How do I determine whether a pipeline needs static grounding?

This post was last edited by xlxuiin on 2016-11-23 at 16:02. Discussion on anti-static bonding for metal pipe flanges: During safety inspections in enterprises, experts or law enforcement officers often require that metal pipe flanges used for transporting flammable and explosive substances be bonded together with wires to prevent static electricity-related accidents. So, are metal pipe flanges required to be bonded? Under what circumstances is it necessary to make a cross connection? The author would like to discuss this issue – flange static connection plates, flange static jumpers. I. Metal flange bridging for industrial pipelines: The Technical Code for Safety of Special Equipment, \"Regulations on the Safety Inspection of Pressure Pipelines – Industrial Pipelines\" (TSG D0001‑2009), issued by the General Administration of Quality Supervision, Inspection and Quarantine on May 8, 2009, provides the following definition for industrial pipelines: These regulations apply to industrial pipelines that are part of process units, auxiliary units, as well as utility systems within a facility, provided that they meet all of the following conditions: (1) The maximum operating pressure is greater than or equal to 0.1 MPa (gauge pressure, the same below) ； (2) Those with a nominal diameter (Note 1) greater than 25 mm ； (3) When the medium being transported is a gas, steam, liquefied gas, a liquid with a maximum operating temperature equal to or higher than its standard boiling point, or a liquid that is flammable, explosive, toxic, or corrosive. Most pressure pipes encountered during routine inspections fall under the category of industrial pipes mentioned above. Article 80 of the \"Regulations on Safety Inspection of Pressure Piping – Industrial Piping\" (TSG D0001–2009) 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 joint as well as the resistance value of the piping system relative to the ground. When the operating 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 connections) and grounding leads must 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. 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. In addition, Article 7.13.1 of the \"Code for Construction of Industrial Metal Piping Projects\" (GB 50235—2010) stipulates that for pipelines requiring static grounding, a conductive bridge should be installed when the resistance value between each pair of flanges or other joints exceeds 0.03 ohms. It can be seen from this that to determine whether industrial pipeline metal flanges need to be bridged, 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. Flange bridging for gas pipelines: Gas is widely used by enterprises, so what are the regulations regarding flange bridging for gas pipelines? The \"Code for Design of Urban Gas\" (GB50028—2006) does not contain any explicit provisions regarding flange splices; instead, paragraph 3 of Article 10.8.5 states that the design of anti-static grounding systems for gas pipelines and equipment shall comply with the provisions of the current standard \"Technical Regulations for Anti-static Grounding in Chemical Enterprises\" (HGJ28-90). 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; the surfaces should be descaled and degreased before installation, and anti-loosening 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, between metal flanges connected by metal bolts, the connection itself via those bolts is sufficient to ensure adequate static electricity conductivity. The installation requirements under corrosive conditions are intended to ensure conductivity. It can be seen from this that when metal flanges are fastened using metal bolts or clamps, it is not necessary to use a bridging wire for the gas pipeline flanges. Since most gas pipelines are industrial pipelines, if the flanges of such pipelines suffer severe corrosion and the resistance value exceeds 0.03 Ω, bypass wires can be used in accordance with the requirements of the \"Regulations on Safety Supervision of Pressure Pipelines – Industrial Pipelines\" (TSG D0001–2009). III. Bridging of petrochemical pipeline flanges: Petrochemical companies have high requirements regarding anti-static measures. Are there stricter regulations for bridging pipeline flanges? Article 8.9.1 of the \"Code for Acceptance of Construction Quality of Metal Piping in Petrochemical Industries\" (GB50517-2010) stipulates that for pipelines requiring static grounding, a conductor bridge shall be provided when the resistance value between each pair of flanges or threaded joints is greater than 0.03 Ω. The \"Code for Design of Static Grounding in Petrochemical Industries\" (SH 3097-2000), 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 of the bolts or clamps. Article 6.2.13 of the \"Code for Construction and Acceptance of Petrochemical ** and Flammable Medium Pipeline Projects\" (SH 3501‑2001) stipulates that for pipelines requiring static grounding, good electrical conductivity must exist between each section of the pipeline. When the resistance value between each pair of flanges or threaded joints is greater than 0.03Ω, a wire should be used for bridging. Article 14.2.14 of the \"Code for Design of Oil Depots\" (GB 50074-2002) 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 a non-corrosive environment. Article 10.3.3 of the \"Code for Design and Construction of Automobile Fuel and Gas Stations\" (GB 50156—2002) stipulates that in areas at risk of 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 less than 5 connection bolts on the flange, bypass wiring is not required in non-corrosive environments. As the industry standard for static electricity safety inspections, the \"Regulations for Static Electricity Safety Inspections in Chemical Enterprises\" (HG/T23002-92) stipulates in Section 5.1.2 that when metal equipment is connected to other metal equipment or pipes are connected to each other using metal flanges, it is not necessary to use additional bonding wires; however, there must be at least two bolts used for the connection. It can be seen from this that whether flanges on petrochemical pipelines need to be bonded depends on their resistance value or the number of bolts used; it is not necessary to bond them all. IV. Conclusion In summary, it is not necessary to bridge all metal pipe flanges.  Whether a bypass is required depends on whether the design documents specify requirements for static electricity grounding.  If the design documents are not available, it is necessary to determine the value by measuring the resistance; when the resistance between the flanges exceeds 0.03Ω, a wire must be used for bridging.  It is determined whether a bypass is needed based on the flange fastening method or the number of metal bolts.  It is suitable for gas pipelines and pipelines in petrochemical plants; flange static connection plates and flange static bypass wires are not applicable to common industrial pipelines.

