Included:
Header / Expansion tank - item 2 in Exploded diagram
Pressure cap 75 Kpa  - item 3 in exploded diagram
 

Dimensions
Length =  210mm
Width = 125mm
Height (to the base of tank and not inc cap) = 100mm

Other items in exploded diagram do not come with this tank.

Used for adding to standard engine cooling system.

A header tank is added to a standard engine cooling circuit to allow for the extra expansion of extra coolant when adding a calorifier and plumbing to the engine.

Most engines will expel excess coolant from the header tank as the engine heats up to full operating temperature.

When the engine cools and the coolant also cools and contracts it will find the correct level for normal operation.

BUT when the coolant circuit has additions such as Calorifiers or heaters added to the circuit the loss of coolant increases when the engine is hot due to the extra volume of water now added to the circuit.

When the engine is allowed to cool the coolant therefore contracts and can cause the natural level in the engine to be dangerously low and cause problems of overheating and loss of coolant flow.

It would be essential to increase the area of expansion and height of the coolant in the engine circuit by adding a header tank to the circuit.

Also used as an expansion tank for closed systems on diesel fired water heaters and matrix heaters to prevent loss of coolant and to permit air bleeding from heater to top of tank return pipe.