Issued by the State Administration for Market Regulation of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword i
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 Division and scope of area subject to grain dust explosion hazards 3
5 Process system and equipment requirements 4
5.1 Process design 4
5.2 Mechanical equipment 5
5.3 Grain drying system 8
6 Electrical requirements 9
6.1 General requirements 9
6.2 Selection of electrical equipment 10
6.3 Electrical lines 10
6.4 Lightning protection, electrostatic prevention and grounding 11
7 Building and structure 11
7.1 General requirements 11
7.2 Ground 12
7.3 Doors 12
8 Dust control requirements 12
8.1 Ventilation 12
8.2 Dust collection system 12
8.3 Dust accumulation 15
9 Dust cleaning requirements 15
10 Requirements for pneumatic conveying system 16
11 Requirements for explosion mitigation measures 16
11.1 General requirements 16
11.2 Explosion venting 16
11.3 Inerting 17
11.4 Explosion isolation 17
12 Requirements for operational safety management 18
12.1 General requirements 18
12.2 Production 19
13 Verification methods 20
Annex A (Informative) Examples of category and scope of area subject to grain dust explosion hazards 22
A.1 Examples of methods for zoning areas subject to grain dust explosion hazards according to building space 22
A.2 Examples of methods for zoning areas subject to grain dust explosion hazards according to the types and distance of source of dust release 24
Annex B (Informative) Selection of electrical equipment in areas subject to grain dust explosion hazards 26
Bibliography 28
Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB 17440-2008 Safety regulations for the protection of dust explosion for grain processing, storage and transportation system. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect to GB 17440-2008:
——The scope has been changed (see Clause 1 hereof; Clause 1 of Edition 2008);
——The terms and definitions of "hazardous area (dust)", "non-hazardous area (dust)", "Zone 20", "Zone 21" and "Zone 22" have been added (see 3.7, 3.8, 3.9, 3.10 and 3.11 hereof);
——The term and definition of “grain dust” have been deleted (see 3.6 of Edition 2008);
——The division and scope of area subject to grain dust explosion hazards have been changed (see Clause 4 hereof; Clause 4 of Edition 2008);
——Requirements for process design have been added (see 5.1.4, 5.1.5 and 5.1.6 hereof);
——Requirements for mechanical equipment have been changed (see 5.2 hereof; 5.2 of Edition 2008);
——Requirements for grain drying system have been added (see 5.3 hereof);
——Requirements for selection of electrical equipment, electrical lines, lightning protection, electrostatic prevention and grounding have been modified (see Clause 6 hereof; Clause 6 of Edition 2008);
——Safety requirements for the use of radiation equipment and ultrasonic equipment have been deleted (see Clauses 11 and 12, 6.2.3 and 6.2.4 of Edition 2008);
——Requirements for motor surface temperature control in the case of variable frequency adjustable speed have been added (see 6.2.5 hereof);
——Requirements for building and structure have been changed (see Clause 7 hereof; Clause 7 of Edition 2008);
——Requirements for dust control and requirements for push flow of dust collection system have been changed (see Clause 8 hereof; Clause 8 of Edition 2008);
——Requirements for dust cleaning have been changed (see Clause 9 hereof; Clause 9 of Edition 2008);
——Requirements for pneumatic conveying have been added (see 10.5 and 10.6 hereof);
——Measures and requirements for explosion mitigation, as well as the verification methods have been added (see Clauses 11 and 13 hereof);
——Requirements for operational safety management have been changed (see Clause 12 hereof; Clause 13 of Edition 2008);
Attention is drawn to the possibility that some content of this document may involve patents. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by and is under the jurisdiction of the Ministry of Emergency Management of the People's Republic of China.
The previous editions of this document and documents replaced by this document are as follows:
——This document was first issued as GB 17440-1998 in 1998 and first revised in 2008;
——This is the second revision.
