Submersible well pumps are often used in water storage tanks. When mounted vertically, as they were designed to be, there is a lot of water that cannot be pumped from the tank. The reason for this is the design of the pump. Most submersible well pumps are designed with the motor under the pump. This picture shows a Sta-Rite pump with a Franklin motor mounted below. The pump intake is over the motor and below the pump.

This arrangement means that, with the pump mounted in the vertical position and the motor resting on the tank bottom, the minimum operating water depth for a ½ HP pump is about 11" - 11" of water can't be used. The addition of the "Flow Inducer Sleeve" recommended by Franklin Motors will not change this.

This is the reason that you often see pumps lying horizontally in the bottom of a tank installed in a "Flow Inducer Sleeve."

Franklin Electric manufactures approximately 90% of all the motors used in submersible well pumps. They point out that their motors are designed for use primarily in the vertical position and that although they can be used in other than the vertical position, the further the mounting position is from vertical and the closer to horizontal, the more likely you are to shorten the operating life of the motor. SEE http://www.franklin-electric.com/Manual/AIM_03.htm .

Franklin also requires a flow sleeve in certain conditions - SEE http://www.franklin-electric.com/Manual/AIM_06.htm . The use of a flow sleeve is required when submersible pump motors are used in the horizontal position anywhere or when mounted vertically in dug wells, large bore wells, storage tanks, cisterns, open bodies of water and similar installations.

Picture shows a 1/2hp submersible well pump standing next to a PumpChamber with a similar pump installed in it. The PumpChamber is delivering water from a tank with 2 ½" of water in it. The screened intake of the standard submersible pump is high and dry.

The reason for the sleeve requirement is that a certain minimum flow rate is required across the motor to provide adequate cooling to assure maximum motor longevity.

A ½ HP submersible pump mounted in a "Flow Inducer Sleeve" lying on the bottom of a tank will change the minimum operating level from 11" to 6" or 7" of water. Even so, there are other limitations that result from laying the pump down.

Submersible pumps are long. A ½ horsepower pump with motor is about 22" long and a 1.5 HP pump might be 31" long without any piping connected. When used in tanks the size of the pump can be limited by the tank diameter unless you are willing to mount the pump vertically and give up use of 11" to 15" of the stored water depending on pump size.

A PumpChamberT allows you to pump all but 21/2" of the water from tanks, cisterns, dug wells or open bodies of water of any shape or diameter using a vertically mounted submersible pump of any length while providing proper motor cooling.