GB 5135.3-2025 Automatic sprinkler system—Part 3:Water spray nozzle English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB 5135.3-2025
Replaces GB 5135.3-2003
Automatic sprinkler system - Part 3: Water spray nozzle
自动喷水灭火系统 第3部分:水雾喷头
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 References
3 Terms and Definitions
4 Classification and Model Designation
4.1 Classification
4.2 Model Designation
5 Requirements
5.1 General Requirements
5.2 Appearance and Marking
5.3 Connection Threads
5.4 Flow Coefficient
5.5 Spray Angle
5.6 Water Distribution Performance
5.7 Droplet Size
5.8 Spraying Performance
5.9 Nozzle Strength
5.10 Stress Corrosion Resistance
5.11 Resistance to Sulfur Dioxide/Carbon Dioxide Corrosion
5.12 Salt Spray Corrosion Resistance
5.13 Low Temperature Resistance
5.14 High Temperature Resistance
5.15 Vibration Resistance
5.16 Mechanical Impact Resistance
5.17 Dust Cap Performance
5.18 Closed-type Waterspray Nozzles
6 Test Methods
7 Inspection Rules
7.1 Inspection Categories and Items
7.2 Sampling Methods
7.3 Inspection Result Judgment
8 Instruction Manual
9 Packaging, Transportation, and Storage
Appendix A (Normative) Tolerances
Appendix B (Informative) Spray Patterns
1 Scope
This document defines the terms and definitions for waterspray nozzles in automatic sprinkler systems, and specifies the classification, model designation, requirements, inspection rules, instruction manuals, and packaging, transport, and storage requirements. It also describes corresponding test methods.
This document applies to the design, manufacture, and inspection of waterspray nozzles in automatic sprinkler systems.
2 Normative References
The contents of the following documents, through normative reference in this text, constitute essential provisions of this document. For dated references, only the edition cited applies; for undated references, the latest version (including all amendments) applies.
GB 5135.1 Automatic sprinkler systems – Part 1: Sprinklers
GB/T 7306.2 55° Sealing Pipe Threads – Part 2: Taper Internal Threads and Taper External Threads
GB/T 9969 General Principles for Instruction Manuals of Industrial Products
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1 Waterspray nozzle
A nozzle that atomizes water flow into droplets with a diameter of less than 1 mm and projects them in a designed spray pattern under certain pressure conditions.
3.2 Spray angle
The apex angle of the cone formed by the water mist expanding around the nozzle axis.
3.3 Centrifugal spray
The process where pressurized water flow enters the nozzle and, under the action of centrifugal components, forms fine mist droplets.
3.4 Impact spray
The process where pressurized water flow impacts a splash disc or a spiral cone to produce fine droplets.
3.5 Effective range
The horizontal distance between the highest point reached by the water mist and the plane perpendicular to the nozzle axis where the nozzle orifice is located.
3.6 Horizontal spray maximal height
The vertical distance from the highest point reached by the water mist to the nozzle axis during horizontal spraying.
3.7 Characteristic diameter of droplet volume percentage
Designated as DV0.90. The diameter below which 90% of the total volume of the spray liquid consists of droplets of this size or smaller.
4 Classification and Model Designation
4.1 Classification
4.1.1 Classification by atomization method
4.1.1.1 Type A waterspray nozzle: Centrifugal atomization nozzle with a specific angle between the inlet and outlet.
4.1.1.2 Type B waterspray nozzle: Centrifugal atomization nozzle with the inlet and outlet on a straight line.
4.1.1.3 Type C waterspray nozzle: Impact atomization nozzle where water flow strikes a splash disc or spiral cone.
4.1.2 Classification by presence of release assembly
4.1.2.1 Open-type waterspray nozzle: Waterspray nozzle without a release assembly.
4.1.2.2 Closed-type waterspray nozzle: Waterspray nozzle equipped with a release assembly.
4.2 Model Designation
The model designation for waterspray nozzles shall comply with the following rules:
Note: The custom code, specified by the manufacturer to indicate material or other product information, shall consist of uppercase English letters and contain no more than 3 characters.