Safety specification for the protection of dust explosion for grain processing, storage and transportation system
1 Scope
This document specifies the division and scope of area subject to grain dust explosion hazards in grain processing, storage and transportation system, process system and equipment requirements, electrical requirements, building and structure requirements, dust control requirements, dust cleaning requirements, pneumatic conveying requirements, requirements for explosion mitigation measures, and requirements for operational safety management, and describes the corresponding verification methods.
This document is applicable to the design, operation, and safety management of grain processing, storage and transportation system involving combustible dust explosion hazards.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB 12158 General requirements for preventing electrostatic accidents
GB 15577 Safety regulations for dust explosion prevention and protection
GB/T 15604 Terminology for dust explosion prevention and protection
GB/T 15605 Specifications for pressure venting of dust explosion
GB/T 37241 Guide on inerting for the prevention of explosions
GB 50016 Code for fire protection design of buildings
GB 50057 Code for design protection of structures against lightning
GB 50058 Code for design of electrical installations in explosive atmospheres
GB 55037 General code for fire protection of buildings and constructions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15604 and the following apply.
3.1
grain
general term for agricultural products for human consumption
Note: It mainly refers to wheat, corn, rice, soybeans, oil and other crops and their products in process, semi-finished products and finished products.
3.2
grain processing
process of converting unprocessed grain into finished or semi-finished grain through specific technology
3.3
grain storage and transportation
transportation and storage of grain, through grain circulation facilities and equipment, according to specific processes, methods and routes
3.4
source of dust release
locations or sites where combustible dust can be released into the atmospheric environment
Note: The source of dust release may come from dust collector or dust layer.
[Source: GB/T 3836.35-2021, 3.12]
3.5
explosive dust atmosphere
atmosphere that may keep combustion spreading freely after the mixture of combustible dust and gaseous oxidants (mainly air) is ignited under atmospheric conditions
[Source: GB 15577-2018, 3.2]
3.6
protection for grain dust explosion
techniques and measures to prevent the combustion and explosion of grain dust, and reduce the loss in the event of combustion and explosion of grain dust
3.7
hazardous area (dust)
area in which combustible dust, occurs or may occur in the form of a dust cloud in such quantities that special precautions are required for the construction, installation and use of equipment
Note 1: Hazardous areas are divided into zones based upon the frequency and duration of the occurrence of explosive dust atmospheres (see GB/T 3836.35-2021, 6.2).
Note 2: The potential hazard of creating an dust cloud from a dust layer also needs to be considered.
[Source: GB/T 3836.35-2021, 3.9]
3.8
non-hazardous area (dust)
area in which combustible dust may not occur in the form of a dust cloud in such quantities that special precautions are not required for the construction, installation and use of equipment
[Source: GB/T 3836.35-2021, 3.10]
3.9
Zone 20
place in which an explosive dust atmosphere, in the form of a dust cloud in air, is present continuously, or for long periods or frequently
[Source: GB/T 3836.35-2021, 3.25.1]
3.10
Zone 21
place in which an explosive dust atmosphere, in the form of a dust cloud in air, is likely to occur in normal operation
[Source: GB/T 3836.35-2021, 3.25.2]
3.11
Zone 22
area in which an explosive dust atmosphere, in the form of a dust cloud in air, is not likely to occur in normal operation but, if it does occur, will persist for a short period only
Note: The potential of creating an explosive dust cloud from a dust layer also needs to be considered.
[Source: GB/T 3836.35-2021, 3.25.3]
4 Division and scope of area subject to grain dust explosion hazards
4.1 The area subject to grain dust explosion hazards in grain processing, storage and transportation system shall be divided into Zone 20, Zone 21, and Zone 22 based on the frequency and duration of the occurrence of explosive grain dust atmosphere.
4.2 The division and scope of zoning of area subject to grain dust explosion hazards shall be determined based on conditions such as processes, material characteristics, location of source of grain dust release, quantity and possibility of dust release, explosion conditions, ventilation and dust collection, and structure and layout of the areas. Examples of zone division are given in Annex A.
