Temporary strainers are designed to provide 100% or more open area in the cone or basket prior to the addition of wire mesh. The common is 100%, 150%, 200% and 300% open area for each size of strainer in both cone and basket configurations. These lengths are based on perforated metal with 1/8” diameter holes on 3/16” staggered centers and having 42% open area in the flat.
When using a flat strainer, or pancake strainer, with this material the open area is 42%. A flat strainer is recommended only for applications where there is not enough room for a cone strainer or basket strainer to be installed. In order to offer 100% or more open area, the perforated material must be designed in a cone or basket shape and lengthened to allow for the addition of wire mesh, if any.
