Recovery Tanks are designed to catch overflow liquid and purge air during heat cycles. This enables the cooling system to remain full of water and minimizes maintenance. Keeping the system full decreases aeration and preserves pressure. As the temperature rises, the water expands and pressure builds. If the system is completely full, expansion pressure exceeds cap pressure and overflows into the recovery tank. If the pressure cap is properly located on the low-pressure side of the system, air is pushed out first. As the system cools, a vacuum is created. If the radiator cap has a valve that opens under negative pressure, it pulls coolant back into the system. The tube that extends to the bottom of the recovery tank transfers the coolant back to the radiator.
The recovery tank should be mounted as close as possible to the pressure cap. The line should be short and level to reduce restriction and the effects of gravity. If the tank is kept 1/3 full (with the engine cold), every heat cycle will automatically purge more air from the system. The opposite is true without a recovery tank or with improper pressure cap location: every heat cycle will push out water, which leaves more air space that can be compressed to lower the boiling point.Features
Expansion Tanks are also referred to as surge tanks, header tanks, and air separators. An expansion tank is used as a fill point when the top of a radiator is lower than an engine's water outlet. A properly plumbed expansion tank can fix many cooling problems associated with trapped air. The bottom of the tank is plumbed to the low-pressure (suction) side of the cooling system (after the radiator core and before the pump impeller). The smaller fitting on the upper part of the tank is plumbed to the high points on the engine and radiator to remove trapped air and aerated water. Away from the main flow of water, this high reservoir allows air to be purged for a more efficient cooling system overall.Features