Ways to Conserve Water in Plating


Conserve water

Years ago Ted Mooney wrote a piece called “20 ways to cut water usage in plating shops” that is still applicable today. So I won’t repeat what he has written previously but emphasize a couple of points. Specifically, points number 3 (spray rinsing) and 11 (rinse tank timing) are something Gizmo Engineering can help with. The third most important way to save water is to use top sprays. Ted writes:


If you handle ten loads per hour, and you spray for ten seconds each time a load is lifted, then water is running for only 100 seconds out of each 3600 seconds.

Thus you can install a powerful 36 GPM spraying system while consuming an average of only 1 GPM. Mount a top spray on a rinse tank, and you have a very effective two-stage rinsing system that consumes very little water.Automated lines can be programmed to spray during lift only; manual lines can be quipped with foot-operated valves or limit switches and timers.

Ted Mooney

A great way to conserve water is to consume fresh rinse water only for the time that you need to rinse the parts. And there are the advantages that the rinse water is cleaner than the water in immersion rinse tanks. Also, the rinse water sprays with some amount of force to blast residual plating solution from the parts. Finally, spray rinses don’t take any additional floor space.

However this is a daunting task for most plating shops to implement something as complex as programmed spray times. Unless a company has PLC programmers or electrical engineers on staff, or hires an expensive automation company, it seldom happens. What if there was an off-the-shelf unit that will accomplish all the electronics, so you can simply plug into a power outlet? Well, now there is. Gizmo Engineering has developed a timer that will detect the racks, and then open the water spray solenoid. The only thing left to do to start saving water is to fabricate spray bars. Most shops are comfortable with this. The T5 or T6 timers are AC powered and simply plug into wall power. It works by a sensor detecting the rack. This can be an inductive proximity switch if the location of the rack is precise, or for not-so-accurate rack placements, a lever-arm (or whisker) switch will also work.

Proximity Switch with Mounting Bracket

Proximity switches are the preferred method as they are immune to factory dirt, fumes and there are no moving parts to corrode. They will sense any metal object at a distance of up to 40 mm. Either switch will work to detect the rack. When the rack is lifted out of the tank, the sprays come on for whatever time you set. In addition, you can also set a delay to allow the rack to rise to the best position before spraying. This delay conserves even more rinse water because the spray is only spraying the minimum time that you decide is effective. Below is an installation showing a model T6 timer.