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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 8856-2001 Dissolved acetylene systems, with respect to which, the following main technical changes have been made:
-- the normative references are updated;
-- the terms and definitions are modified;
-- the requirements of acetylene water content are modified;
-- the structural type provisions of acetylene generator are modified;
-- the requirements of high-pressure acetylene equipment are modified;
-- the provisions for medium-pressure pipelines are modified;
-- the material selection provisions for high-pressure pipelines are modified;
-- the performance requirements and performance test requirements of back-fire relief valves are modified.
This standard was proposed by the China Machinery Industry Federation.
This standard is under the jurisdiction of the National Technical Committee on Gas Separation and Liquefaction Equipment of Standardization Administration of China (SAC/TC 504).
The previous edition of this standard are as follows:
——ZB J76 020-1990;
——ZB J76 021-1990;
——JB/T 8856.1-1999;
——JB/T 8856. 2-1999;
——JB/T 8856-2001.
Dissolved acetylene systems
1 Scope
This standard specifies the terms and definitions, product classification, technical requirements, test methods, and inspection rules, as well as marking, packaging, transportation and storage of dissolved acetylene systems.
This standard is applicable to the system for producing dissolved acetylene with calcium carbide as raw material and with an output greater than or equal to 20 m3/h. Acetylene system for pipeline transportation of acetylene can be implemented by reference.
This standard does not apply to dedicated acetylene system for national defense, railway and shipping systems.
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 of the referenced document (including any amendments) applies.
GB/T 150 (All parts) Pressure Vessels
GB/T 567 (All parts) Bursting Disc Safety Devices
GB/T 4980 Determination of Noise Emitting by Displacement Compressor
GB/T 6479 Seamless Steel Tubes for High-Pressure for Chemical Fertilizer Equipment
GB 6819 Dissolved Acetylene
GB/T 7899 Gas Cylinder Regulator for Welding Segmentation and Similar Processes
GB/T 9948 Seamless Steel Tubes for Petroleum Cracking
GB/T 13306 Plates
GB/T 13384 General Specifications for Packing of Mechanical and Electrical Product
GB 50016 Code for Fire Protection Design of Buildings
GB 50058 Code for Design of Electrical Installations in Explosive Atmospheres
GB 50235 Code for Construction of Industrial Metallic Piping Engineering
HG/T 20517 Steel Low-Pressure Water-Sealed Gasholder
JB/T 9103 Reciprocating Piston Acetylene Compressor
NB/T 47003.1 Steel Welded Atmospheric Pressure Vessels
NB/T 4701 3.2 Nondestructive Testing of Pressure Equipment—Part 2: Radiographic Testing
TSG R0006 Safety Technical Supervision Regulation of Gas Cylinder
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
yield
under normal operating conditions, including loading and deslagging time, the average acetylene yield per hour of an acetylene generator within a working cycle not less than 8 h
3.2
deflagration
after decomposition or combustion of acetylene, the flame formed propagates to the unreacted gas side at a speed lower than the sound speed
Note: The pressure produced by acetylene deflagration can reach 9 ~ 11 times of the initial pressure.
3.3
detonation
the flame formed during decomposition or combustion of acetylene continues to propagate to the unreacted gas side at a speed higher than the sound speed (sometimes several times the sound speed)
Note: The pressure after detonation can be dozens of times or more than the initial pressure.
3.4
maximum allowable pressure
after considering the factors of acetylene deflagration, the maximum pressure (strength test pressure) that the system can withstand specified in the design of dissolved acetylene system
3.5
maximum allowable operating pressure
maximum allowable pressure of dissolved acetylene system during normal operation
3.6
piping
acetylene piping connected inside each unit of dissolved acetylene systems
Note: Acetylene piping includes blow off pipe, safety discharge pipe and cooling pipe of system, excluding acetylene piping connected between system and plant room.
3.7
design working life
when designing dissolved acetylene system, the working life shall be determined according to the corrosion rate of medium to materials and relevant factors
4 Pressure grading and product classification
4.1 Pressure grading
The operating pressure of each system in the dissolved acetylene systems is divided into three grades:
-- Low pressure: less than or equal to 0.02 MPa;
-- Medium pressure: greater than 0.02 MPa and less than or equal to 0.15 MPa;
-- High pressure: greater than 0.15 MPa and less than or equal to 2.5 MPa.
4.2 Product classification
Dissolved acetylene systems can be divided into two types (low pressure and medium pressure) according to different maximum allowable operating pressures of acetylene generator:
-- Low pressure dissolved acetylene systems: the maximum allowable operating pressure of acetylene generator is 0.02 MPa;
-- Medium pressure dissolved acetylene systems: the operating pressure of acetylene generator is greater than 0.02 MPa, and the maximum allowable operating pressure is 0.15 MPa.
5 Technical requirements
5.1 Performance indexes
The performance index of acetylene dissolving system shall be as specified in Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Pressure grading and product classification
4.1 Pressure grading
4.2 Product classification
5 Technical requirements
5.1 Performance indexes
5.2 Design calculation pressure
5.3 Allowable stress
5.4 Material
5.5 Structure
5.6 Piping and its accessories
5.7 Safety device
5.7 Safety valve
5.8 Design working life
5.9 Environmental (plant) requirements
5.10 Manufacture
5.11 Pressure test and air tightness test
5.12 Other requirements
6 Test methods
6.1 Classification of test
6.2 Complete equipment performance test
6.3 Test of single equipment and accessories before leaving the plant
7 Inspection rules
7.1 Inspection classification and items
7.2 Batching, sampling and judgment
8 Marking, packaging, transportation and storage
Annex A (Normative) Measuring water content of acetylene (gravimetric method)
A.1 Method principle
A.2 Apparatus, reagents and materials
A.3 Methods of determination