GB 50650-2011(2022) Code for design protection of petrochemical plant against lightning English
1 General Provisions
1.0.1 This code was formulated with view to preventing and reducing the equipment damages and personal injuries caused by lightning stroke and standardizing the lightning protection design of petrochemical plants and their support facilities.
1.0.2 This code is applicable to the lightning protection design of petrochemical plant and its support facilities for new, renovation and/or expansion projects using petroleum, natural gas, coal and its products as raw materials to produce fuels and chemical products, while it is not applicable to the lightning protection design of facilities for the extraction and long-distance transportation of crude oil or those for the petroleum product storage and marketing outside the plant area of petrochemical plant.
1.0.3 The lightning protection design of petrochemical plant shall not only comply with this code, but also shall comply with those specified in the current relevant standards of the nation.
2 Terms
2.0.1 Petrochemical plant
The production plant that produces petrochemical products (or intermediates) with petroleum, natural gas and their products as the raw materials.
2.0.2 Support facilities
The facilities that are necessary to cooperate with the main process plant to complete the production process, including tank field, central laboratory, wastewater treatment plant, maintenance room and torch, etc.
2.0.3 Industrial building (warehouse)
The productive (storing) building that is built with roof and with the external envelope structure wholly adopting closed wall (including doors and windows) structure.
2.0.4 Outdoor unit
The well-ventilated place that is in the open air or is open to the atmosphere.
2.0.5 Semi-enclosed industrial buildings
The productive building that is built with roof and with the external envelope structure partially adopting wall, of which the area does not exceed 1/2 of the surface area of the external envelope of this building (excluding the area of roof and floor).
2.0.6 Opened industrial buildings
The productive building that is built with roof but without external envelope structure.
2.0.7 Lightning stroke
One electric discharge during the stroke to the ground.
2.0.8 Direct lightning flash
The lightning stroke that directly attacks the building (structure), other objects, the ground or the external lightning protection system and also produces electrical effect, heat effect and mechanical force.
2.0.9 Lightning induction
Spark discharge between metal parts produced by the lightning electrostatic induction and lightning electromagnetic induction occurring on the conductor nearby at the time of lightning discharge
2.0.10 Lightning surge on incoming services
Due to the action of lightning to the overhead lines, cable lines or metal pipelines, the lightning wave, namely the lightning surge, may invade into room along these pipelines and thereby endanger the personal safety or damage the equipment.
2.0.11 Lightning protection system (LPS)
One integrated system that is used to decrease the physical damages caused by the lightning stroke on production plants and is composed of external lighting protection system and internal lighting protection system
2.0.12 External lightning protection system
One component part of the lighting protection system, which is composed of air-termination system, down-conductor system and earth-termination system.
2.0.13 Internal lightning protection system
One component part of the lighting protection system, which is composed of bonding network and the electrical insulation of the external lighting protection system.
2.0.14 Air-termination system
The component part of the external lighting protection system, which is composed of such metal members as air-termination rod (lightning rod), air-termination wire and air-termination network.
2.0.15 Down-conductor system
The component part of the external lighting protection system, which is used to lead the lightning current from the air-termination system to the earth-termination system.
2.0.16 Earth-termination system
The component part of external lighting protection system, which is used to conduct lightning current and also distribute the lightning current to the ground.
2.0.17 Earthing electrode
The conductor buried in soil or concrete foundation for the purpose of distributing current.
2.0.18 Earthing conductor
The bonding conductor from the breaking of contact or the conductor-changing place of the down-conductor system to the earthing electrode; or the bonding conductor from the earthing terminal or equipotential bonding bar to the earthing electrode or earth-termination system.
2.0.19 Bonding network
One system interconnecting all the conductive objects (excluding the live conductors) to the earth-termination system.
2.0.20 Earthing system
The overall system combining the earth-termination system and bonding network together.
2.0.21 Ground resistance
The real part of the impedance between a given point of the system, device or equipment and the reference ground at a given frequency.
2.0.22 Power frequency ground resistance
The resistance obtained by the power frequency alternating current flowing to the ground through earthing electrode.
2.0.23 Impulse ground resistance
The ground resistance obtained by the surge current flowing to the ground through earthing electrode (the ratio of the peak value of voltage to the peak value of current on the earthing electrode).
3 Classification of Lightning Protection Places
3.0.1 Various places of petrochemical plants shall be classified into industrial building or outdoor unit according to the environmental conditions that are able to form explosive gas mixtures and the dissipation condition of gas in the space.
3.0.2 The semi-enclosed and opened industrial buildings shall be classified into industrial building or outdoor unit according to their opening degree. The large-scale compressor plant building with roof and opened wall surface shall be classified as the industrial building; while the frame with equipment or pipes sparsely arranged shall be classified as outdoor unit.
4 Basic Requirements
4.1 Places of Industrial Building Category
4.1.1 The lightning protection design of the places of petrochemical plant industrial building category shall comply with the relevant requirements of the current national standard "Design Code for Protection of Structures against Lightning" (GB 50057).
4.1.2 The lightning protection design of the petrochemical plant outdoor unit shall comply with the relevant requirements of Chapter 5 in this code.
4.2 Places of Outdoor Unit
4.2.1 The outdoor unit of petrochemical plant shall be carried out with lightning protection design on meeting any one of the following conditions:
1 The large and tall production facilities set on the floor;
2 The production facilities set at high position by frame or support and the main pipelines led to torches, etc.;
3 Rotating equipment, like the large-scale compressor set on the floor and the pumps arranged in groups, etc.;
4 Torch, chimney and exhaust funnel in the open space;
5 The lighting facilities that are set at high position and are easy to be attacked by direct lightning flash.
4.2.2 The outdoor unit of petrochemical plant may not be subjected to protection design against direct lightning flash on meeting any one of the following conditions: but it shall be grounded reliably:
1 The water treatment places dispersedly arranged in the open space (excluding the import equipment);
2 A few pumps and small-scale metal equipment that is dispersedly arranged on the floor;
3 Ground pipelines and pipe supports.
4.2.3 The air-termination system against direct lightning flash should use the metal solid body of production facilities but shall meet the following requirements:
1 The production facility used as air-termination system shall be integrally enclosed metallic static equipment with welded structure; and the rotating equipment shall not be used as air-termination system;
1 General Provisions
2 Terms
3 Classification of Lightning Protection Places
4 Basic Requirements
4.1 Places of Industrial Building Category
4.2 Places of Outdoor Unit
4.3 Discharge Facilities of Outdoor Unit
4.4 Other Measures
5 Lightning Protection of Outdoor Systems
5.1 Furnace Area
5.2 Tower Area
5.3 Static Equipment Area
5.4 Machinery Equipment Area
5.5 Tank Area
5.6 Combustible Liquid Loading Depot
5.7 Powder and Aggregate Silo
5.8 Frame, Pipe Support and Pipeline
5.9 Cooling Tower
5.10 Chimney and Torch
5.11 Discharge Facilities of the Outdoor Unit
5.12 Outdoor Lamps and Electrical Equipments
6 Lightning Protection System (LPS)
6.1 Air-Termination System
6.2 Down-Conductor System
6.3 Earth-Termination System
Explanation of Wording in This Code
List of Quoted Standards
