The function of electrostatic 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; it also provides a pathway for discharging the generated charge through equipment grounding or segmented grounding of the pipe racks. Where are static discharge bonds required? 1. \"Code for Design of Static Grounding in Chemical Enterprises\" (HG/T 20675-1990) 3.4.4 Various 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 must be connected to the grounding wire. A trolley with wheels should have wheels 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. 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) (2018 edition) 9.3.1 Grounding measures shall be taken for all equipment and pipelines in areas prone to explosion and fire hazards 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 tankers, 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 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 For the clean air conditioning systems in pharmaceutical clean rooms (areas), anti-static grounding measures shall be taken. 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 Code for Inert Gas Fire Extinguishing Systems\" (CECS 312:2012) 6.0.5 Pipeline systems that pass through areas with explosion hazards as well as substations 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 should also 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 Technical Inspection of Pressure Pipelines – Industrial Pipelines\" (TSGD0001–2009) specifies the following regarding anti-static measures using flange connections: For pipelines that require static electricity grounding, it is necessary to measure the resistance values between each connection point as well as the resistance value of the pipeline system relative to the ground. 19. When the service pressure exceeds the requirements specified in the \"Code for Pressure Piping – Industrial Piping\" (GB/T20801-2006) or those in the design documents, bypass wires (between flanges or threaded connections) 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. 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. Section 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 lock nuts should be used during installation. The \"Explanations for the Compilation 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 simply through the connection of those bolts. The installation requirements under corrosive conditions are intended to ensure conductivity. The \"Code for Design of Static Grounding in Petrochemical Industries\" (SH3097-2017), as a corporate standard, is stricter than **national standards and industry standards. Section 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 50074-2014) stipulates that flange connections of oil (oil and gas) pipelines shall be bridged. When connected by no less than 5 bolts, bypass wiring is not required in non-corrosive environments. Article 10.3.3 of the “Code for Design and Construction of Motor Vehicle Gasoline and Gas Stations” (GB 50156—2002) stipulates that at joints such as flanges and both ends of rubber hoses on pipelines carrying oil products, liquefied petroleum gas, and natural gas within explosive hazard areas, metal wires shall be used for bonding. When there are no less than 5 connection bolts on the flange, bypass wiring is not required in a non-corrosive environment. Article 6.12.2 of GB50235-2010 “Code for Construction and Acceptance of Industrial Metal Piping” stipulates that when the resistance of a piping system to the ground exceeds 100 Ω, two grounding leads shall be provided. The grounding lead should be welded. SH3501-2011 \"Code for Construction and Acceptance of Toxic and Flammable Media in Petrochemical Industries\": Article 6.2.16 stipulates that for stainless steel pipes requiring static electricity grounding, the wiring connections or grounding leads must use stainless steel plates as a transition element; they shall not be connected directly to the stainless steel pipe. What exactly is ESD? ESD (Electro-Static discharge) means “electrostatic release”. ESD is a discipline that has developed since the mid-20th century, focusing on the study of the generation of static electricity, its hazards, and methods for its prevention. Therefore, internationally, equipment used for electrostatic protection is commonly referred to as ESD. The generation of static electricity: Static electricity is a natural phenomenon that exists objectively, and it can be generated in various ways, such as through contact, friction, or induction between electrical devices. The characteristics of static electricity include long-term accumulation, high voltage, low charge amount, small current, and a short duration of action. Factors such as the body’s own movements or contact, separation, friction, or induction with other objects can generate static electricity of several thousand volts or even tens of thousands of volts. Static electricity causes serious harm in various fields. Triboelectric charging and human static electricity are two major hazards in the electronics industry, often causing unstable operation of electronic and electrical products or even damaging them. The main measures for static electricity protection during the production process are static electricity leakage, dissipation, neutralization, humidification, shielding, and grounding. The human body static control system mainly consists of anti-static wrist straps, ankle straps, heel straps, workwear, shoes and socks, hats, gloves or finger cots, etc., and serves functions such as static discharge, neutralization, and shielding. Electrostatic protection is a long-term systematic effort; any mistake or oversight at any stage can lead to the failure of this protection effort. The hazards of static electricity: Static electricity is practically everywhere in our daily lives. Our bodies and the surroundings we’re