GB/T 26081-2022Ductile iron pipes, fittings and accessories for sewerage applications (English PDF)

foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1.Structure and Drafting Rules for Standardization Documents"

drafting.

This document replaces GB/T 26081-2010 "Ductile Iron Pipes, Fittings and Accessories for Sewage". Compared with GB/T 26081-2010, except

Apart from structural adjustments and editorial changes, the main technical changes are as follows.

--- Increased and changed the description of some terms and definitions (see Chapter 3, Chapter 3 of the.2010 edition);

---Change the specified upper limit of the nominal diameter of the pipeline from DN2600 to DN3000, and add the relevant specifications of DN2800 and DN3000

Technical requirements (see 4.1.1.2, 4.1 of the.2010 edition);

--- Added the technical requirements for grading pipes according to their wall thickness (see 4.2.1);

---Changed the corresponding specification range of the preferred pressure level, and basically ensured that the wall thickness of the pipe in this document is consistent with ISO 7186 and

Harmonization of GB/T 13295 (see 4.2.5, 5.1.4 of the.2010 edition);

--- Deleted the technical requirements for gravity flow tubes (see 5.1 of the.2010 edition);

---Changed the zinc coating weight requirements for pressure rating pipes in low-corrosion environment (see 4.6.2.1, 6.2.2.1 of the.2010 edition);

--- Added the requirement that aluminate cement mortar lining should be used for conveying sewage, and added the identification method of aluminate cement mortar lining

Law (see 4.6.3.1 and Appendix G);

--- Added the requirements for the seal type test of the interface under cyclic pressure (see 5.1.5);

--- Increased inspection well structure, size requirements and test methods (see 4.4, 6.5.1.3 and 10.2.7).

This document is modified to adopt ISO 7186.2011 "Ductile Iron Products for Drainage Engineering".

Compared with ISO 7186.2011, this document has more structural adjustments. For the comparison list of structural number changes between the two documents, see

Appendix A.

Compared with ISO 7186.2011, this document has more technical differences, and vertical single

Lines (|) are marked. See Appendix B for a list of these technical differences and their causes.

The following editorial changes have been made to this document.

---Modify the name of the standard to "Ductile Iron Pipes, Fittings and Accessories for Drainage Engineering";

--- Added Appendix C (informative) allowable pressure;

--- Increased the size of the pressure grade pipe in Appendix D (informative);

--- Changed Appendix F (informative) external anti-corrosion;

--- Changed the internal anti-corrosion of Appendix H (informative);

--- Added Appendix I (informative) safety factor;

--- Added Appendix K (informative) on-site inspection and acceptance.

Please note that some contents of this document may refer to patents. The issuing agency of this document assumes no responsibility for identifying patents.

1 Scope

This document specifies the requirements for ductile iron pipes, fittings and accessories for external drainage works of buildings produced by any casting process or processing

Technical requirements, performance requirements, testing methods, type tests, inspection rules, marks, quality certificates and dimension tables, etc.

This document applies to those containing sockets, spigots or flanges, generally delivered in the internal and external coated state, the size range is nominal diameter

DN80~DN3000 ductile iron pipes, pipe fittings (hereinafter referred to as "pipes" and "pipe fittings") and accessories, the scope of application is as follows.

---Operate under no pressure, positive pressure or negative pressure;

---Installed on the ground or underground;

---Split transport or combined transport of rainwater, sewage, and certain types of industrial wastewater.

2 Normative references

The contents of the following documents constitute the essential provisions of this document through normative references in the text. Among them, dated references

For documents, only the version corresponding to the date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to

this document.

GB/T 41-2016 Type 1 hex nuts, grade C (ISO 4034.2012, MOD)

GB/T 201 aluminate cement

GB/T 205 Aluminate cement chemical analysis method

GB/T 228.1 Tensile tests on metallic materials - Part 1.Test methods at room temperature (GB/T 228.1-2021, ISO 6892-1.

2019, MOD)

GB/T 231.1 Brinell hardness test for metallic materials - Part 1.Test method (GB/T 231.1-2018, ISO 6506-1.

2014, MOD)

GB/T 2988-2012 high alumina brick

GB/T 5780-2016 Hexagon head bolts, grade C (ISO 4016.2011, MOD)

GB/T 13295 Ductile iron pipes, fittings and accessories for water and gas (GB/T 13295-2019, ISO 2531.2009, MOD)

GB/T 17241.6 integral cast iron flange

GB/T 17456.1 Zinc coating on the outer surface of ductile iron pipes Part 1.Metallic zinc coating with finishing layer (GB/T 17456.1-

2009, ISO 8179-1.2004, IDT)

GB/T 17456.2 Zinc coating on the outer surface of ductile iron pipes Part 2.Zinc-rich paint coating with finishing layer (GB/T 17456.2-

2010, ISO 8179-2.1995, MOD)

GB/T 17457 Ductile iron pipes and fittings cement mortar lining (GB/T 17457-2019, ISO 4179.2005, MOD)

GB/T 17671 Test method for cement mortar strength (ISO method) (GB/T 17671-2021, ISO 679.2009, MOD)

GB/T 21873 Specifications for materials of rubber seals for water supply, drainage pipes and sewage pipes (GB/T 21873-

2008, ISO 4633.2002, MOD)

GB/T 23858 inspection manhole cover

GB/T 36173 Design regulations and type tests for self-anchoring interface systems for ductile iron pipelines (GB/T 36173-2018,

ISO 10804.2010, MOD)

GB/T 50125 Basic Terminology Standards for Water Supply and Sewerage Engineering