Example 1: ZSTW A 40/120 indicates a Type A open-type waterspray nozzle with a nominal K-factor of 40 and a spray angle of 120°.
Example 2: ZSTW B 30/150/68℃ indicates a Type B closed-type waterspray nozzle with a nominal K-factor of 30, a spray angle of 150°, and a nominal operating temperature of 68°C.
5 Requirements
5.1 General Requirements
5.1.1 Waterspray nozzles shall be designed and manufactured such that they cannot be adjusted, disassembled, or reassembled.
5.1.2 Centrifugal atomization nozzles shall be equipped with a filter or screen at the inlet. The maximum pore size shall not exceed 80% of the minimum flow path diameter.
5.1.3 The seal at the outlet of closed-type waterspray nozzles shall not use rubber sealing elements.
5.1.4 The deviation between the measured mass of each waterspray nozzle and the manufacturer's declared mass shall not exceed 5% of the declared value.
5.2 Appearance and Marking
5.2.1 Waterspray nozzles shall be free from processing defects and mechanical damage, with uniform and complete surface coating/plating, and free from obvious impact marks or deformation.
5.2.2 Waterspray nozzles shall have permanent marking applied in a prominent location, which shall include at least the model designation, manufacturer's code or trademark, and year of production. All marks shall be correct, clear, and durable.
5.3 Connection Threads
The connection threads of waterspray nozzles shall comply with the requirements of GB/T 7306.2.
5.4 Flow Coefficient
When tested according to the method specified in 6.2, no pressure oscillation shall occur during pressurization and depressurization. The deviation between the flow coefficient at each pressure point and the nominal value shall not exceed ±5% of the nominal value.
5.5 Spray Angle
When tested according to the method specified in 6.3:
If the spray angle is less than 100°, the allowable deviation shall be ±5°.
If the spray angle is 100° or greater, the allowable deviation shall be ±10°.
Note: Common spray angle specifications include five grades: 45°, 60°, 90°, 120°, and 150°.
GB 5135.3-2025 Automatic sprinkler system—Part 3:Water spray nozzle English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB 5135.3-2025
Replaces GB 5135.3-2003
Automatic sprinkler system - Part 3: Water spray nozzle
自动喷水灭火系统 第3部分:水雾喷头
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 References
3 Terms and Definitions
4 Classification and Model Designation
4.1 Classification
4.2 Model Designation
5 Requirements
5.1 General Requirements
5.2 Appearance and Marking
5.3 Connection Threads
5.4 Flow Coefficient
5.5 Spray Angle
5.6 Water Distribution Performance
5.7 Droplet Size
5.8 Spraying Performance
5.9 Nozzle Strength
5.10 Stress Corrosion Resistance
5.11 Resistance to Sulfur Dioxide/Carbon Dioxide Corrosion
5.12 Salt Spray Corrosion Resistance
5.13 Low Temperature Resistance
5.14 High Temperature Resistance
5.15 Vibration Resistance
5.16 Mechanical Impact Resistance
5.17 Dust Cap Performance
5.18 Closed-type Waterspray Nozzles
6 Test Methods
7 Inspection Rules
7.1 Inspection Categories and Items
7.2 Sampling Methods
7.3 Inspection Result Judgment
8 Instruction Manual
9 Packaging, Transportation, and Storage
Appendix A (Normative) Tolerances
Appendix B (Informative) Spray Patterns
1 Scope
This document defines the terms and definitions for waterspray nozzles in automatic sprinkler systems, and specifies the classification, model designation, requirements, inspection rules, instruction manuals, and packaging, transport, and storage requirements. It also describes corresponding test methods.
This document applies to the design, manufacture, and inspection of waterspray nozzles in automatic sprinkler systems.
2 Normative References
The contents of the following documents, through normative reference in this text, constitute essential provisions of this document. For dated references, only the edition cited applies; for undated references, the latest version (including all amendments) applies.
