To empty or not to empty the MWF tank before vacation?

Keeping the fluid

Keeping the fluid in the sump saves money and reduces the environmental impact, but requires some preparation:

• Make sure that the process fluid is fresh and free of contamination. Check concentration, pH and bacterial levels.
• Empty the sump to a minimum level or about 50 percent of the sump volume, and add concentrate until you doubled the normal concentration. The high concentration makes the process fluid resist bacteria and microorganisms better. After vacation, fill with water so that you get the right concentration.
• If possible, air the liquid. Preferably by intermittent circulation or a simple aquarium pump.

You can clean the sump even if you save the fluid. Here's one way to go:

1. Let the volume drop to the minimum level in the machine sumps before emptying.
2. Empty the fluid in a clean, separate sump or in a clean IBC container (a cubic meter large plastic tank). Try to avoid sediment, leak oil and contaminants.
3. Increase the concentration in the filled container. Make sure that you have some circulation in it during the summer.
4. Clean the sump.

Send to destruction

If the process fluid is in bad condition and does not survive three to four weeks of production downtime, emptying can be the only way out. Keep in mind that:

• Clean tanks and chip conveyors so that you can start on a new track after your holiday. In order not to face the same situation next year, you should also introduce procedures and routines to keep the bacterial level down.
• Determine which process fluid is optimal for your system while at the same time the fluid is not a hazard to those who work with it. If you are considering to change to biocide-free metalworking fluid, here are five things to take into account.

Extend the life of the MWF

UV purification is a simple and a safe way of keeping the bacteria under control.