GB/T 18033-2017Seamless copper tubes for water and gas (English PDF)

3.1 Nominal diameter

The general diameter between various pipes and fittings, which is the diameter expressed as an integer value close to the actual inner diameter of the pipe. Pipe and fitting mouth The paths are consistent so that they can be connected to each other.

Note: The nominal diameter is usually expressed by DN, followed by the nominal diameter of the nominal diameter in mm.

4.1 Product Classification

4.1.1 Grade, status, specifications

The grade, condition and specifications of the pipe shall comply with the requirements of Table 1.

4.1.2 Tag example

Product marks are expressed in the order of product name, standard number, grade (or code), status, and specifications. Examples of tags are as follows.

Example 1. Manufactured by TP2 (C12200), the supply state is pull (hard) state (H80), outer diameter is 108mm, wall thickness is 1.5mm, length is 5800mm The round copper tube is marked as.

Copper tube GB/T 18033-TP2H80-Phi108×1.5×5800 Or copper tube GB/T 18033-C12200H80-Phi108×1.5×5800

Example 2. A round copper coil manufactured by TU2 (T10180) with a softened annealed O60, an outer diameter of 22 mm and a wall thickness of 0.8 mm is marked as.

Copper coil GB/T 18033-TU2O60-Phi22×0.9 Or copper coil GB/T 18033-T10180O60-Phi22×0.9

4.2 Chemical composition

The chemical composition of the pipe shall comply with the corresponding grades in GB/T 5231.

4.3 Dimensions and their allowable deviation

4.3.1 The dimensions and allowable deviation of the pipe shall comply with the requirements of Table 2.

4.3.2 The allowable deviation of the length of the straight pipe is ±10mm, and the allowable deviation of the length of the coil is 300mm. Straight pipe length is fixed length, double For the length of the ruler, the amount of sawing when sawing the segment should be added, and each sawing amount is 5 mm.

4.3.3 The straightness of the straight (hard) (H80) and light pull (H55) or pull (H58) straight pipes with an outer diameter not greater than Phi108mm shall comply with Table 3.

The stipulation that the outer diameter is greater than the straightness of the Phi108mm pipe is determined by the supplier and the buyer.

4.3.4 The end of the straight pipe shall be sawed and leveled, and the incision shall not exceed the requirements of Table 4 without causing the pipe length to exceed the allowable deviation. The slope of the cut.

4.3.5 The roundness of the drawn straight pipe without annealing shall comply with the requirements of Table 5.

4.4 Mechanical properties

The longitudinal mechanical properties of the pipe at room temperature are to comply with the requirements of Table 6.

4.5 Grain size

The average grain size of soft-annealed (O60) tubing should be 0.020mm~0.045mm, and the average grain size of light annealed (O50) tubing should be It is 0.015mm~0.035mm.

4.6 Process performance

4.6.1 Flaring (squashing) test

Softening annealing (O60), light annealing (O50), pull (H58), and light pull (H55) pipes with an outer diameter of not more than 18 mm for flaring test Inspection time, the top cone is 45 °, the expansion rate is 40%; the outer diameter is greater than 18 mm soft annealing (O60), light annealing (O50), pull (H58), light pull When the (H55) state pipe was subjected to the flare test, the top cone was 45° and the flare ratio was 30%. The flattening test can be used instead of the flaring test, and the flattened pipe can be used.

The inner wall spacing is equal to 3 times the wall thickness.

After the flaring (squashing) test, the pipe shall not show cracks or breakage visible to the naked eye.

4.6.2 Bending test

For a drawn (hard) (H80) tube with an outer diameter of not more than 28 mm, the bending test shall be carried out according to the bending radius specified in Table 7. The bending angle is 90°, bent with a special tool. After the test, the pipe should have no defects such as cracks or breakage visible to the naked eye.

4.7 Non-destructive testing

Each pipe shall meet the requirements of hydrostatic test or air pressure test or eddy current test (one of three choices).

a) Hydraulic test The maximum working pressure of the pipe is calculated according to formula (1). The maximum working pressure that the pipe can withstand is shown in Table 2.