4.3 When changes occur in processes, materials, structure and layout of areas, or operation organization methods, the enterprises shall re-evaluate, define and divide the scope and level of different zones in area subject to dust explosion hazards.
4.4 Throughout the duration of the entire operation, documentation on the division and description of zones shall be maintained, and the hazardous nature of the process and the zones shall be dynamically evaluated on a regular basis.
4.5 When changes occur in the zone classification and zone scope of area subject to grain dust explosion hazards, the enterprises shall take technical and management measures promptly to ensure that equipment and facilities within the changed area meet the protection requirements for grain dust explosion.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Division and scope of area subject to grain dust explosion hazards 5 Process system and equipment requirements 5.1 Process design 5.2 Mechanical equipment 5.3 Grain drying system 6 Electrical requirements 6.1 General requirements 6.2 Selection of electrical equipment 6.3 Electrical lines 6.4 Lightning protection, electrostatic prevention and grounding 7 Building and structure 7.1 General requirements 7.2 Ground 7.3 Doors 8 Dust control requirements 8.1 Ventilation 8.2 Dust collection system 8.3 Dust accumulation 9 Dust cleaning requirements 10 Requirements for pneumatic conveying system 11 Requirements for explosion mitigation measures 11.1 General requirements 11.2 Explosion venting 11.3 Inerting 11.4 Explosion isolation 12 Requirements for operational safety management 12.1 General requirements 12.2 Production 13 Verification methods Annex A (Informative) Examples of category and scope of area subject to grain dust explosion hazards A.1 Examples of methods for zoning areas subject to grain dust explosion hazards according to building space A.2 Examples of methods for zoning areas subject to grain dust explosion hazards according to the types and distance of source of dust release Annex B (Informative) Selection of electrical equipment in areas subject to grain dust explosion hazards Bibliography
ICS 13.230
CCS C 67
National Standard of the People’s Republic of China
GB 17440-2025
Replaces 17440-2008
Safety specification for the protection of dust explosion for grain processing, storage and transportation system
粮食加工、储运系统粉尘防爆安全规范
(English Translation)
Issue date: 2025-01-24 Implementation date: 2026-02-01
Issued by the State Administration for Market Regulation of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword i
1 Scope 1
2 Normative references 1
3 Terms and definitions 1
4 Division and scope of area subject to grain dust explosion hazards 3
5 Process system and equipment requirements 4
5.1 Process design 4
5.2 Mechanical equipment 5
5.3 Grain drying system 8
6 Electrical requirements 9
6.1 General requirements 9
6.2 Selection of electrical equipment 10
6.3 Electrical lines 10
6.4 Lightning protection, electrostatic prevention and grounding 11
7 Building and structure 11
7.1 General requirements 11
7.2 Ground 12
7.3 Doors 12
8 Dust control requirements 12
8.1 Ventilation 12
8.2 Dust collection system 12
8.3 Dust accumulation 15
9 Dust cleaning requirements 15
10 Requirements for pneumatic conveying system 16
11 Requirements for explosion mitigation measures 16
11.1 General requirements 16
11.2 Explosion venting 16
11.3 Inerting 17
11.4 Explosion isolation 17
12 Requirements for operational safety management 18
12.1 General requirements 18
12.2 Production 19
13 Verification methods 20
Annex A (Informative) Examples of category and scope of area subject to grain dust explosion hazards 22
A.1 Examples of methods for zoning areas subject to grain dust explosion hazards according to building space 22
A.2 Examples of methods for zoning areas subject to grain dust explosion hazards according to the types and distance of source of dust release 24
Annex B (Informative) Selection of electrical equipment in areas subject to grain dust explosion hazards 26
Bibliography 28
Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB 17440-2008 Safety regulations for the protection of dust explosion for grain processing, storage and transportation system. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect to GB 17440-2008:
——The scope has been changed (see Clause 1 hereof; Clause 1 of Edition 2008);
——The terms and definitions of "hazardous area (dust)", "non-hazardous area (dust)", "Zone 20", "Zone 21" and "Zone 22" have been added (see 3.7, 3.8, 3.9, 3.10 and 3.11 hereof);
