Designed to prevent drawdown and increase well production in low water level wells
The LEMCO SEAL protects the submersible pump by keeping it submerged in water and by preventing it from sucking air which can lead to motor burnout and damaged impellers. It does this by forcing the submersible pump to draw from the aquifer below, instead of lowering the static water level above the pump. During dry spells, when the static water level lowers naturally, cavitation and pump failure can result. Wells made in fine sand are especially vulnerable to drawdown. Even when there seems to be plenty of water, a fine screen tends to restrict water flow, increase drawdown, and lower well production.
In the illustration, the submersible pump is submerged in water, pumping normally, unaffected by the amount of drawdown outside the well. To use an analogy, it's like sucking on a straw to raise the level of the liquid above the glass. The same holds true for the Lemco Seal which takes advantage of suction to raise the water level and keep the pump submerged in water. When the pump runs, a negative pressure or suction is put on the well which tends to increase well production. This makes the Lemco Seal ideal for preventing drawdown and increasing well production in low water level and slow producing wells.