QC/T 80-2022 English PDF (QCT80-2022)
QC/T 80-2022 English PDF (QCT80-2022)
QC/T 80-2022: Road vehicles - Polyamide(PA) tubing for air braking systems
AUTOMOBILE INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
CCS T 24
Road vehicles - Polyamide (PA) tubing for air braking
ISSUED ON: APRIL 08, 2022
IMPLEMENTED ON: OCTOBER 01, 2022
Issued by: Ministry of Industry and Information Technology of the People's Republic of China
Table of Contents
Foreword ... 8
1 Scope ... 10
2 Normative references ... 10
3 Terms and definitions ... 11
4 Material and structure ... 11
5 Technical requirements ... 12
6 Test methods ... 16
7 Inspection rules ... 27
8 Marks ... 28
9 Packaging, transportation and storage ... 29
Annex A (informative) Properties of PA11, PA12, PA1012 materials ... 30 Annex B (normative) Impact devices ... 31
Road vehicles - Polyamide (PA) tubing for air braking
This document specifies the terms and definitions, materials and structures, technical requirements, test methods, inspection rules, marks, packaging, transportation and storage requirements for polyamide tubing and tubing assemblies used for air braking systems.
This document is applicable to the air braking pipeline system, of which the maximum working pressure is 1.25MPa and below, and the working temperature is -40°C~100°C. This document does not apply to the polyamide spiral tube assembly for the air braking system between the tractor and the trailer.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 1033.1-2008, Plastics - Methods for determining the density of non-cellular plastics - Part 1: Immersion method, liquid pycnometer method and titration method GB/T 1040.2-2006, Plastic - Determination of tensile properties - Part 2: Test conditions for moulding and extrusion plastic
GB/T 1043.1-2008, Plastics - Determination of Charpy impact properties - Part 1: Non-instrumented impact test
GB/T 1690-2010, Rubber, vulcanized or thermoplastic - Determination of the effect of liquids
GB/T 2408-2008, Plastics - Determination of burning characteristics - Horizontal and vertical test
GB/T 2828.1-2012, Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 12006.1-2009, Plastics - Polyamides - Part 1: Determination of viscosity number
GB/T 16422.2-2014, Plastics - Methods of exposure to laboratory light sources - Part 2: Xenon-arc sources
GB/T 16422.4-2014, Plastics - Methods of exposure to laboratory light sources - Part 4: Open-flame carbon-arc lamps
GB/T 19466.3-2004, Plastics - Differential scanning calorimetry (DSC) - Part 3: Determination of temperature and enthalpy of melting and crystallization GB 29518, Diesel engines NOx reduction agent - Aqueous urea solution (AUS 32) QC/T 798-2008, Multi-layers plastic tubing for automotive fuel system
QC/T 1043-2016, Automotive fuel system nylon tube
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. 3.1 tubing
polyamide tubing of specified or unspecified length without fittings
3.2 multi-layers tubing
two or more layers of polyamide tubing that is made of different types of materials with different properties, without fittings
ferrules, bushings, union nuts, push-in connectors and other connecting parts used to connect tubing and pipe joint bodies
3.4 tube assembly
tubing fitted with suitable end fittings
4 Material and structure
The material for making the tubing is polyamide 11, polyamide 12 or polyamide 1012 (referred to as PA11, PA12 or PA1012). Refer to Annex A for the performance requirements of the material used in the tubing.
(cut the desired length from the rewind area; the necessary length for the burst strength test shall include the portion of the tubing at high temperature).
6.7 Impact performance
6.7.1 Low temperature impact
220.127.116.11 Test devices
See Annex B for the impact test devices.
18.104.22.168 Test steps
Place the straight tubing specimen in a low temperature box at -40°C±2°C for 2h. Take out the specimen. Under the ambient temperature of 23°C±2°C, the impact test shall be carried out in accordance with the provisions of GB/T 1043.1-2008 within 5s. 6.7.2 Impact after resistance to high temperature
22.214.171.124 Test devices
See Annex B for the impact test devices.
126.96.36.199 Test steps
Place the specimen in a high-temperature box at 150°C±2°C for 72h. Then cool to 23°C±2°C. After stabilizing at this temperature for 4h, carry out the impact test according to the provisions of GB/T 1043.1-2008.
