Static bonding

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The function of static electricity bonding: Static electricity bonding is used to eliminate static electricity and prevent the generation of static sparks. It involves using metals with good electrical conductivity to connect two flanges or valve flanges together, thereby grounding the pipeline. Flanges are usually coated with anti-corrosion materials, which can lead to poor contact and the formation of sparks. Static electricity bonding is employed to prevent accidents by providing a pathway for the accumulated charge to be discharged. I. Where are static discharge bonds required? 1. \"Code for Design of Static Grounding in Chemical Enterprises\" (HG/T 20675-1990) 3.4.4 All containers used to hold flammable and explosive materials, such as barrels and bottles, should be placed on conductive flooring; such flooring must be free of insulating residues and connected to the grounding wire. The wheels of a cart with wheels should be made of a material with electrical conductivity. Weighing scales such as bench scales and floor scales used for measurement should be connected to the grounding main line via connection wires. Small containers should be connected to the grounding main using battery clamps and jumpers. 3.4.5 The belt of the belt conveyor should preferably be made of a conductive material. When the belt is insulating, metal materials should not be used for the belt joints. The belt cover must be grounded and securely fixed, with no contact or scraping with the belt. II. \"Code for Design of Static Grounding in Petrochemical Industries\" (SH/T 3097-2017) 4.1.1 During production, processing, storage, and transportation, equipment, pipelines, operating tools, as well as human bodies, may generate and accumulate static electricity, which can pose static electricity hazards; therefore, static grounding measures should be taken. 5.1.1 The enclosures of fixed equipment (towers, vessels, pumps, heat exchangers, filters, etc.) shall be electrically grounded to prevent static electricity. Earth covering equipment generally does not require static grounding. III. \"Code for Design of Oil Depots\" (GB 50074-2014) 14.3.8 For road tankers or drum filling facilities used for Class A, B, and C liquids, anti-static grounding devices that are connected to the tanks or drums shall be installed. 14.3.9 Loading and unloading docks for flammable and combustible liquids shall be equipped with anti-static grounding devices that connect to the ships. IV. Code for Fire Protection Design of Petrochemical Enterprises (GB 50160-2008) 9.3.1 Grounding measures shall be taken for all equipment and pipelines in areas at risk of explosion and fire that may generate static electricity. 9.3.2 An electrostatic grounding system shall be installed in the polyolefin resin treatment system, conveying system, and silo area; there shall be no isolated conductors that are not grounded. 9.3.5 Road tank trucks, railway tank cars, and loading/unloading platforms shall be equipped with dedicated static grounding wires. V. Code for Design of Boiler Rooms (GB 50041-2008) 15.2.17 Gas and liquid fuel pipelines shall be equipped with static electricity grounding devices. VI. Code for Design of Foam Fire Extinguishing Systems (GB 50151-2010) 3.7.10 Anti-static grounding measures shall be taken for dry pipes installed above ground or in trenches within explosion-proof areas. VII. \"Code for Design of Dry Powder Fire Extinguishing Systems\" (GB 50347-2004) 7.0.7 When the system pipes are installed in areas with explosion hazards, the metal components of the piping network shall be provided with anti-static grounding. 8. \"Code for Design of Oil and Gas Recovery Facilities in Oil Loading Systems\" (GB 50759-2012) 9.1.1 Static electricity grounding devices shall be installed on the oil pipelines, equipment, and enclosures within the oil and gas recovery facilities. 9. \"Code for Design of Producer Gas Stations\" (GB 50159-2013) 17.0.5 Coal gas pipelines shall be equipped with grounding devices for static electricity discharge. 10. \"Code for Design of Clean Rooms in the Pharmaceutical Industry\" (GB 50457-2008) 6.4.2 Pipelines for transporting flammable media. Grounding facilities for dissipating static electricity should be installed. 9.5.3 The cleanroom’s air handling system shall incorporate anti-static grounding measures. 11.4.3 The clean air handling system in medical cleanrooms (areas) shall incorporate anti-static grounding measures. 11. Code for Design of Dyeing and Printing Factories (GB 50426-2016) 8.4.6 The ventilation system used in rooms with explosion hazards shall have reliable anti-static grounding measures. 12. \"General Guidelines for Preventing Static Electricity Accidents\" (GB 12158-2006) 6.4.10 Equipment used for collecting and filtering powders shall employ anti-static containers and filter media, which must also be grounded. 13. \"Technical Specifications for Inert Gas Fire Extinguishing Systems\" (CECS 312:2012) 6.0.5 Pipeline systems that pass through areas with explosion hazards as well as substation and power distribution areas shall be provided with anti-static grounding. 14. \"Technical Specifications for Hydrogen Refueling Stations\" (GB 50516-2010) 10.3.4 Anti-static grounding devices shall be installed at the hydrogen refueling unit and in its vicinity. 