in are exposed to very high levels of static voltage—thousands or even tens of thousands of volts. It might not be apparent in everyday life, but walking on a fiber-optic carpet can generate an electrostatic charge of around 35,000 volts, while flipping through plastic manuals can result in about 7,000 volts. For some sensitive instruments, such voltages can be deadly. Electrostatics primarily studies the applications of static electricity, such as electrostatic dust removal, electrostatic copying, and electrostatic biological effects. More importantly, there is the need for electrostatic protection technologies. In industries such as the electronics industry, petroleum industry, arms industry, textile industry, rubber industry, as well as in the aerospace and **fields, efforts are being made to mitigate losses caused by static electricity. With the rapid development of science and technology, the widespread application of microelectronics, and the increasing complexity of electromagnetic environments, the electromagnetic effects of electrostatic discharge, such as electromagnetic interference (EMI) and electromagnetic compatibility (EMC) issues, have become problems that need to be addressed urgently. On the one hand, the widespread use of products made from certain polymers with very high electrical resistivity, such as plastics and rubbers, as well as the increasing speed of modern production processes. On July 29, 1967, a serious accident occurred on the U.S. aircraft carrier Forrestal. A missile on an A4 aircraft suddenly ignited, resulting in $72 million in damages and injuring 134 people. The investigation revealed that the missile’s shielding connectors were defective, and static electricity caused the ignition. At the end of 1969, in less than a month, explosions occurred successively due to static electricity generated during the tank cleaning of three 200,000-ton supertankers from the Netherlands, Norway, and the United Kingdom. Industry challenges: The damage and harm caused by ESD (electrostatic discharge) to electronic products can be of two types – sudden damage and latent damage. Sudden damage refers to the severe deterioration of a device, resulting in the loss of its functionality. Such defects can usually be detected during quality checks in the production process; therefore, the main cost incurred for the factory is the expense associated with rework and repairs. Latent damage refers to situations where certain parts of the device are damaged but its functionality remains intact. Such damage cannot be detected during production inspections; however, it can render the product unstable during use, causing it to perform intermittently. Consequently, it poses an even greater threat to the overall product quality. Of these two types of failures, latent failures account for 90%, while sudden failures account for only 10%. In other words, 90% of static electricity-related damage cannot be detected; it is only discovered when the product is used by the end user. The majority of problems associated with mobile phones, such as frequent crashes, automatic shutdowns, poor voice quality, excessive noise, intermittent signal strength, and faulty button functions, are related to static electricity damage. For this reason as well, electrostatic discharge is considered the biggest potential threat to the quality of electronic products, and electrostatic protection has become an important aspect of quality control for such products. The difference in stability when using brand-name smartphones at home and abroad essentially reflects the differences in their electrostatic protection measures and the anti-electrostatic design of their products. Static electricity protection refers to the preventive measures taken to avoid electric shocks to people, fires and explosions caused by static electricity accumulation, as well as the failure and damage of electronic devices and the adverse effects on production. Its prevention principles mainly involve suppressing the generation of static electricity, accelerating its dissipation, and neutralizing it. When people wear non-conductive shoes, activities such as walking generate and accumulate charge, which can reach voltages in the kilovolt range. The highest potential generated by walking on a blanket, removing clothes, etc., can reach 2450 volts. At this time, when a person touches other objects, spark discharge occurs and they can suffer an electric shock. What are the main anti-static measures in human activities? Wearing conductive shoes ； Work clothes and undergarments should not be made of synthetic fabrics ； Wear anti-static work clothes containing conductive fibers or treated with antistatic agents ； The working surface is treated to make it conductive, etc. When two different objects come into contact, charge movement occurs at their interface, and positive and negative charges arrange themselves relative to each other to form a double layer. If the object is separated, equal amounts of charge with opposite polarities will be generated on each of the two objects. Anti-static principle: Try to eliminate the main factors that cause static electricity (such as the properties of the object, surface condition, history of charging, contact area and pressure, separation speed, etc.) ； Ensure that the objects in contact are as close as possible to each other in the charging sequence ； It is necessary to keep the contact area and pressure between objects low, the temperature low, the number of contacts low, the separation speed low, and to avoid sudden changes in the contact condition. Powders, liquids, and gases generate static electricity due to friction during transportation. Therefore, it is necessary to limit the flow rate and reduce pipe bends. Measures such as increasing the diameter and avoiding vibration.