6.8 Interlayer adhesion of multi-layers tubing
Carry out the test in accordance with the provisions in 7.11.1 of QC/T 798-2008. 6.9 Water absorption
Place the specimen in a high temperature box at 100°C±2°C for 24h. Take it out. Put it in a desiccator down to room temperature and weigh it (accurate to 0.001g). Then place the specimen in water at 23°C±2°C for 100h. Then immediately take out the specimen. Use filter paper to wipe off the water on the inner and outer surfaces of the specimen. Weigh it again (accurate to 0.001g). Calculate water absorption according to formula (1).
ΔW - Water absorption, %;
W1 - Mass before water absorption, in grams (g);
W2 - Mass after water absorption, in grams (g).
6.10 Ethanol resistance
Bend the specimen at least 180° to the mandrel specified in Table 6. Keep the shape. At an ambient temperature of 23°C±2°C, immerse the specimen in 95% ethanol solution. Place for 200h. Straighten the specimen after taking it out. Check the surface of the specimen for cracks.
6.11 Resistance to urea solution
Bend the specimen at least 180° to the mandrel specified in Table 6. Keep the shape. At an ambient temperature of 23°C±2°C, immerse the specimen in the urea aqueous solution specified in GB 29518 for 70h. Remove the specimen from the test solution. Rinse and wipe thoroughly. Check the surface of the specimen for cracks. 6.12 Electrolyte resistance
Weigh the specimen. Measure the outer diameter and wall thickness. Then seal both ends of the specimen. According to the mandrel specified in table 6, bent at least 180°. Keep the shape. At an ambient temperature of 23°C±2°C, immerse the specimen in a dilute sulfuric acid solution with a density of 1.275g/cm3 (concentration is 36.78%) for 70h. Remove the specimen from the solution. Thoroughly wash and wipe clean. Weigh again. Measure the outer diameter and wall thickness of the specimen at the same position. Check the surface of the specimen for cracks. Finally, attach the tubing to the fitting. Carry out the tensile strength test in accordance with 6.17.
6.13 Oil resistance
Under the condition of water temperature 23°C±2°C, measure the initial volume of the specimen whose tubing specification is 12×1.5 by water displacement method according to the provisions of GB/T 1033.1-2008. Weight accurate to 0.001g. Dry the specimen. Place it in a container filled with IRM903 standard oil specified in Table A.3 of GB/T 1690-2010 (additives in the oil shall be chemically inert to thermoplastic materials). Put the container in a 72°C±2°C high-temperature box for 70h. Then let the specimen cool down to the test ambient temperature in the test solution. Take out the specimen. Wipe the inner and outer surfaces with filter paper. Measure the final volume of the specimen in the same way as above. Calculate the volume change rate of the specimen according to formula (2).
ΔV - Volume change rate, %;
V1 - Volume before immersion in oil, in grams (g);
V2 - Volume after immersion in oil, in grams (g).
6.14 Combustion resistance
Store the specimen whose tubing specification is 12×1.5 in an environment with a temperature of 23°C±2°C and a relative humidity of 50%±5% for at least 24h. But it shall not exceed 168h. Immediately carry out the test according to the steps specified in the level method in GB/T 2408-2008.
6.15 Weather resistance
6.15.1 Test equipment
Use a suitable light source with a reproducible spectrum and constant output that complies with GB/T 16422.2-2014 or GB/T 16422.4-2014. The preferred test equipment is the arc test cabinet. Test cabinets with other types of light sources, such as open carbon arc lamps, may also be used by agreement between the tubing manufacturer and user.
6.15.2 Test steps
188.8.131.52 According to the method of GB/T 16422.2-2014 or GB/T 16422.4-2014, use 60W/m2 light to irradiate the specimen whose tubing specification is 12×l.5. Ensure that the specimen does not move during the test:
a) At the black standard temperature of 65°C±3°C, relative humidity of 65%±5%, the irradiation time of the arc lamp is 750h;
b) Under the black standard temperature of 65°C±3°C, use an open carbon arc lamp for 400h.
184.108.40.206 Water spray cycle shall be carried out during the test. The cycle mode is 18min spray water mist and 102min without spray. The relative humidity of 65%±5% refers to the relative humidity after reaching stability without spraying water. 220.127.116.11 Take out the specimen. Install end fittings. Carry out the burst strength test at room temperature in accordance with 6.4.1 on this assembly.
