Power Washing and Roof Cleaning Forum

A downstream injector, also known as a chemical injector or soap injector, is a component commonly found on pressure washers. It is used to introduce cleaning chemicals or detergents into the high-pressure water stream generated by the pressure washer. The downstream injector works by drawing the chemical solution from a separate container or reservoir and mixing it with the pressurized water before it exits the nozzle.

Here's how a downstream injector typically works:

1. Chemical Reservoir: The pressure washer is connected to a chemical reservoir, often a container or bottle filled with the appropriate cleaning solution or detergent.

2. Hose Connection: A hose or tubing is connected to the chemical reservoir and the downstream injector.

3. Injector Placement: The downstream injector is usually located on the outlet side of the pressure washer pump or at a point after the high-pressure water leaves the pump. This ensures that the chemical is introduced into the water stream after it has been pressurized.

4. Venturi Effect: The downstream injector operates on the principle of the Venturi effect, which involves a reduction in pressure when fluid flows through a constricted section of a pipe or tube. As the high-pressure water flows through the injector, it creates a vacuum that draws in the chemical from the reservoir.

5. Mixing: The chemical is mixed with the high-pressure water inside the injector, creating a diluted solution. This mixture is then delivered to the spray wand or nozzle.

6. Adjustable Ratio: Many downstream injectors have an adjustable control valve that allows you to regulate the amount of chemical that is mixed with the water. This gives you control over the concentration of the cleaning solution being applied.

7. Application: The user can then apply the combined high-pressure water and cleaning solution to the surface being cleaned, such as a car, driveway, deck, or building exterior.

The downstream injector is a valuable tool for pressure washing tasks that require the use of cleaning agents or detergents to effectively remove dirt, grime, mold, mildew, and other contaminants. It allows for efficient and controlled chemical application, making it easier to clean a variety of surfaces effectively.