The OverSized Cage was developed by Don-Nan to increase pump performance in gassy wells. The effect of this unique design is twofold. The enlarged size of the cage allows gas to transfer through the pump with minimal interference.
Additionally, the OverSized Cage eliminates the need of a connecting part and allows the valves to be spaced closer together resulting in an improved compression ratio.
The Don-Nan OverSized Cage is a standing valve cage fitted directly to the hold-down mandrel and pump barrel. It allows fluid and particulates to travel through valves with less disturbance, reducing gas breakout in the pump and increasing efficiency. It has an enlarged body compared to the equivalent API cage. Although the outside diameter has been increased, it continues to meet tubing drift requirements.
For maximum effect, combine an alternate pattern ball and seat with the Don-Nan OverSized Cage to increase pump efficiency in reducing gas interference.