GB/T 41494-2022Aluminum alloy lining plastics pipes and fittings (English PDF)

3.1 Terms and Definitions

For the purposes of this Document, the following terms and definitions apply.

3.1.1 Aluminum alloy lining plastic pipe

The pipe with the outside pipe of an aluminum alloy tube, and the inside pipe of a thermoplastic (PP-R, PB, PE-RT, PE) pipe, and is prestressed and compounded to form a two-layer structure.

3.1.2 Outside pipe

The outer structure of the aluminum alloy lining plastic pipe, which is a seamless aluminum alloy round-pipe formed by hot extrusion.

3.1.3 Inside pipe

L1: Minimum socket depth of hot-melt socket fitting; L2: Minimum insertion depth of hot-melt socket fitting;

L3: Tubular length of the fusing section of the hot-melt butt fitting socket;

L4: The cutback length of the fusing section of the hot-melt butt fitting socket; L5: The socket depth of electrofusion connection fitting;

L6: The length of the fusing zone of the electrofusion connection fitting; S: Pipe series; TD: Design temperature; Tmal: Malfunction temperature; Tmax: Maximum design temperature.

3.2.2 Abbreviations

MFR: Melt Mass-Flow Rate; PB: Polybutylene; PE: Polyethylene; PE-RT: Polyethylene of Raised Temperature Resistance; PP-R: Polypropylene Random Copolymer; SDR: Standard Dimension Ratio.

4.1 Material of pipe

4.1.1 Take the wrought aluminum alloy as the material of outside pipe; its chemical composition shall comply with the provisions of GB/T 3190; and its mechanical properties shall comply with the provisions of GB/T 4437.1.

4.1.2 When the inside pipe is a polypropylene random copolymer (PP-R) pipe, the material properties of the inside pipe raw material shall comply with the provisions of GB/T 18742.2.

4.1.3 When the inside pipe is a polybutene (PB) pipe, the material properties of the inside pipe raw material shall comply with the provisions of GB/T 19473.2.

8.3.1.4 Thickness of anodic oxide film and outer plastic coating

The thickness of the anodic oxide film is measured in accordance with the provisions of GB/T 8013.1; and the thickness of the outer plastic coating is measured by a measuring tool with an accuracy of no less than 0.02mm.

8.3.2 Fitting

8.3.2.1 Minimum diameter

Measure in accordance with the provisions of GB/T 8806.

8.3.2.2 Wall thickness

Measure in accordance with the provisions of GB/T 8806.

8.3.2.3 Depth of fusing socket of fitting

According to the provisions of GB/T 8806, use a measuring tool with an accuracy of no less than 0.02mm to measure.

8.3.2.4 Average inner diameter

Measure in accordance with the provisions of GB/T 8806.

8.3.2.5 Average outer diameter

Measure in accordance with the provisions of GB/T 8806.

8.3.2.6 Tubular length and cutback length of butt fitting

In accordance with the provisions of GB/T 8806, use a measuring tool with an accuracy of no less than 1mm to measure.

8.3.2.7 Non-roundness

Measure in accordance with the provisions of GB/T 8806.

8.4 Hydrostatic test

Carry out the test in accordance with the provisions of GB/T 6111, use the A-typed head.

8.5 Thermal stability test under hydrostatic state

8.5.1 Test conditions

Test according to the provisions of Tables 7, 8 and 9 respectively, and the allowable temperature deviation is 110+4 -2 °C. Test medium: water inside and air outside.

8.5.2 Test method

Carry out the test in accordance with the provisions of GB/T 6111, using the A-type head.

8.6 Melt mass flow rate

Carry out the test in accordance with the provisions of GB/T 3682.1.

8.7 Oxidation induction time

Carry out the test in accordance with the provisions of GB/T 19466.6.

8.8 Hygienic performance test

Carry out the test in accordance with the provisions of GB/T 17219.

8.9 Internal pressure test

Carry out the test in accordance with the provisions of GB/T 6111.

8.10 Hot and cold cycle test

Carry out the test in accordance with the provisions of GB/T 18991.

9.1 Inspection classification

Inspection is divided into stereotype inspection, exit-factory inspection and type inspection.

9.2 Batching and grouping

9.2.1 Pipe

The same batch of raw materials and pipes continuously produced with the same specification shall be regarded as a batch; and the quantity of each batch shall not exceed 150t. When the production of 7d is less than 150t, the output of 7d is regarded as a batch.

9.2.2 Fitting

Fittings that are produced continuously with the same batch of raw materials, the same production process and the same specification are regarded as a batch. The quantity of each batch shall not exceed 10,000 pieces; when the production of 7d is still insufficient for a batch, the production of 7d shall be regarded as a batch.

9.6 Judgment rules

Appearance and dimensions in Clause 7 are determined according to Table 15. If there is one unqualified hygienic requirement, it shall be judged as unqualified batch (or product). If one of the other requirements fails to comply with the provisions, double quantities of samples shall be randomly selected for reinspection. If it is still unqualified, it shall be judged as an unqualified batch (or product).

10.1 Marking

10.1.1 Marking of pipe

There shall be a complete and permanent marking on each pipe, and the distance between the markings shall be no greater than 2m. The pipe marking shall contain at least the following:

a) Trademark or manufacturer's name;

b) Product name and specification;

c) This document number;

d) Production date or production batch number.

For pipeline systems for gas transmission, the words "Ranqi (Pinyin)" and "GAS" shall be marked.

10.1.2 Marking of fitting

There shall be complete and permanent marking on each fitting. The fitting markings shall at least contain the following:

a) Trademarks;

b) Name of raw material;

c) Product specification, indicate the pipe series (S).

For pipeline systems used for gas transmission, the name and grade of raw materials shall be marked.

10.2 Packaging

10.2.1 The pipes shall be packed, bundled and sealed according to the same specifications, and can also be negotiated according to user requirements. The pipe packaging shall at least contain