Do not overpressurize. Pressure is good. Without it, most power and manual sprayers won’t work. But too much pressure decreases sprayer life. Here’s an interesting observation. When we build a new gas-powered pest spray rig, we install it, test it and send it out at 75 to 100 psi. When spray rigs come into our shop for service, the rigs are often set at 150 psi or higher. The pressure isn’t magically increased by a pressure fairy. Pest control technicians turn up the pressure to finish jobs faster. Higher pressure shortens the life of pump, hoses, fittings and guns. Chemical spills will be more dangerous if a component bursts at higher pressure, which also can affect spray droplet size and cause spray drift. Make sure techs are operating pest control power sprayers at the recommended pressure.
Release the pressure. Another way to reduce spray equipment problems is to release the pressure. Release it on the (power or manual) sprayer after each stop by squeezing the spray gun handle to let the pressure drop in the line. The power sprayer must be turned off, and the manual sprayer must not be pumped up. If spraying extra chemicals is problematic, open the lid of the sprayer tank and spray the product back into the tank.
Releasing the pressure in the sprayer extends the life of hoses, O-rings and gaskets. We used to suggest releasing the pressure at the end of the day, but technicians forget and sprayers end up stored under pressure all night. It’s better to train the technicians to release the pressure at the end of each stop. Temperatures on trucks are higher than ambient temperatures, so the pressure in the system will increase if not released.
Releasing the pressure also reduces the chance of freeze damage should a deep freeze occur. If the sprayer is stored under pressure and the temperature drops, the frozen water will expand and break the weakest link in the system.