Road vehicles - Polyamide (PA) tubing for air braking systems
1 Scope
This document specifies the terms and definitions, materials and structure, technical requirements, test methods, inspection rules, as well as the requirements for the marking, packaging, transport and storage of polyamide (PA) tubing and tube assemblies for air braking systems of automobiles.
This document is applicable to air braking tubing system for automobiles with a maximum working pressure of 1.25 MPa and below, and a working temperature of -40℃ to 100℃.
This document does not apply to spiral polyamide tubing assemblies for air braking systems between tractors and trailers.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. The following documents contain provisions which, through reference in this text, constitute provisions of this document.
GB/T 1033.1-2008 Plastics - Methods for determining the density of non-cellular plastics - Part 1: Immersion method, liquid pyknometer method and titration method
GB/T 1040.2-2006 Plastics - Determination of tensile properties - Part 2: Test conditions for moulding and extrusion plastics
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 (PA) tubing without fittings, which may be of specified or non-specified length
3.2
multi-layers tubing
polyamide (PA) tubing without fittings, which is made of materials of different properties and types, and constructed of two or more layers
3.3
fitting
connecting pieces for joining tubing to tubing joints, including cutting ferrules, bushings, union nuts, and quick change couplers
3.4
tube assembly
tubes fitted with suitable end fittings
4 Material and structure
4.1 Material
The tubing shall be made of polyamide 11, polyamide 12 or polyamide 1012 (referred to as PA11, PA12 or PA1012). See Annex A for the property requirements of the materials used for the tubing.
4.2 Structure
The tubing shall be of extruded single- or multi-layer structure. The tubing of single-layer structure shall be made of the same material as specified in 4.1, and the main body of the tubing of multi-layer structure shall be made of the material specified in 4.1.
5 Technical requirements
5.1 Appearance quality
The inner and outer surface of the tubing shall be smooth and free from pits, scratches, cracks and inhomogeneities and other manufacturing defects that may affect its use. PA tubing shall be uniform in color.
5.2 Specification, dimension and tolerance
The specification, dimension and tolerance of the tubing shall meet the requirements of Table 1.
Table 1 Specification, dimension and tolerance of tubing In
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Material and structure
5 Technical requirements
6 Test methods
7 Inspection rules
8 Marking
9 Packaging, transport and storage
Annex A (Informative) Properties of materials of types PA11, PA12 and PA1012
Annex B (Normative) Impact device
