## Collapse Strength Calculations

The following collapse formulae provide the user practical tools to estimate collapse strengths of various types of casing and screen. It is important that one pays particular attention to the material and manufacturing standards for the casing and screen specified so that acceptable tolerances are considered and adequate safety factors applied.

## Weight Calculations

Weight of a blank casing, or pipe, can be found using the following formula.

## Yield Strength Calculations

Users must determine the yield strength for casing and screen. This measures the point at which the casing or screen will be damaged by deformation due to the stress of the hanging weight. This calculation is used to evaluate suitability of use relative to expected loads.

## Area/Flow Calculations

Well Production at AWWA Standard of 1.5 feet per second: To calculate the flow in gallons per minute per foot of screen, first calculate the percentage of open area of the screen, then use that result to calculate the flow. Determine the open area for the type of screen used then convert area to a percentage. Then multiply the percentage by 12 inches per foot, by the outside diameter, by pi, and the conversion constant of 4.8: