Almost all Powder Coating Guns use a Venturi Type injector pump to bring the powder material from the container, whether that is a Box Feed Unit or a Hopper Feed Unit.

Air is injected into the pump creating a venturi across an opening, this pulls the powder up from either a Box or a Hopper.

Injector pumps also use Supplemental Air, sometimes called Dosage Air, that is mixed directly with the powder as it is sent down the hose to help break the powder up and create a more even mixture. The relationship between these two plays an important role in the way your spray pattern looks and flows onto the part.

As with any pieces of equipment with moving parts, there are always maintenance items that must be replaced on a regular basis to maintain proper operation.

The illustration above shows a Wagner PI-P1 Injector Pump, which up is quite possibly my favorite injector pump to use because the even mixture of the powder and it's ease of use and maintenance. The item on this pump that gets the most wear is of course the Clearance Collector Nozzle (also known as the Venturi Throat). This is where all of the powder and air mixture gets sent through and is the connection for the powder hose. The brass Injector Nozzle should also be looked at to verify that it is not bent or worn, which would cause the air to enter the Clearance Collector Nozzle off center and cause uneven wear. There are 4) O-RIngs that must also be checked on a regular basis, 2) on the top of the pump and 2) on bottom. The O-Rings on the bottom of the Injector Pump are important because we don't want air to get pulled in from outside instead of powder, this can cause powder "surging" at the gun other problems. These are Conductive O-Rings, which is important for proper grounding of the Injector Pump. Due to powder and air constantly moving around in the pump, static electricity can build up and discharge. This can cause an uncomfortable "shock", but can also cause sparking, which is not a good thing around airborne powder, as it can combust and cause real damage to yourself and your equipment.

If you have any questions or concerns about your powder gun or your powder system, please CONTACT US. We are always happy to help!