1. Material Testing: Check if the surface resistivity meets the standard. The core of antistatic performance is the material's conductivity, with surface resistivity being the key indicator. The ideal range is 10⁵–10⁹Ω.
Metal Cans (e.g., tinplate, galvanized steel): Natural conductors with extremely low surface resistivity (typically <10⁴Ω), possessing good electrostatic conductivity, but a proper grounding path must be ensured.
Plastic Cans: Ordinary HDPE is an insulator (surface resistivity >10¹²Ω), easily accumulating static electricity. Antistatic modified plastics should be selected, which reduce the surface resistivity to the 10⁶–10⁹Ω range by adding carbon black or conductive fibers.
Composite Structure Cans (Metal Shell + Plastic Liner): The outer shell can be grounded, and a conductive coating on the inner lining provides even greater safety and superior overall performance.
✅ Test Method: Measure the surface resistance of the can using a surface resistance tester (such as the instrument specified in GB/T 16906-1997) in a clean, dry environment. Measure at least 5 different locations and take the average value. The result should be between 10⁵ and 10⁹ Ω.
2. Structural Inspection: Does it have anti-static design and grounding capability?
Even if the material is qualified, the lack of a conductive structure still poses a risk.
Grounding Terminal or Metal Contact Point: A proper anti-static can should have an exposed metal grounding point or threaded interface for connecting an anti-static clip. Check if it is covered by paint and ensure that the coating can penetrate to contact the metal body.
Conductive Coating or Lining: Some plastic cans have a conductive layer containing carbon nanotubes or metal oxides on the inner wall, making the whole can conductive. The conductivity of the inner and outer surfaces can be tested with a multimeter.
Anti-static Labeling and Certification: Check if the product is labeled "Anti-static," "Antistatic," or complies with standards such as GB 12158-2024 "General Requirements for Prevention of Static Electricity Accidents" and HG/T2-59-78.
✅ On-site Testing Recommendations: Clamp the tank's grounding point with a toothed electrostatic clamp, connect the grounding wire, and use a grounding resistance tester to test the overall grounding loop resistance. It should be ≤10Ω (required for flammable and explosive environments).
3. Verification of Usage Environment and Operating Procedures: Safety under dynamic conditions: Passing static testing does not guarantee safety during use; it must be evaluated in conjunction with actual operating conditions.
Ambient Temperature and Humidity Influence: At low humidity (<40%RH), non-conductive materials are more prone to static charging; while increased temperature reduces resistance, it also accelerates solvent evaporation, increasing the risk of explosion. Testing is recommended at 20℃±5℃ and 40%–60% humidity.
Filling Method and Flow Rate Control: Top-pour and high-speed filling can easily generate splashing and static electricity from friction. Bottom-feeding or loading arms extending below the liquid surface should be used, with an initial flow rate ≤1m/s to avoid static buildup.
Anti-static Measures: All equipment (pumps, pipelines, receiving containers) must be bridged and grounded to form an equipotential system.
Operators must wear anti-static clothing and conductive shoes, and touch the static discharge column before entering the tank.
For high-risk scenarios, an electrostatic connection monitoring system can be installed for real-time alarms.
⚠️ Special Reminder: According to national regulations, the inner wall of oil tanks must be coated with anti-static paint, and the surface resistivity should be less than 10⁹Ω. If paint tanks are used to store such paints, they themselves must also meet anti-static requirements.
