The venture system solution
Bearing recent OSHA cases in mind, and considering the concern over the long-term effects of chemical exposure, product liability lawsuits, and lost productivity, many detailers would prefer a chemical dilution system that minimizes employee contact with undiluted chemical products.
A venture proportionator is a foolproof dilution control system which automatically adds the correct amount of chemical to the water. With this system, water flows through a specially designed tube that creates a vacuum in a side port. One end of the chemical feed line is attached to this side port and the other is attached to the container of concentrated chemical. The vacuum draws the chemical out of the container at the push of a button. A preselected metering tip determines the dilution rate by restricting the chemical flow through the port. For example, the smaller the hole in the metering tip, the higher the dilution rate. The larger the hole, the lower the dilution rate.
There are two types of venturi systems. The first system consists of a simple proportionator that can be attached to a wall. The chemical concentrates are placed on the floor below the proportionator and feed lines are dropped into each chemical to be diluted. You can purchase a single proportionator or as many as you need for however many water-based chemicals you use in your detail shop.
This type of system will dramatically improve control over chemical usage, and to a degree, improve worker safety. However, chemical containers can spill and when the container is empty, the worker must handle the feed line that has been in the concentrate container. This can be a problem unless the worker wears gloves.
The other type of venturi system is called a sealed system or closed-loop system. It consists of a venturi proportionator and feed line that is attached to a special fitting that is attached to a special chemical container, cartridge, or bag-in-the-box. This type of system will minimize worker contact the best. While several designs are available, the best ones dispense the product only when the product container is properly attached to the dispenser. Few detail chemical companies package their chemicals in a plastic bag in a cardboard box.
Keep your eyes on the size
The dilution rates of these systems are dependent on the height of the container in relation to the dispenser. The greater the height, the higher the dilution rate (providing a weaker chemical). This is a problem with the simple proportionator system that is attached to the wall.
Another problem is that dilution rates can vary depending on water flow rates. Systems will operate correctly if the flow rates match the recommended manufacturer rates, but can lose some accuracy if the rates are different. What you want to select are dilution systems with a fixed draw height and those that work across the widest flow rates.
These systems can be wall-mounted, and water flow is provided by a simple hose connection. However, because they are attached to the water supply, plumbing codes will require proper backflow prevention. Most plumbing codes require a minimum of a 1-inch gap between the clean water side and the product injection point. This prevents the chemical from being drawn into the water supply due to any changes in water pressure.
Be sure to select only the dispensing systems that have a built-in, 1-inch air gap. If you presently have a dispensing system, ensure that it has this 1-inch air gap. If it does not have the gap, you could be in violation of local plumbing codes. Your chemical supplier or dispensing system supplier can tell you if your unit has this 1-inch air gap.