1 Scope
This part of GB/T 28799 specifies terms and definitions, materials, requirements, test methods, inspection rules, marking, packaging, transport and storage of buried polyethylene (PE) pipes made through extrusion with PE compounds as raw materials and used for supply of gaseous fuels.
This part covers the following types of pipes:
——Solid-wall pipes with single layer;
——Pipes with a peelable thermoplastics protective layer on the outside.
This part is applicable to buried polyethylene (PE) pipes with nominal outside diameter of 16 mm ~ 630 mm made of PE 80 and PE 100 compounds and used for supply of gaseous fuels; the maximum operating pressure (MOP) of the pipes is determined based on the design stress, and taking into account rapid crack propagation (RCP) requirements.
During the transmission of manufactured gas and liquefied petroleum gas, the adverse effects of some components, such as aromatic hydrocarbon and condensed fluid, in gaseous fuels under certain concentration on pipe characteristics shall be considered.
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 321 Preferred Numbers - Series of Preferred Numbers (GB/T 321-2005; ISO 3: 1973, IDT)
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 (ISO 1183-1: 2004, IDT)
GB/T 1033.2-2010 Plastics - Methods for Determining the Density of Non-cellular Plastics - Part 2: Density Gradient Column Method (ISO 1183-2: 2004, MOD)
GB/T 2828.1 Sampling Procedures for Inspection by Attributes - Part 1: Sampling Schemes Indexed by Acceptance Quality Limit (AQL) for Lot-by-lot Inspection (GB/T 2828.1-2012; ISO 2859-1: 1999, IDT)
GB/T 2918
Plastics - Standard Atmospheres for Conditioning and Testing (GB/T 2918-1998, idt ISO 291: 1997)
GB/T 3681-2011 Plastics - Methods of Exposure to Direct Weathering, to Weathering Using Glass-filtered Daylight, and to Intensified Weathering by Daylight Using Fresnel Mirrors (ISO 877: 1994, IDT)
GB/T 3682-2000 Determination of the Melt Mass-flow Rate (MFR) and the Melt Volume-flow Rate (MVR) of Thermoplastics (idt ISO 1133: 1997)
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Material
5 Requirements
6 Test Method
7 Inspection Rules
8 Marking
9 Packaging, Transport and Storage
Annex A (Informative) Structural Changes of this Part Compared with ISO 4437-1:2014 and ISO 4437-2:
Annex B (Informative) Technical Differences of this Part and Causes with Respect to ISO 4437-1:2014 and ISO 4437-2:
Annex C (Informative) Pressure Reduction Coefficient at Operating Temperature
Annex D (Informative) PE 100 Compounds and Pipes with High Characteristics of Resistance to Slow Crack Growth
Annex E (Normative) Pipes with Peelable Layer
Annex F (Normative) Test Method of Compression and Recovery
Bibliography