6.16 Pressure deformation
Condition the specimen at 23°C±2°C for 24h. Then draw a reference line about 50mm±5mm from the pipe fittings at both ends. Measure the original outside diameter and original length of the tubing between the reference lines. Fix one end of the specimen. According to Figure 1, keep the specimen in an environment of 100°C±2°C for 1h. Start applying pressure at the 55th min. Make the internal pressure of the tubing reach 125% of the maximum working pressure value during the 55th min~56th min. a) Keep the specimen at 100°C±2°C for 1h. At this temperature, apply 1.5 times the maximum working pressure to the specimen. Maintain 1min. Observe whether there are bubbles in the connection part. Return to atmospheric pressure. Cool to the ambient temperature;
b) Lower the temperature to -40°C±2°C. Maintain 4h. At this temperature, apply 1.5 times the maximum working pressure to the specimen. Maintain 1min. Observe whether there are bubbles in the connection part. Then return to the atmospheric pressure state;
c) Raise the temperature to 23°C±2°C. Maintain 1h. Apply 1.5 times the maximum working pressure to the specimen. Maintain 1min. Observe whether there are bubbles in the connection part;
d) In each case, pressure shall be applied gradually. Reach the specified value within 30s~60s.
7 Inspection rules
7.1 Conformity documents and marks
Products shall pass the inspection of the manufacturer and be accompanied by a product certificate before leaving the factory.
7.2 Inspection category
Inspection is divided into exit-factory inspection and type inspection. 7.3 Exit-factory inspection
7.3.1 The inspection items of the exit-factory inspection include appearance quality, size, identification, room temperature burst strength, low temperature impact, airtightness and tensile strength.
7.3.2 Take enough specimens according to the production batch. Inspect according to the requirements of this document.
7.3.3 When the ordering party conducts random inspection of products, it shall follow the provisions of GB/T 2828.1-2012. Sampling plan and acceptance quality level AQL value are agreed upon by both parties.
7.4 Type inspection
7.4.1 Type inspection shall be carried out in one of the following cases: a) When a new product or an old product is transferred to a factory for trial production identification;
b) After formal production, when there are major changes in structure, materials, and processes that may affect product performance;
c) When production is resumed after a long-term suspension;
d) When batched or mass-produced products are not less than once a year; e) When the exit-factory inspection results are significantly different from the previous type inspection results;
f) When the national quality supervision agency puts forward the requirements for type inspection.
7.4.2 The tubing of the same specification continuously produced at the same production site, with the same raw materials, equipment and processes shall be regarded as a batch. Products for type testing shall be selected from the same batch of products that have passed the exit-factory inspection. The sampling plan shall be agreed between the supplier and the purchaser.
7.4.3 The type inspection items are all performance items specified in Chapter 5. 7.5 Determination for qualification
Inspect according to the test method specified in this document. Make quality judgments on products based on test results and technical requirements. If there is one failed item, it is allowed to re-select double the number of products to repeat the testing. If there is still failed item, the batch of products shall be rejected. 8 Marks
Tubing conforming to the requirements of this document shall have the following marks on the outer wall along the axis of the tube diameter. The minimum height of marking character is 2mm. Repeat marking at least every 350mm. The marking content is as follows:
- Series number of the standard;
- Symbol for the type of material;
- Manufacturer’s name;
- Date of manufacture or code;
- Customer special requirements as well as legal and regulatory requirements. The above marks shall be separated from each other by slashes or spaces. 9 Packaging, transportation and storage
9.1.1 The packaging shall ensure that the product will not be damaged under normal transportation conditions.
9.1.2 The packaging shall keep the tubing and tube assembly clean. Do not allow debris to enter the tubing.
9.1.3 Each package shall be accompanied by a product certificate.
9.1.4 The outer packaging shall be marked with:
a) Manufacturer's name or trademark;
b) Product specification and drawing number;
c) Product quantity;
d) Product color.
9.2 Transportation and storage
Tubing and tube assembly shall be placed in a cool and dry place during transportation and storage. Tubing and tube assembly shall not be scratched, thrown, violently impacted, exposed to the sun, rain, oil and chemical pollution during transportation. It is forbidden to contact with corrosive substances such as acid, alkali and phenol. Well-packed products shall be stored in a ventilated and dry warehouse.