——The term and definition of “grain dust” have been deleted (see 3.6 of Edition 2008);
——The division and scope of area subject to grain dust explosion hazards have been changed (see Clause 4 hereof; Clause 4 of Edition 2008);
——Requirements for process design have been added (see 5.1.4, 5.1.5 and 5.1.6 hereof);
——Requirements for mechanical equipment have been changed (see 5.2 hereof; 5.2 of Edition 2008);
——Requirements for grain drying system have been added (see 5.3 hereof);
——Requirements for selection of electrical equipment, electrical lines, lightning protection, electrostatic prevention and grounding have been modified (see Clause 6 hereof; Clause 6 of Edition 2008);
——Safety requirements for the use of radiation equipment and ultrasonic equipment have been deleted (see Clauses 11 and 12, 6.2.3 and 6.2.4 of Edition 2008);
——Requirements for motor surface temperature control in the case of variable frequency adjustable speed have been added (see 6.2.5 hereof);
——Requirements for building and structure have been changed (see Clause 7 hereof; Clause 7 of Edition 2008);
——Requirements for dust control and requirements for push flow of dust collection system have been changed (see Clause 8 hereof; Clause 8 of Edition 2008);
——Requirements for dust cleaning have been changed (see Clause 9 hereof; Clause 9 of Edition 2008);
——Requirements for pneumatic conveying have been added (see 10.5 and 10.6 hereof);
——Measures and requirements for explosion mitigation, as well as the verification methods have been added (see Clauses 11 and 13 hereof);
——Requirements for operational safety management have been changed (see Clause 12 hereof; Clause 13 of Edition 2008);
Attention is drawn to the possibility that some content of this document may involve patents. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by and is under the jurisdiction of the Ministry of Emergency Management of the People's Republic of China.
The previous editions of this document and documents replaced by this document are as follows:
——This document was first issued as GB 17440-1998 in 1998 and first revised in 2008;
——This is the second revision.
Safety specification for the protection of dust explosion for grain processing, storage and transportation system
1 Scope
This document specifies the division and scope of area subject to grain dust explosion hazards in grain processing, storage and transportation system, process system and equipment requirements, electrical requirements, building and structure requirements, dust control requirements, dust cleaning requirements, pneumatic conveying requirements, requirements for explosion mitigation measures, and requirements for operational safety management, and describes the corresponding verification methods.
This document is applicable to the design, operation, and safety management of grain processing, storage and transportation system involving combustible dust explosion hazards.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition (including any amendments) applies.
GB 12158 General requirements for preventing electrostatic accidents
GB 15577 Safety regulations for dust explosion prevention and protection
GB/T 15604 Terminology for dust explosion prevention and protection
GB/T 15605 Specifications for pressure venting of dust explosion
GB/T 37241 Guide on inerting for the prevention of explosions
GB 50016 Code for fire protection design of buildings
GB 50057 Code for design protection of structures against lightning
GB 50058 Code for design of electrical installations in explosive atmospheres
GB 55037 General code for fire protection of buildings and constructions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15604 and the following apply.
3.1
grain
general term for agricultural products for human consumption
Note: It mainly refers to wheat, corn, rice, soybeans, oil and other crops and their products in process, semi-finished products and finished products.
3.2
grain processing
process of converting unprocessed grain into finished or semi-finished grain through specific technology
3.3
grain storage and transportation
transportation and storage of grain, through grain circulation facilities and equipment, according to specific processes, methods and routes
3.4
source of dust release
locations or sites where combustible dust can be released into the atmospheric environment
Note: The source of dust release may come from dust collector or dust layer.
