Whether the flowing material is sea water, oil, paint or a variety of food or chemical products, there is often something present that can cause trouble. Dirt, foreign matter, or even clumps of the product itself can clog or damage pumps, spray nozzles, condensers, and similar equipment. Sometime a finished product has to be rejected because of the presence of undesirable solid matter. Basket strainers remove unwanted particles from pipeline flow.
An official definition adopted by the Fluid Controls Institute is: A closed vessel with cleanable screen element designed to remove and retain foreign particles down to 0.001 inch diameter from various flowing fluids. Strainers do not necessarily remove only dirt. They take out material which is not wanted in the fluid and this can sometime be a valuable product which may be saved.
An important feature of a well designed duplex basket strainer is that it must never allow the flow to stop. If this is possible, a careless workman can inadvertently do great damage. For instance, the flow of lubricating oil to a compressor could be shut off while switching from one basket to the other. With a properly made duplex strainer it should be impossible to stop the system. If this is required, a separate valve can be used.
