Ductile iron pipes, fittings and accessories for water or gas applications
1 Scope
This standard specifies the terms and definitions, technical requirements, test methods, dimensions and tolerances, inspection rules, quality certificate, etc. of ductile iron pipes, fittings, accessories and joints for water or gas applications cast by any type of foundry process or manufactured by fabrication of cast components, and it also gives type test requirements for all components including joints.
This standard is applicable to pipes, fittings and accessories which are manufactured with socketed, flanged or spigot ends, normally delivered externally and internally coated, with a dimension range of DN40~DN3000, suitable for fluid temperatures between 0℃ and 50℃, which are:
——used to convey water with various usages and different types;
——operated with or without pressure;
——installed below or above ground.
——used to convey gas with design pressure of class A medium pressure and below (such as artificial gas, natural gas and LPG).
This standard is not applicable to the convey of fluids with temperature below freezing temperature (which does not preclude use of the product at higher temperatures).
Pipes and fittings are classified according to allowable operating pressure or wall thickness.
Note: All pressures in this standard are relative and are expressed in MPa.
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 (including any amendments) applies.
GB/T 41-2016 Hexagon nuts, style 1 - Product grade C (ISO 4034:2012, MOD)
GB/T 95 Plain washers - Product grade C (GB/T 95-2002, ISO 7091:2000, IDT)
GB/T 228.1 Metallic materials - Tensile testing - Part 1 : Method of test at room temperature (GB/T 228.1-2010, ISO 6892-1:2009, MOD)
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method (GB/T 231.1-2018, ISO 6506-1:2014, MOD)
GB/T 5780-2016 Hexagon head bolts - Product grade C (ISO 4016:2011, MOD)
GB/T 17219 Standard for safety evaluation of equipment and protective materials in drinking water system
GB/T 17241.6 Integral cast iron flanges
GB/T 17456.1 Ductile iron pipes - External zinc-based coating - Part 1: Metallic zinc with finishing layer (GB/T 17456.1-2009, ISO 8179-1:2004, IDT)
GB/T 17456.2 Ductile iron pipes - External zinc coating - Part 2: Zinc rich paint 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 Method of testing cements - Determination of strength (GB/T 17671-1999, idt ISO 679:1989)
GB/T 21873 Rubber seals - Joint rings for water supply drainage and sewerage pipelines - Specification for materials (GB/T 21873-2008, ISO 4633:2002, MOD)
GB/T 32488 Ductile iron pipes and fittings - Seal coats for cement mortar linings (GB/T 32488-2016, ISO 16132:2004, MOD)
GB/T 36173 Restrained joint systems for ductile iron pipelines - Design rules and type testing (GB/T 36173-2018, ISO 10804:2010, MOD)
YB/T 4564 Ductile iron pipes for trenchless applications (YB/T 4564-2016, ISO 13470:2012, MOD)
ISO 7005-2 Metallic flanges - Part 2: Cast iron flanges
ISO 9001 Quality management systems - Requirements
ISO 10803 Design method for ductile iron pipes
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 ductile iron
cast iron used for pipes, fittings and accessories in which graphite is present primarily in spheroidal form
3.2 pipe
casting of uniform bore, with straight axis, having either socket, spigot or flanged ends
Note: This does not apply to flanged sockets, flanged spigots and collars, which are classified as fittings.
3.3 fitting
ductile iron casting other than a pipe, which allows pipeline deviation, change of direction, branch, bore or joint type
Note: Flanged sockets, flanged spigots and collars are also classified as fittings.
3.4 accessory
any component other than a pipe or fitting, which is used in a pipeline
Example 1: Glands and bolts for mechanical flexible joints (see 3.14).
Example 2: Glands, bolts and locking rings or segments for restrained joints (see 3.16).
Note: The term "accessory" is not relevant for valves or hydrants of any type.
3.5 component
any product defined as a pipe, fitting or accessory in pipeline system (see 3.2, 3.3 and 3.4)
3.6 socket
female end of a pipe or fitting to make the connection with the spigot of the next component
3.7 spigot
male end of a pipe or fitting
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
4.1 General
4.2 Pressure and wall thickness classification and dimensional requirements
4.3 Material characteristics
4.4 Coating and linings for pipes
4.5 Marking
5 Leaktightness requirements
5.1 Pipes and fittings
5.2 Flexible joints
5.3 Flanged joints as cast, screwed, welded and adjustable
6 Test methods
6.1 Dimensions
6.2 Straightness of pipes
6.3 Tensile test
6.4 Brinell hardness
6.5 Works leaktightness test of pipes and fittings
6.6 Coating and lining
7 Type test
7.1 General
7.2 Leaktightness of joints to internal pressure
7.3 Leaktightness of joints to external pressure
7.4 Leaktightness of joints to negative internal pressure
7.5 Leaktightness of joints to cyclic pressure
7.6 Leaktightness and mechanical resistance of flanged joints
8 Works inspection and quality certificate
8.1 Inspection and acceptance
8.2 Batching rule
8.3 Sampling size
8.4 Quality certificate
9 Tables of dimensions
9.1 Socket and spigot pipes
9.2 Flanged pipes
9.3 Fittings for socketed joints
9.4 Fittings for flanged joints
Annex A (Informative) Comparison between clause numbers in this standard and those in ISO 2531:2009
Annex B (Informative) Technical differences between this standard and ISO 2531:2009 and their reasons
Annex C (Informative) Allowable pressure
Annex D (Informative) Dimensions of pressure class pipes
Annex E (Normative) Pipe wall thicknesses, diametral stiffness and diametral deflection
Annex F (Informative) External protection
Annex G (Informative) Internal protection
Annex H (Informative) Safety factors
Annex I (Normative) Quality assurance
Annex J (Informative) Condensate cylinder
Bibliography
