How should steel-reinforced polyethylene pipes and polyvinyl chloride pipes used for transporting oily wastewater be electrically grounded?

For steel-reinforced polyethylene pipes and polyvinyl chloride pipes used for transporting oily wastewater, the following static grounding measures should be observed: I. Steel-reinforced polyethylene pipes 1. The pipe body has a wire mesh reinforcement; during installation, this internal wire mesh reinforcement must be exposed and connected to the grounding device using special grounding clamps or wires. 2. Conductive bonding measures shall be applied at the pipe connections to ensure effective conductivity of the metal framework of the entire piping system, which shall also be connected to a reliable ground point. 3. The grounding system shall comply with explosion-proof specifications; generally, the grounding resistance is required to be less than 100 Ω. II. Polyvinyl chloride (PVC) pipes: PVC pipes are insulating materials and do not possess electrical conductivity, making it easy for static electricity to accumulate. For PVC pipes, the following measures should be taken: 1. Apply a conductive layer on the inner wall of the pipe, or install static-dissipative grounding rings or conductive inserts, so that any accumulated static electricity can be promptly discharged into the grounding system. 2. Regularly install metal pipe sections or static discharge devices through the piping system to perform static bonding, thereby effectively guiding the static charge within the pipes to the ground. III. Equipment and Accessories: Equipment accessories such as valves, flanges, and elbows must be bonded to ground to ensure smooth discharge of static electricity throughout the entire pipeline system. The aforementioned grounding schemes must be implemented in strict accordance with relevant anti-static and explosion-proof safety standards. They should also be regularly inspected and maintained to ensure safe operation. .

How is it possible for the internal steel framework to be exposed during construction? It must be kept secret! Conductive agents can be added to the pipe material to enable conductivity.

Special attention must be paid to the electrostatic grounding of steel-reinforced polyethylene pipes (PE pipes) and polyvinyl chloride pipes (PVC pipes) used for transporting oily wastewater, as oil-based fluids tend to generate static electricity during flow, and plastic pipes have poor electrical conductivity, which can pose a risk of static discharge. The following are the specific grounding measures and precautions: 1. Steel-reinforced polyethylene pipe (PE pipe reinforced with steel mesh/strip). Structural characteristics: A steel framework (steel mesh or steel strip) is embedded within the polyethylene pipe, and this framework can serve as a conductive path. Grounding measures: Grounding using the steel framework – The steel framework at the pipe connections is led out through metal clamps or specialized grounding terminals, and connected to the grounding grid using copper wires with a cross-sectional area of ≥6 mm². The grounding resistance should be ≤10Ω (in accordance with anti-static standards). Note: Ensure that the steel skeleton is electrically continuous at the joints. If electrofusion bonding is used, verify whether the steel skeleton remains continuously conductive. Bridging treatment: Connections such as pipe flanges and valves must be linked using bridging wires (copper braid or wires) to prevent non-conductive gaskets from blocking the static electricity path. Grounding spacing: A grounding point should be installed every 30 to 50 meters; additional grounding points are required at key locations such as elbows and branch pipes. Special requirements: If the medium being transported is flammable and explosive oils such as gasoline or diesel, it is necessary to comply with the Industrial Pipeline Code GB 50235-2010 and the Design Standards for Oil Depots GB 50074-2014; this may require an increased grounding density or the use of explosion-proof static eliminators. 2. Polyvinyl chloride pipes (PVC pipes) Structural characteristics: Pure PVC pipes are non-conductive; static electricity must be dissipated through external measures. Grounding measures: Conductive coating or metal shielding layer: If the pipe has a conductive coating or metal foil layer (such as anti-static PVC pipes), it can be grounded through the metal layer, using the same method as for PE pipes with a steel framework. Internal installation of metal conductors: Copper strips or spiral steel wires are laid on the inner wall of the pipe, with connections to ground at both ends (corrosion protection is required); this method is suitable for high-risk environments. External grounding ring/electrostatic conductor: Copper tape is wound around the outer wall of the pipe or a metal ring is installed to connect to the grounding wire. It is necessary to ensure tight contact with the pipe surface (conductive adhesive can be used). Use of anti-static additives: Adding conductive materials such as carbon black to some PVC pipes can reduce the resistivity, but grounding is still required as a supplement. Note: PVC pipes have limited grounding effectiveness; if there is a high risk of static electricity in the medium (such as when the flow rate is >1 m/s or the medium contains impurities), it is recommended to use PE pipes with a steel framework or metal pipes instead. General requirements – Grounding system: The grounding electrodes shall be galvanized angle steel/copper rods, with a burial depth of ≥0.6 m; the spacing between multiple grounding electrodes shall be ≥2.5 m. The grounding wire must be corrosion-resistant (such as copper-core insulated wire or galvanized flat steel). Testing and maintenance: Measure the grounding resistance regularly (once during the rainy season and once during the dry season) to ensure it remains ≤10Ω. Check whether the jumpers and clamps are loose or corroded. Flow rate control: Reduce the flow rate (usually ≤1 m/s) to minimize static electricity generation. Reference standard: GB/T 20801-2020 Code for pressure pipelines – Requirements for antistatic protection of industrial pipelines. GB 50074-2014 Code for Design of Oil Depots: Static electricity protection for pipelines carrying flammable liquids. HG/T 20675-1990 Code for Design of Static Grounding in Chemical Enterprises. It is recommended to commission a professional agency to design the grounding scheme based on the specific properties of the medium (such as conductivity and flammability) and the piping layout, to ensure compliance with safety standards.