Dome shafts are manholes in the roads at petrol stations that provide access to the fill openings of underground tanks. Every ‘dome’ in the cover of the underground tanks contains the following features at a minimum:
- A hose connection for the tanker
- A hose connection for returning the gas-air mixture to the tanker for air purification (gas displacement method) for super-unleaded or unleaded petrol
- An electrical connection for overfill safety
- A unique identifier (label)
- A dip stick.