Constant level oilers are designed to maintain a predetermined oil level in a sump, which is necessary for proper lubrication.

If the oil level were to drop below this point, the depleted oil would automatically be replenished by the lubricator, returning it to its original level. With the use of constant level oilers, maintenance efficiencies can be increased, while minimizing maintenance costs, and the loss of production time.

The majority of constant level oilers available are adjustable, allowing for use in many applications. However, there are oilers available that do not allow for fluid level adjustability, eliminating potential installation errors. Typically, constant level oilers are mounted on the side of the equipment facing the direction of shaft rotation. Some oilers allow for bottom mounting, on the oil sump, which prevents the oiler from misfeeding during applications that contain currents and turbulence formed by slinger rings, discs, and high rotating speeds.

In most cases, constant level oilers are vented to the outside atmosphere to work properly. Since these oilers are vented to the atmosphere, especially in harsh, dirty environments, contaminants are allowed to enter the lubricating oil. These contaminants are in the forms of moisture and/or particulate which are extremely damaging to oil and equipment life.

In order to combat the potential for oil contamination, the closed system oiler was developed. These oilers are effective in minimizing and eliminating the ingression of contaminants into the oil sump, especially in dirty environments. Some closed system oilers contain a pressure-balancing line, which is connected from the headspace of the oil sump to an air chamber built into the surge body of the oiler.

This air chamber is sealed from the outside atmosphere in order to prevent the ingression of contaminants. Additional types of closed system oilers are available that mount directly on the centerline of the oil level to be maintained. The exchange of air between the oil sump and the oiler is at the oilers base, which is mounted directly to the oil sump.

Several different types of constant level oilers are available to meet the specific application needs, whether it is vented or non-vented, adjustable or nonadjustable they are an easy and effective method of maintaining proper oil level in equipment.

Constant Level Oilers are used to maintain the lubricant level in a piece of equipment the naturally depletes lubricant through use, wear, friction, misting or evaporation. As the lubricant is depleted in equipment, such as bearings, gearboxes, or pump housings due to its natural operation and the generations of heat from friction, the level of lubricant changes. A constant level oiler can be used to maintain optimum performance.