Export Office: 21Floor, No.5 Nanhai Zhi Road,Qingdao, Shandong ,China
Work Shop: Beian Industrial zone, Qingdao,Shandong,China
+86 532 88550858
Martin
In places like oil and gas, chemical plants, or medicine factories, static bonding for pipeline flanges is a big safety step. Without it, static electricity can build up at flange connections. This can cause bad things like explosions, fires, or broken equipment.
Pipes and flanges are usually made of metals like carbon steel or stainless steel, which conduct electricity. But flange connections often can’t let static flow away because of conductivity problems.
The ability of a flange to conduct isn’t just about the metal. It depends on contact resistance between flange faces and bolts.
· Insulating Gaskets: To stop leaks, flanges use non-conductive gaskets like PTFE, rubber, or asbestos. These have high resistivity.
· Surface Oxidation and Corrosion: Being in air, water, or harsh chemicals forms oxide layers (like Fe₂O₃ on carbon steel or Cr₂O₃ on stainless steel). These have high resistivity Improper Bolt Connections:
o Loose, too few, or corroded bolts reduce contact pressure, creating gaps.
· Environmental and Operational Factors:
o Vibration: Flanges near pumps or compressors shake. This loosens bolts, lowers contact pressure, and raises resistance over time.
Not all pipeline flanges need static bonding. It depends on the stuff flowing, flange conductivity issues, and environmental risks. Here are the main cases where bonding is a must.
Pipes moving highly flammable liquids or gases—like gasoline, methanol, natural gas, or ethylene—need static bonding, even if the flange seems conductive. These materials catch fire easily and can mix with air to make explosive blends. Even a tiny spark can be disastrous.
· Flammable Liquids: Gasoline, methanol, ethanol, and acetone, used in fuel stations, chemical plants, or distilleries.
· Flammable Gases: Natural gas, liquefied petroleum gas, acetylene, and ethylene, found in gas networks, LNG terminals, or petrochemical plants.
· Other Media: Kerosene, diesel, or ammonia in refineries or fertilizer plants.
In a gasoline pipeline at a fuel station, fast flow (like 2 m/s) makes a lot of static charge. If a non-conductive PTFE gasket is used, the flange’s resistance can go over 10^6 Ω. This stops charge from leaving. It can create a voltage over 10 kV, causing a spark that could ignite gasoline vapor leaks.
Even with non-flammable stuff, static bonding is needed if the flange has high resistance from gaskets, rust, or bad bolting.
Non-conductive gaskets like PTFE or rubber block the conductive path completely. Bonding is a must. For example, in a chemical plant moving 30% hydrochloric acid (non-flammable but harsh), PTFE gaskets stop corrosion. Without bonding, static from fast flow can build up, risking gasket damage or shocks to workers.
Flanges in outdoor, wet, or coastal areas get oxide layers that raise resistance. For instance, in a coastal gas pipeline, rust can push resistance to 0.8 Ω in months. Bonding is needed to keep conductivity.
Loose or too few bolts, common near vibrating equipment like compressors, increase resistance. For example, a propylene pipeline flange with loose bolts saw resistance go from 0.02 Ω to 0.15 Ω. Bonding fixes this static risk.
Some settings and operations make static build-up worse. Bonding is needed even if flange resistance is close to okay.
In dry places (<30% humidity), like deserts or heated buildings, air doesn’t help static escape. Bonding makes sure charges go to the ground.
Pipes with fast flow or two-phase flows (like plastic pellets or coal dust) make lots of static. For example, a plastic pellet pipeline with gas at 15 m/s can create 5 kV across flanges. Bonding lowers resistance below 0.01 Ω.
Keep your pipeline systems safe from static risks with top-quality flanges from FLUIDO. They’re a leading forged flange maker in China. Their flanges meet standards like ASME, EN, DIN, and JIS, ensuring toughness and fit for your needs. Whether you want weld neck, slip-on, or blind flanges, FLUIDO has custom options. Contact their sales team for a free quote. Check out FLUIDO’s website or learn about FLUIDO Flange products. Make your pipeline systems safe and reliable with FLUIDO’s trusted know-how.
