Psi stands for pounds per square inch and is a unit measuring the pressure exerted on one square inch.

Feet, on the other hand, is a unit of length or distance. There is no relation between these two units and they can therefore not be converted into one another.

In some water treatment plants, the pressure exerted by the water in a water tower is used to determine how full the tower is. This is done under the assumption that one psi equals 2.31 feet of water.

A much heavier/lighter fluid would exert a different amount of pressure per square inch. Therefore, this equation applies to water only, and cannot be used as a general conversion factor.

If the question is related to foot pounds, a unit measuring the force in pounds applied in circular motion at a radius of one foot, generally referred to as torque, a vague relationship may be calculated.

It must, however, be noted that this relationship is much like that of a sparrow and a vulture. Both are birds, but that's just about all the two have in common.

Defining this relationship is best done as follows:

Assuming there is no friction, one would have to apply one psi to a cylinder having a one inch surface area, attached to an arm of one foot length in order to exert a torque of one foot pound per one foot radius.

In reality, a cylinder of this size would itself have a resistant force of approximately 14 psi. Consequently, 15 psi has to be applied to achieve the required force of one foot pound on the one foot arm.

On a final note, one psi equals a pressure of one pound per 0.0069445161290 square feet, or 144 pound per one square foot.

Feet, on the other hand, is a unit of length or distance. There is no relation between these two units and they can therefore not be converted into one another.

In some water treatment plants, the pressure exerted by the water in a water tower is used to determine how full the tower is. This is done under the assumption that one psi equals 2.31 feet of water.

A much heavier/lighter fluid would exert a different amount of pressure per square inch. Therefore, this equation applies to water only, and cannot be used as a general conversion factor.

If the question is related to foot pounds, a unit measuring the force in pounds applied in circular motion at a radius of one foot, generally referred to as torque, a vague relationship may be calculated.

It must, however, be noted that this relationship is much like that of a sparrow and a vulture. Both are birds, but that's just about all the two have in common.

Defining this relationship is best done as follows:

Assuming there is no friction, one would have to apply one psi to a cylinder having a one inch surface area, attached to an arm of one foot length in order to exert a torque of one foot pound per one foot radius.

In reality, a cylinder of this size would itself have a resistant force of approximately 14 psi. Consequently, 15 psi has to be applied to achieve the required force of one foot pound on the one foot arm.

On a final note, one psi equals a pressure of one pound per 0.0069445161290 square feet, or 144 pound per one square foot.