When the pipe is subjected to hydrostatic test, the test pressure is calculated according to formula (2). Under the working pressure, after 10 s to 15 s, the pipe should be No leakage and permanent deformation.

b) air pressure test When the pipe is subjected to air pressure test, the air pressure is 0.4 MPa, the pipe is completely immersed in water for at least 10 s, and the pipe should be free of air bubbles. appear.

c) Eddy current testing When the wall thickness of the pipe is <=3mm, the eddy current testing shall be carried out. The artificial standard defects (drilling diameter) and the flaw detection results shall be consistent. GB/T 5248 provisions.

4.8 Surface quality

The inner and outer surfaces of the pipe should be smooth and clean, and should not have harmful defects affecting the use. The inner surface should not have a carbon film.

5.1 Chemical composition

The chemical composition analysis method of the pipe is carried out according to the provisions of GB/T 5121 (all parts) or YS/T 482, and the chemical composition of the pipe is The analysis is carried out in accordance with the provisions of GB/T 5121 (all parts).

5.2 Dimensions

The measuring method of the outer dimensions of the pipe is carried out in accordance with the provisions of GB/T 26303.1.

5.3 Mechanical properties

The tensile test method of the pipe is carried out according to the provisions of GB/T 228.1-2010. The Vickers hardness of the pipe is in accordance with the provisions of GB/T 4340.1. get on. Tensile specimens shall comply with the provisions of Appendix E of GB/T 228.1-2010, and their shape and size shall be selected according to the following provisions.

a) If the outer diameter is not more than 30mm, cut the full-section pipe section from the pipe and select the sample No. S7;

b) If the outer diameter is larger than 30mm, longitudinal longitudinal specimens may be taken, and samples S1 and S2 may be selected.

5.4 Grain size

The grain size of the pipe is carried out in accordance with the provisions of YS/T 347.

5.5 Process performance

5.5.1 The flaring test of the pipe shall be carried out in accordance with the provisions of GB/T 242.

5.5.2 The flattening test of the pipe shall be carried out in accordance with the provisions of GB/T 246.

5.5.3 The bending test of the pipe is carried out in accordance with the provisions of GB/T 244.

5.6 Non-destructive testing

5.6.1 Hydraulic test

The hydraulic test of the pipe is carried out in accordance with the provisions of GB/T 241.

5.6.2 Air pressure test

The air pressure test of the pipe should be kept connected to the air source with pressure to keep the air with a certain pressure in the pipe. Complete the pipe Immerse in water and check for air bubbles from the tubing.

5.6.3 Eddy current testing

The eddy current testing method for pipes is carried out in accordance with the provisions of GB/T 5248.

5.7 Surface quality

The method for detecting the carbon film on the inner surface of the pipe shall be carried out in accordance with the provisions of Appendix A. The other surface quality of the pipe is checked visually.

6.1 Inspection and acceptance

6.1.1 Pipes shall be inspected by the technical supervision department to ensure that the product quality meets the requirements of this standard and fill in the quality certificate.

6.1.2 The purchaser shall re-examine the products received in accordance with the provisions of this standard. The results of the re-inspection shall not be in accordance with the provisions of this standard and the order form (or contract).

When signing, it shall be submitted to the supplier in writing and resolved by negotiation between the supplier and the buyer. Objections that are subject to surface quality and dimensional deviation should be received Presented within one month from the date of the product. If arbitration is required, the arbitration sampling shall be carried out jointly by the supplier and the buyer.

6.2 Batch

Pipes shall be submitted for acceptance in batches. Each batch shall consist of the same grade, state and specifications, and the weight of each batch shall not exceed 5000kg.

6.3 Inspection items

6.3.1 The chemical composition, dimensions and tolerances, mechanical properties, process properties, non-destructive tests, grain size of each batch of tubing shall be carried out. And inspection of surface quality.

6.3.2 When required, the Vickers hardness and carbon film shall be tested.

6.4 Sampling

Pipe sampling shall comply with the requirements of Table 8. The sampling method shall be carried out in accordance with the provisions of YS/T 668. The mechanical properties and process properties shall be prepared according to the sample. The YS/T 815 regulations are carried out.

