Load/Discharge Techniques

Loading Methods

Gravity loading through manhole.
The cargo flows freely from an overhead storage tank through the manhole into the tank container.

Gravity loading through manhole.

'Closed system' gravity loading through top or bottom outlets.
The cargo flows into the tank container under gravity, the vapours are vented back to the storage tank via the airline connection.

'Closed system' gravity loading through top or bottom outlets.

Pumped loading through manhole.
The cargo is pumped from the storage tank through the manhole into the tank container.

Pumped loading through manhole.

'Closed system' pumped loading through top or bottom outlet.
The cargo is pumped from the storage tank through the manhole into the tank container.

'Closed system' pumped loading through top or bottom outlet.

Pressure loading through top or bottom outlet.
The cargo is loaded by top pressure in the storage tank. For sensitive or hazardous cargo, vapours are vented via the air-line connection to a vent tank or back to the storage tank.

Pressure loading through top or bottom outlet.

Discharge Methods

Gravity discharge.
The cargo flows freely through the bottom outlet to low-level storage tanks. Ensure adequate venting to prevent damage caused by vacuum.

Gravity discharge.

Pressure discharge.
The cargo is discharged through the top or bottom outlets by top pressure in the tank container.

Products carried under an inert gas blanket are normally discharged using nitrogen or another inert gas as the pressure medium. The maximum working pressure of the tank must under no circumstances be exceeded.

Pressure discharge.

Pumped discharge.
The suction side of a suitable pump may be connected to the top or the bottom outlets or to a hose via the manhole to pump the cargo to higher level storage tanks. Air or gas must be allowed into the tank container to replace the cargo being discharged. Depending on the nature of the cargo this can be achieved by opening the manlid or air-line connection, or by connection to an inert gas supply.

When using a high capacity pump it is recommended that a vacuum safety valve is incorporated in the suction line to protect the tank from vacuum collapse.

Pumped discharge.