GB 5135.1 Automatic sprinkler systems – Part 1: Sprinklers
GB/T 7306.2 55° Sealing Pipe Threads – Part 2: Taper Internal Threads and Taper External Threads
GB/T 9969 General Principles for Instruction Manuals of Industrial Products
3 Terms and Definitions
The following terms and definitions apply to this document.
3.1 Waterspray nozzle
A nozzle that atomizes water flow into droplets with a diameter of less than 1 mm and projects them in a designed spray pattern under certain pressure conditions.
3.2 Spray angle
The apex angle of the cone formed by the water mist expanding around the nozzle axis.
3.3 Centrifugal spray
The process where pressurized water flow enters the nozzle and, under the action of centrifugal components, forms fine mist droplets.
3.4 Impact spray
The process where pressurized water flow impacts a splash disc or a spiral cone to produce fine droplets.
3.5 Effective range
The horizontal distance between the highest point reached by the water mist and the plane perpendicular to the nozzle axis where the nozzle orifice is located.
3.6 Horizontal spray maximal height
The vertical distance from the highest point reached by the water mist to the nozzle axis during horizontal spraying.
3.7 Characteristic diameter of droplet volume percentage
Designated as DV0.90. The diameter below which 90% of the total volume of the spray liquid consists of droplets of this size or smaller.
4 Classification and Model Designation
4.1 Classification
4.1.1 Classification by atomization method
4.1.1.1 Type A waterspray nozzle: Centrifugal atomization nozzle with a specific angle between the inlet and outlet.
4.1.1.2 Type B waterspray nozzle: Centrifugal atomization nozzle with the inlet and outlet on a straight line.
4.1.1.3 Type C waterspray nozzle: Impact atomization nozzle where water flow strikes a splash disc or spiral cone.
4.1.2 Classification by presence of release assembly
4.1.2.1 Open-type waterspray nozzle: Waterspray nozzle without a release assembly.
4.1.2.2 Closed-type waterspray nozzle: Waterspray nozzle equipped with a release assembly.
4.2 Model Designation
The model designation for waterspray nozzles shall comply with the following rules:
Note: The custom code, specified by the manufacturer to indicate material or other product information, shall consist of uppercase English letters and contain no more than 3 characters.
Example 1: ZSTW A 40/120 indicates a Type A open-type waterspray nozzle with a nominal K-factor of 40 and a spray angle of 120°.
Example 2: ZSTW B 30/150/68℃ indicates a Type B closed-type waterspray nozzle with a nominal K-factor of 30, a spray angle of 150°, and a nominal operating temperature of 68°C.
5 Requirements
5.1 General Requirements
5.1.1 Waterspray nozzles shall be designed and manufactured such that they cannot be adjusted, disassembled, or reassembled.
5.1.2 Centrifugal atomization nozzles shall be equipped with a filter or screen at the inlet. The maximum pore size shall not exceed 80% of the minimum flow path diameter.
5.1.3 The seal at the outlet of closed-type waterspray nozzles shall not use rubber sealing elements.
5.1.4 The deviation between the measured mass of each waterspray nozzle and the manufacturer's declared mass shall not exceed 5% of the declared value.
5.2 Appearance and Marking
5.2.1 Waterspray nozzles shall be free from processing defects and mechanical damage, with uniform and complete surface coating/plating, and free from obvious impact marks or deformation.
5.2.2 Waterspray nozzles shall have permanent marking applied in a prominent location, which shall include at least the model designation, manufacturer's code or trademark, and year of production. All marks shall be correct, clear, and durable.
5.3 Connection Threads
The connection threads of waterspray nozzles shall comply with the requirements of GB/T 7306.2.
5.4 Flow Coefficient
When tested according to the method specified in 6.2, no pressure oscillation shall occur during pressurization and depressurization. The deviation between the flow coefficient at each pressure point and the nominal value shall not exceed ±5% of the nominal value.
5.5 Spray Angle
When tested according to the method specified in 6.3:
If the spray angle is less than 100°, the allowable deviation shall be ±5°.
If the spray angle is 100° or greater, the allowable deviation shall be ±10°.
Note: Common spray angle specifications include five grades: 45°, 60°, 90°, 120°, and 150°.