6.5 Determination of test results

6.5.1 If the chemical composition is unqualified, the batch of pipe is judged to be unqualified.

6.5.2 If the outer dimensions and surface quality of the pipe (except the carbon film) are unqualified, the root shall not be qualified. The number of unqualified parts in each batch exceeds the receiving quality When the quantity limit is determined, the whole batch is unqualified, or the supplier is inspected one by one, and the qualified one delivers.

6.5.3 When the test results of mechanical properties, process properties, grain size, carbon film test, etc. are unqualified, double samples shall be taken from the batch of products.

Repeat the test for this unqualified item. If the repeated test results are all qualified, the whole criticism is qualified; if there is still a sample in the repeated test If it is unqualified, it will be criticized as unqualified, or it will be tested by the supplier one by one, and the qualified person will deliver it.

6.5.4 If the non-destructive test fails, the individual pipe is judged to be unqualified.

7.1 Identification

7.1.1 Classification

The pipes that have passed the inspection shall be marked one by one on the outer surface of each pipe, and the marks shall be divided into. permanent marks or durability marks.

7.1.2 Permanent identification

Each copper pipe shall have a permanent mark within a 0.6m spacing. The height of the letter shall comply with the requirements of Table 9. The contents include.

a) the manufacturer's name or trademark;

b) brand, status, specifications;

c) wall thickness type (A, B, C);

d) standard code;

e) the export country should indicate the name of the country of origin;

f) Date of manufacture. year, month (×× weeks);

g) Other marks.

7.1.3 Durability marking

The durability logo is as follows.

a) Each straight pipe shall be marked with the same color only for the length of the length of the pipe and shall be printed repeatedly at intervals of 1.0 m. See 7.1.2 for text content and height.

b) Color regulations.

Copper water pipes. type A --- green; type B --- blue; C type --- red. Copper gas pipe. yellow.

7.2 Packaging, transportation, storage and quality certificate

The packaging, transportation, storage and quality certificate of the pipe shall be carried out in accordance with the provisions of GB/T 8888.

A.1 Scope

This appendix specifies the qualitative detection method for the carbon film on the inner surface of copper tubes.

This appendix applies to the detection of carbon film on the inner surface of copper tubes.

A.2 Method summary

The copper tube sample was treated with a 25% aqueous solution of nitric acid at room temperature, and the inner surface of the copper tube was determined by observing whether or not a film-like substance was formed on the surface of the acid liquid. Whether there is a carbon film on the surface.

A.3 Sample

Take a sample tube with a length of not less than 25 mm.

A.4 Test procedure

A.4.1 Preparation of samples

The outer surface of the pipe sample used for the test shall be cleaned, and the wear marks caused by the metal chips shall remove or eliminate all traces of the surface of the original pipe.

Chemically, one end of the nozzle can be plugged with an acid-resistant stopper, immersed in a nitric acid solution, then washed with deionized water and dried.

The sample tube is cut into two test pieces in the longitudinal direction with a clean saw blade, and the test piece should have a surface size larger than 22 mm × 1 mm, and The sample block was degreased with acetone.

A.4.2 Treatment of samples

Place the degreased sample block into a small flat bottom porcelain plate or glass plate with the inner surface of the sample facing up and add at room temperature. 25% (volume fraction) of nitric acid, submerged the sample block.

Nitric acid will float the surface of the sample. When the acid turns blue, the sample block should be taken out and rinsed with deionized water and returned to acid.

Wash any small substances on the sample block in the liquid.

A.5 Determination of carbon film

The reaction of the sample block in acid was observed using a 10x magnifying glass. Observation will assess the reaction of the material in the acid.

a) If no phenomena are found, or only tiny substances are seen, it is determined that there is no carbon film.

b) If it is clear that a film floats on the surface, it may be a carbon film or an oxide film.

c) In order to distinguish between carbon film and oxide film, the porcelain plate or glass plate should be slowly heated to boil the acid for about 5 minutes. As in the re In the heating test, when the film was decomposed or only a small substance remained, it was judged to be an oxide film. If the film does not change, then determine It is a carbon film.