15. \"Code for Design of Wastewater Treatment and Reuse in the Chemical Industry\" (GB 50684-2011) 5.3.10 The mechanical and electrical equipment in oil separation tanks should be equipped with explosion-proof measures, and anti-static grounding facilities shall be provided. 16. \"Code for Construction and Quality Acceptance of Anti-static Engineering\" (GB 50944-2013) 3.0.2 For new construction projects, anti-static grounding systems should be installed during the civil engineering construction phase. 17. Article 6.0.6 of the \"Code for Design of Gas Fire Extinguishing Systems\" (GB 50370-2005): Metal components such as pipelines and enclosures that pass through areas with explosion hazards as well as substations and power distribution rooms shall be equipped with anti-static grounding. 18. Article 80 of the “Regulations on Safety Inspection of Pressure Piping – Industrial Piping” (TSGD0001-2009) stipulates the following regarding anti-static bonding for flanges: For pipelines requiring static grounding, it is necessary to measure the resistance between each connecting joint as well as the resistance of the entire piping system to ground. 19. When the service pressure exceeds the requirements specified in the \"Code for Pressure Piping – Industrial Piping\" (GB/T20801-2006) or those outlined in the design documents, bypass wires (between flanges or threaded joints) and grounding leads shall be installed. As can be seen from this clause, to determine whether a bypass wire is needed for the flanges, it is necessary to measure the resistance between them; if the resistance value exceeds the specified limit, a bypass wire must be used. 20. Clause 10.12.1 of the \"Code for Pressure Piping – Industrial Piping, Part 4: Fabrication and Installation\" (GB/T20801.4-2006) stipulates that for pipelines requiring static grounding, good electrical conductivity must exist between various sections of such pipelines. When the resistance value between each pair of flanges or threaded joints is greater than 0.03Ω, a wire bridge should be installed. 21. Article 7.13.1 of the \"Code for Construction of Industrial Metal Piping Projects\" (GB 50235—2010) stipulates that for pipelines for which static electricity grounding is required, if the resistance value between each pair of flanges or other joints exceeds 0.03 ohms, a bonding wire should be installed. It can be seen that to determine whether metal flanges on industrial pipelines need to be bonded together, it is necessary to measure the resistance value between the flanges. When the resistance between the flanges exceeds 0.03Ω, a wire bridge should be installed. II. How should static grounding be done? The \"Technical Code for Static Grounding Design in Chemical Enterprises\" (HGJ28-90) has now been renumbered as HG/T20675-1990. Paragraph 2.7.5 of this specification states that when metal flanges are fastened using metal bolts or clamps, it is generally not necessary to install additional electrostatic connection wires. Under corrosive conditions, it is necessary to ensure that there are at least two contact surfaces between the bolts or clamps; rust and oil should be removed prior to installation, and anti-loosening nuts should be used during installation. The \"Explanations for the Preparation of Technical Specifications for Static Grounding Design in Chemical Enterprises\" provide the following explanation for clause 2.7.5: Based on the practical experience of many organizations, metal flanges connected by metal bolts possess sufficient static conductivity merely through the bolts themselves. The installation requirements under corrosive conditions are intended to ensure conductivity. The \"Code for Design of Static Grounding in Petrochemical Industries\" (SH3097-2000), as a corporate standard, is stricter than **national standards and industry standards. Paragraph 4.3.3 of this standard stipulates that in piping systems, when metal flanges are fastened using metal bolts or clamps, it is generally not necessary to install additional electrostatic connection wires; however, it is essential to ensure that there is good electrical contact between at least two bolts or clamps. Article 14.2.14 of the “Code for Design of Oil Depots” (GB 50074-2002) stipulates that bonding shall be applied at the flange connections of oil (oil-gas) pipelines. When connected by no less than 5 bolts, bypass wiring is not required in a non-corrosive environment. Article 10.3.3 of the \"Code for Design and Construction of Automobile Fueling and Gas Refueling Stations\" (GB 50156—2002) stipulates that in areas prone to explosion, metal wires should be used for bonding at connections such as flanges on oil, liquefied petroleum gas, and natural gas pipelines, as well as at both ends of rubber hoses. When there are no fewer than 5 connection bolts on the flange, bypass wiring is not required in non-corrosive environments. Article 6.12.2 of GB50235-97 \"Code for Construction and Acceptance of Industrial Metal Piping\" stipulates that when the earth resistance value of the piping system exceeds 100Ω, two grounding leads shall be provided. The grounding lead should be welded. SH3501-2002 \"Code for Construction and Acceptance of Toxic and Flammable Media in Petrochemical Industries\": Article 6.2.16 states that for stainless steel pipes requiring static electricity grounding, the wire bridging or grounding leads shall use stainless steel plates as a transition layer and must not be connected directly to the stainless steel pipe.