The Holte Manufacturing Oiler has a positive displacement pump that is air powered. The air gets to the pump through a solenoid valve. The solenoid valve gets a signal from an electronic timer that has a variable frequency set by the operator. Each pulse from the timer results in 1⁄2 cubic inch of oil. The pressure ratio between air supplied to the pump and oil coming out of the pump is about 4-1⁄2 to 1. This enables 100 PSI of air to push 450 PSI of oil. When the electronic signal is off, the pump recharges by means of a return spring in the pump. This simple system is durable and dependable.
A diagram on the face of the 7-1⁄2 gallon tank tells the operator the recommended amount of oil to use with the air volume he has available. It then shows where to set the knob for the desired amount of oil.
Holte now has barrel pump oilers that can be regulated to pump from one to five gallons per hour and another that can empty the entire barrel in minutes.