there is a difference between the actual size and the nominal size. A positive deviation is called a positive deviation, and a negative deviation is called a negative deviation.

2.Length of delivery.

The length of delivery is also known as the length requested by the user or the length of the contract. Typical length (also known as non-fixed-length): Any length that does not have a fixed-length requirement within the length range specified in the standard is called a general length.

3.Ellipticity.

There is a phenomenon of unequal outer diameter in the cross-section of the circular steel pipe, that is, there is a maximum and minimum outer diameter that is not necessarily perpendicular to each other, and the difference between the maximum and minimum outer diameter is ellipticism (or roundness). In order to control ovality, some steel pipe standards specify the allowable index of ovality, which generally does not exceed 80% of the tolerance of the outer diameter.