The anti-static grounding is not determined by the number of flange bolts, but rather by the measured resistance value. The requirements for static grounding are as follows: According to Article 80 of TSG D0001-2009 \"Regulations on Safety Supervision of Pressure Pipelines – Industrial Pipelines\", for pipelines that require static grounding, it is necessary to measure the resistance value of each connection joint as well as the resistance value of the pipeline system relative to the ground. When the resistance value exceeds the values specified in GB/T 20801 or in the design documents, bypass wires (between flanges or threaded connections) and grounding wires should be installed. GB/T20801.4—2006 \"Code for pressure pipelines – Industrial pipelines, Part 4: Fabrication and installation\" 10.12 Static grounding 10.12.1 For pipelines that require static grounding, good electrical conductivity should 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. 10.12.2 When the earth resistance value of the piping system exceeds 100Ω, measures should be taken or two grounding leads should be provided. The grounding lead should be welded. 10.12.3 For stainless steel pipes and titanium pipes that require electrostatic grounding, the wire bonds or grounding leads shall not be directly welded to the titanium or stainless steel pipes; instead, a grounding plate made of the same material as the pipe itself should be used as a transition element. 10.12.4 After the static grounding installation is completed, it must be tested; if the resistance value exceeds the specified limit, adjustments should be made. 4.1.5 The electrostatic grounding connection of the pipeline shall be completed before insulation work and painting. 4.2 Static grounding installation 4.2.1 Pipelines for combustible gases, liquefied hydrocarbons, combustible liquids, and combustible solids shall be equipped with static grounding facilities at the following locations: a) At the inlet and outlet of the device or facility ； b) Boundary of explosive hazard areas ； c) Pipeline pumps and their filters, buffers, etc. 4.2.2 An electrostatic grounding system shall be installed in the polyolefin resin treatment systems, conveying systems, and silo areas; there shall be no isolated conductors that are not grounded. 4.2.3 For long-distance unbranched pipelines, they shall be reliably connected to an electrostatic grounding electrode every 100m. 4.2.4 When the clear distance between parallel pipes is less than 100 mm, jumper wires should be installed every 20 m. When pipes intersect with a clear distance of less than 100 mm, bridging wires should be added. 4.2.5 For metal connection flanges between pipelines carrying combustible gases, liquefied hydrocarbons, and combustible liquids, as well as between pipelines and equipment or valves, when these are fastened using metal screws or clamps, it is not necessary to install additional static electricity bonding wires. 4.2.6 For the connection flanges between pipes used for transporting flammable solid materials in powder or granular form that are prone to generating static electricity, as well as the connection flanges between pipes and equipment or valves, bonding must be carried out, and they should be reliably connected to an electrostatic grounding electrode every 100 meters. 4.2.7 The heating tracing for process pipelines shall be equipotentially connected to the process pipelines at the steam inlet and return water outlet of the tracing. 4.2.8 When the protective covers for air ducts and insulation layers are made of thin metal sheets, they should be joined by butt joints, and equipotential connection should be achieved using bolts and other means for mechanical fixation. 4.2.9 For the non-metallic sections located between metal pipes, in addition to requiring special anti-static treatment, the metal pipes at both ends should be connected to the grounding wire respectively, or they should be bridged with multi-strand copper-core insulated wires having a cross-sectional area of not less than 6 mm² and then grounded. 4.2.10 All metal components on non-conductive pipe sections shall be grounded. 4.2.11 Metal pipes buried directly underground may not require electrostatic grounding.

Where do sections 4.2.1-4.2.11 come from?

QSH 0700-2008 Specifications for the Electrostatic Grounding Design of Pipelines

It’s available online; I downloaded it before.

Thank you for the advice; a big problem has finally been solved!

I had looked into this question before as well, but after reading it, I understood it even better. There is a question: which pipes need to be grounded?