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Stainless steel Coiled Capillary Tubing Quality Control Test Methods
May 08, 2017

1.    Specification references

The following documents are indispensable for the application of this document. For dated references, only the dated edition applies to this document, and the most recent version of the referenced document (including all amendments) applies to documents that are not dated.


 GB/T 222                                Chemical composition allows deviation

 GB/T 223 Series                    Methods for chemical analysis of steel and alloys

 GB/T 228.1                             Metallic materials - Tensile testing 

 GB/T 230.1                            Metallic materials - Rockwell hardness test

 GB/T 241                                Hydraulic test method for stainless Capillary pipe

 GB/T 246                                flattening test method for stainless Capillary pipe

 GB/T 2102                             Acceptance, packing, marking and quality certificate of stainless coiled                                                    Capillary tubing

 GB/T 3090                             Stainless steel small diameter seamless pipe

 GB/T 11170                           Determination of multi-element content of stainless steel coiled tubing

     2.    Terms and definitions

The following terms and definitions apply to this standard

     3.1 Control

Stainless steel coiled capillary tubing is mainly used in hydraulic control system, it must go through the hydraulic test, the coiled pipe to 7.0MPa for the test pressure.

     3.2 Name

 

SAKY—8X1X300 (304)

OD 8mm Thickness 1mm Length 300m Material 304*Sasamtetal coiled capillary tubing. Remark *: Material base on 4.2 request test

4 Request

4.1 Stainless steel coiled capillary tube shall be manufactured in accordance with the technical documents approved by the prescribed procedures and shall comply with the requirements of this standard.

4.2 For the manufacture of stainless capillary tubing line of the material, the chemical composition should be consistent with Table 1, the mechanical properties should be consistent with the provisions of Table 2. If the customer has the special requirements, according to customer requirements, the chemical composition of the product, mechanical properties should meet the requirements of the corresponding standards.

 

Table 1  Coiled Capillary Chemical Composition

Grade

Chemical   Composition

C  ≤

Mn ≤

P ≤

S ≤

Si ≤

Ni

Cr

Mo

Ti

304

0.07

2.00

0.035

0.03

1.00

8.0011.00

17.0019.00

316

0.08

2.00

0.035

0.03

1.00

10.0014.00

16.0018.00

2.003.00

 

Table 2  Coiled Capillary mechanical properties

Grade

Tensile   Strength

Elongation   after breaking

Hardness   test

RM(MPa)   ≥

A% ≥

HV≤

304

520

35

260

316

481

35

260

 

4.3  Surface treatment state and surface quality

 Stainless steel coiled capillary tubing should be bright treatment, inside and outside the surface should be smooth, no stratification, cracks, folding, miscellaneous skin, twisted, etc., allowed to have no more than a slight tolerance of wall thickness of the slight scratch, pressure pit, Depression, protrusion and so on.

4.4 Geometric dimensions

4.4.1 Stainless steel coiled capillary tubing length,outside Diameter, wall thickness and other requirements should be consistent with the provisions of Table 3.

4.4.2 Table 3 shows the OD of the deviation is not sufficient to indicate the thin-walled tube oval. The deviation between the maximum and minimum diameters of the cross sections of these control pipes shall not exceed 200% of the allowable deviation of the outer diameters listed in Table 3, and the average diameter of any section shall be within the permissible deviation.

Table 3  Geometric dimensions & Allow deviation

SN

ODmm

DO Allow   deviationmm

Thickness   Allow deviationmm

1

Φ 3

±0.05

±0.06

2

Φ   3.175

±0.05

±0.06

3

Φ 6

±0.08

±0.08

4

Φ   6.35

±0.08

±0.08

5

Φ 8

±0.08

±0.08

6

Φ 10

±0.1

±0.1

7

Φ 12

±0.1

±0.1

 

 

4.5 Flattening performance

      Stainless steel coiled capillary tubing flattening test, the welding should be in the direction of force 90 °, pressure to the pipe OD of 2/3, No cracks or cracks may occur after crushing.

4.6 Hydraulic performance

      Stainless steel coiled capillary tubing by the pressure of 7.0MPa, and pressure 5mins pressure test, should be no leakage

4.7 Intergranular corrosion

   Stainless steel coiled capillary tubing immersed in sulfuric acid pool for 16h, 180 ° bending, no intergranular corrosion cracking.

4.8 Raw Material Request

4.8.1 The raw materials of the products shall conform to the relevant standards

4.8.2 Raw materials should be selected with product standards and factory inspection of qualified products, each batch of raw materials should be tested before use before use

5. Test Methods

5.1 Hardness

5.1.1 Each batch of stainless steel capillary pipe must be sampled and tested according to GB / T 230.1 for hardness testing

5.1.2 Each batch of sampled stainless steel coiled tubing in the test, sampling tube head, tail each time, each test must be in the same sample on the 4 point test.

 

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