GB 5135.11-2025 Automatic sprinkler systems—Part 11: Grooved pipe couplings and fittings English, Anglais, Englisch, Inglés, えいご
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ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB 5135.11-2025
Replaces GB 5135.11-2003
Automatic sprinkler system - Part 11: Grooved pipe couplings and fittings
自动喷水灭火系统 第11部分：沟槽式管接件
Issue date: 2025-10-31 Implementation date: 2026-11-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
Introduction
1 Scope
2 Normative Reference Documents
3 Terms and Definitions
4 Classification and Model Designation
4.1 Classification
4.2 Model Designation
5. Requirements
5.1 Appearance and Marking
5.2 Product Specifications
5.3 Shell
5.4 Fasteners
5.5 Rubber Sealing Ring
5.6 Vacuum level (negative pressure sealing)
5.7 Air Tightness Performance
5.8 Sealing Performance
5.9 Pressure Resistance
5.10 Bearing Torque
5.11 Flex joint deflection angle
5.12 Elongation Clearance
5.13 Low-Temperature Resistance
5.14 High-Temperature Aging Resistance
5.15 Resistance to Water Impact
5.16 Vibration Resistance Performance
5.17 Fire Resistance
5.18 Equivalent Length
6. Test Methods
7 Inspection Rules
7.1 Inspection Classification and Items
7.2 Sampling Methods
7.3 Inspection Result Judgment
8. Markings and Instructions for Use
8.1 Logo
8.2 User Manual
9 Packaging, Transport, and Storage
Appendix A (Normative) Groove Dimensions
Appendix B (Normative) Maximum Permissible Diameter of Branch Pipes
Appendix C (Informative) Grooved Pipe Fitting Structural Lengths
1 Scope
This document defines the terms and definitions of grooved pipe couplings and fittings for automatic sprinkler systems, specifies the classification, model designation, requirements, inspection rules, marking, instructions for use, packaging, transportation, and storage requirements for grooved pipe couplings and fittings, and describes the corresponding test methods.
This document is applicable to the design, production, and inspection of grooved pipe couplings and fittings in automatic sprinkler systems.
2 Normative references
The provisions of the following documents, through reference in this text, constitute essential provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB/T 191 Packaging—Graphical symbols for handling of goods
GB/T 228.1 Metallic materials—Tensile testing—Part 1: Method of test at room temperature
GB/T 528 Vulcanized or thermoplastic rubbers—Determination of tensile stress-strain properties
GB/T 531 (all parts) Vulcanized or thermoplastic rubbers—Determination of indentation hardness
GB/T 1690 Vulcanized or thermoplastic rubbers—Determination of resistance to liquids
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 3098.1 Mechanical properties of fasteners—Bolts, screws, and studs
GB/T 3098.2 Mechanical properties of fasteners—Nuts
GB/T 3181 Standard colors for paint films
GB/T 3512 Vulcanized or thermoplastic rubbers—Accelerated aging and heat resistance tests
GB 5135.1 Automatic sprinkler systems—Part 1: Sprinklers
GB/T 7306 (all parts) 55° sealing pipe threads
GB/T 7759 (all parts) Vulcanized or thermoplastic rubbers—Determination of compression set
GB/T 9124.1 Steel pipe flanges—Part 1: PN series
GB/T 17241.1 Cast iron pipe flanges—Part 1: PN series
3 Terms and definitions
The following terms and definitions apply to this document.
3.1 Grooved pipe couplings and fittings
A general term for grooved pipe couplings and grooved pipe fittings.
3.2 Grooved pipe couplings
Assemblies used for quick connection of grooved pipes or fittings.
3.3 Grooved pipe fittings
A general term for fittings such as elbows, tees, crosses, reducers, and derived fittings in grooved pipe systems, with annular grooves machined at the ports to match the pipes.
3.4 Rigid (grooved) coupling joint
A split-type clamp assembly where adjacent pipe ends are not allowed to have relative angular displacement or axial displacement at the joint.
3.5 Flexible (grooved) coupling joint
A flexible split-type clamp assembly where adjacent pipe ends are allowed to have a certain amount of relative angular displacement and corresponding axial movement (the allowable angular displacement depends on the pipe diameter), but no axial linear displacement is permitted.
3.6 Gasket
A rubber ring that uses pressure to improve the sealing performance of the system, i.e., a rubber ring that enhances the sealing performance of the system by generating additional clamping force between the gasket and the sealing surface through applied pressure.
3.7 Rated working pressure
The maximum working pressure allowed for grooved pipe couplings and fittings under operating conditions.
4 Classification and model designation
4.1 Classification
Grooved pipe couplings and fittings are classified according to Table 1.
4.2 Model designation
The model designation method for grooved pipe couplings and fittings is as follows.
Note: For outlet specifications (including side outlets and reducing outlets), the groove-type is denoted by the outer diameter of the pipe (in millimeters), while the threaded type is denoted by the thread code and thread size. For other connection methods, the corresponding symbol and nominal diameter are used. When the outlet specifications match the main inlet specifications, the "×" and outlet specifications are omitted. For multiple outlets, different outlet specifications are separated by "×" and listed in order of main outlet and side outlet(s). If the specifications are identical, only one specification is listed.
Examples:
Example 1: A grooved pipe coupling with ductile iron housing, enterprise-defined code 1, inlet/outlet outer diameter of 165 mm, and rated working pressure of 1.6 MPa is denoted as XGQT1-165-1.6.
Example 2: A reducing grooved pipe coupling with ductile iron housing, enterprise-defined code 1G, inlet/outlet outer diameters of 168 mm and 165 mm, respectively, and rated working pressure of 1.6 MPa is denoted as XGQT1G-168×165-1.6.
Example 3: A straight grooved tee pipe fitting with stainless steel housing, enterprise-defined code 03, main inlet and all outlets with a 165 mm grooved connection, and rated working pressure of 2.5 MPa is denoted as XGSS03-165-2.5.
Example 4: A reducing grooved four-way pipe fitting with ductile iron housing, enterprise-defined code 04, main inlet/outlet with a 219 mm grooved connection, two side outlets with Rc3 threaded connections, and rated working pressure of 2.5 MPa is denoted as XGQT04-219×Rc3-2.5.
Example 5: A concentric grooved reducer pipe fitting with cast steel housing, enterprise-defined code 07, main inlet with a 219 mm grooved connection, reducing outlet with a 165 mm grooved connection, and rated working pressure of 2.5 MPa is denoted as XGZG07-219×165-2.5.
Example 6: A mechanical grooved four-way pipe fitting with ductile iron housing, enterprise-defined code 3S, main inlet/outlet with a 165 mm grooved connection, two side outlets with a 76 mm grooved connection and Rc1 threaded connection, respectively, and rated working pressure of 1.6 MPa is denoted as XGQT3S-165×76×Rc1-1.6.
