Eliminating static electricity in chemical PVC pipes
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The exhaust gas absorption pipeline of this device is made of PVC, and the materials handled include acetic acid, n-propanol, etc. Safety experts who inspected the site stated that an electrostatic discharge elimination device is necessary. I currently have several questions I would like to ask everyone: (1) Do chemical plants use the HG/T 20520-1992 standard for PVC pipes? (2) What are the effective methods for eliminating static electricity in PVC pipes? (3) According to Interpretation Note 2.2.2 of this standard, as long as the exhaust gas is within the lower limit of the allowable flow rate, can non-metallic pipes be exempt from static grounding? (4) The starting and ending points of non-metallic pipes are both metal equipment, and all such metal equipment is statically grounded. Can this be considered to eliminate the accumulation of static electricity?
If there are requirements regarding static electricity, it is recommended to use mining-grade PVC pipes, with a surface resistivity of
Can’t we use a common flange jumper?
In accordance with SH3097 5.3.7, for the non-conductive sections in metal piping, in addition to requiring special anti-static treatment, the metal pipes at both ends should be connected to the grounding main line respectively, or bridged together using copper stranded wire with a cross-sectional area of not less than 6 square millimeters and then grounded. And regarding the explanation of the stripes later on, there is a passage in section 1 stating that the idea that static electricity poses no risk as long as the equipment is grounded is incomplete; this concept must be clarified. Therefore, in (4), the start and end points of the non-metallic pipes are both metal devices, and these metal devices are all electrically grounded. Can this be considered to eliminate the accumulation of static electricity? This view is not very comprehensive
In the past, to eliminate static electricity in non-metallic pipes, 1.5 or 2.5 mm diameter bare copper wires were used to wrap around the pipes and then connected to the metal components at both ends of the pipes. The wrapping density did not need to be very high, as long as the bare copper wires were secured tightly in place.