1. Mandatory Dual Grounding Connections
- Tanks ≥50 m³ or diameter >2.5 m must have at least two separate grounding connections.
- Points must be symmetrically arranged around the bottom perimeter.
- Spacing between grounding points must not exceed 30 meters.
2. Strict Grounding Resistance Limits
- Grounding resistance must generally not exceed 10 ohms.
- Connections should be arranged in a closed‑loop configuration at the tank base.
- Provides a highly reliable and redundant path for static charge dissipation.
3. Essential Bonding of Flanges & Accessories
- All metallic components (flanges, valves, pipe joints) must be cross‑bonded for electrical continuity.
- Top‑mounted accessories (breathing valves, safety valves, level devices) must be connected to the main tank.
- Prevents localized static accumulation on any attached component.
4. Specialized Grounding for Floating Roofs
- Floating roofs must be connected to the main tank body using at least two flexible copper cables.
- Minimum cross‑sectional area: 25 mm² to accommodate continuous movement.
- Ensures reliable static discharge path and prevents dangerous sparks.