[Source: GB/T 3836.35-2021, 3.12]
3.5
explosive dust atmosphere
atmosphere that may keep combustion spreading freely after the mixture of combustible dust and gaseous oxidants (mainly air) is ignited under atmospheric conditions
[Source: GB 15577-2018, 3.2]
3.6
protection for grain dust explosion
techniques and measures to prevent the combustion and explosion of grain dust, and reduce the loss in the event of combustion and explosion of grain dust
3.7
hazardous area (dust)
area in which combustible dust, occurs or may occur in the form of a dust cloud in such quantities that special precautions are required for the construction, installation and use of equipment
Note 1: Hazardous areas are divided into zones based upon the frequency and duration of the occurrence of explosive dust atmospheres (see GB/T 3836.35-2021, 6.2).
Note 2: The potential hazard of creating an dust cloud from a dust layer also needs to be considered.
[Source: GB/T 3836.35-2021, 3.9]
3.8
non-hazardous area (dust)
area in which combustible dust may not occur in the form of a dust cloud in such quantities that special precautions are not required for the construction, installation and use of equipment
[Source: GB/T 3836.35-2021, 3.10]
3.9
Zone 20
place in which an explosive dust atmosphere, in the form of a dust cloud in air, is present continuously, or for long periods or frequently
[Source: GB/T 3836.35-2021, 3.25.1]
3.10
Zone 21
place in which an explosive dust atmosphere, in the form of a dust cloud in air, is likely to occur in normal operation
[Source: GB/T 3836.35-2021, 3.25.2]
3.11
Zone 22
area in which an explosive dust atmosphere, in the form of a dust cloud in air, is not likely to occur in normal operation but, if it does occur, will persist for a short period only
Note: The potential of creating an explosive dust cloud from a dust layer also needs to be considered.
[Source: GB/T 3836.35-2021, 3.25.3]
4 Division and scope of area subject to grain dust explosion hazards
4.1 The area subject to grain dust explosion hazards in grain processing, storage and transportation system shall be divided into Zone 20, Zone 21, and Zone 22 based on the frequency and duration of the occurrence of explosive grain dust atmosphere.
4.2 The division and scope of zoning of area subject to grain dust explosion hazards shall be determined based on conditions such as processes, material characteristics, location of source of grain dust release, quantity and possibility of dust release, explosion conditions, ventilation and dust collection, and structure and layout of the areas. Examples of zone division are given in Annex A.
4.3 When changes occur in processes, materials, structure and layout of areas, or operation organization methods, the enterprises shall re-evaluate, define and divide the scope and level of different zones in area subject to dust explosion hazards.
4.4 Throughout the duration of the entire operation, documentation on the division and description of zones shall be maintained, and the hazardous nature of the process and the zones shall be dynamically evaluated on a regular basis.
4.5 When changes occur in the zone classification and zone scope of area subject to grain dust explosion hazards, the enterprises shall take technical and management measures promptly to ensure that equipment and facilities within the changed area meet the protection requirements for grain dust explosion.
Contents of GB 17440-2025
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Division and scope of area subject to grain dust explosion hazards
5 Process system and equipment requirements
5.1 Process design
5.2 Mechanical equipment
5.3 Grain drying system
6 Electrical requirements
6.1 General requirements
6.2 Selection of electrical equipment
6.3 Electrical lines
6.4 Lightning protection, electrostatic prevention and grounding
7 Building and structure
7.1 General requirements
7.2 Ground
7.3 Doors
8 Dust control requirements
8.1 Ventilation
8.2 Dust collection system
8.3 Dust accumulation
9 Dust cleaning requirements
10 Requirements for pneumatic conveying system
11 Requirements for explosion mitigation measures
11.1 General requirements
11.2 Explosion venting
11.3 Inerting
11.4 Explosion isolation
12 Requirements for operational safety management
12.1 General requirements
12.2 Production
13 Verification methods
Annex A (Informative) Examples of category and scope of area subject to grain dust explosion hazards
A.1 Examples of methods for zoning areas subject to grain dust explosion hazards according to building space
A.2 Examples of methods for zoning areas subject to grain dust explosion hazards according to the types and distance of source of dust release
Annex B (Informative) Selection of electrical equipment in areas subject to grain dust explosion hazards
Bibliography
