Water Intake Screen Selection

There are several factors to be considered when selecting the appropriate surface water
intake screen design.

Select the intake screen type

Tee Screen or Cylinder Screen

If a current is present, tee intake screens with cones mounted on the upstream end
can be used to provide streamlining and deflect debris.  Tee intake screens can also
reduce the number of outlet connections required.  Tee intakes may be the answer to
shallow water problems.  The Tee screen design can be practical for large capacity
installations.

Cylinder intake screens may be more suitable for lakes and reservoirs.  They are
sufficient for low capacity applications. Cylinder intake screens can be less expensive.

Select the wedgewire size (wire width)

Generally,  .069" wide wedgewire is used for slot openings less than 1/4".  For larger
slot openings, 125" wide wire can be used.

Select the screen size(diameter)

Selection of the intake screen size is based on capacity calculations which rely on the
appropriate governmental regulations regarding the flow velocity and slot opening.

The capacities shown on the chart below were determined using the following criteria.

.5 fps maximum through slot velocity or .4 fps maximum approach velocity
based on a clean screen with .069" slot openings and .069" wire width.

Check the water depth

The available water depth should be at least twice the diameter of the intake screen.
Use the chart above to determine if the  water depth is sufficent for the selected intake
screen.  If not, pick a smaller screen diameter intake screen which may be used in the
available water depth.  Use the appropriate number of this size of intake to achieve the
desired capacity.

Air Burst Backwash System

Air burst systems are recommend unless the water is clean or if sufficient water current
is present to keep the screen clean.

_{Industrial Screen Products, Inc. 1997}