The screen or basket is the heart of the SAINATEC strainer. The media flows into the open end of the screen or basket and is strained as it passes through the screen toward the outlet. All particles larger than the screen opening are trapped inside. Screens are provided in perforated metal or wire mesh, depending on strainer size and/or material being strained. Only the best materials of the proper gauge to suit the service are used. All seams are spot welded for maximum strength. Double or reinforced screens are spot welded on the end peripheries as well as the seams.
Reinforced screens consist of a perforated sheet lined with wire mesh. SAINATEC engineers have designed the screens to provide maximum total screen area Mesh sizes is related to number of openings per linear inch. All meshes shown are available in carbon steel. 304 S.S. and 316 S.S. Many other meshes and materials are available.
There are two types of screens used in strainers:
These are formed by punching a large number of holes in a flat sheet of
the required material using a multiple punch. The perforated sheet is then rolled into a tube and spot welded together.
These are relatively coarse screens and hole sizes typically range from 0.8 mm to 3.2 mm. Consequently, perforated screens are only suitable for removing general pipe debris.
Fine wire is formed into a grid or mesh arrangement. This is then commonly layered over a perforated screen, which acts as a support cage for the mesh.
By using a mesh screen, it is possible to produce much smaller hole sizes than with perforated screens. Hole sizes as small as 0.07 mm are achievable. Subsequently, they are used to remove smaller particles which would otherwise pass through a perforated screen. Mesh screens are usually specified in terms of \\\’mesh\\\’; which represents the number of openings per linear inch of screen, measured from the centre line of the wire. the following picture shows a 3 mesh screen