To illustrate the water saving from using counter-current rinsing lets examine a typical plating operation using a Watts Nickel bath. A single rinse tank would need about 6,750 gallons of fresh feed water for each gallon of plating solution dragged into the rinse tank. While a triple stage rinse tank system would need only 18 gallons of fresh water feed. Counter-current rinse tank systems can be purchased new or retrofitted into an existing tank or series of tanks. In most cases the system will consist of a single tank divided into a series of compartments.
Water overflows from one compartment and enters the next through a submerged weir.
As in all properly designed rinse tanks, air agitation and flow control valves are used. Such a system is illustrated in the previous figure. These systems can be purchased new and ready to install or an existing rinse tank can be modified. Another approach is to place a second or third rinse tank into the process line and gravity feed or pump the rinse water from the last rinse tank to the first. Only a few inches of head is needed to gravity feed the water.