Simply put a strainer is a component that has a perforated or wire mesh cylinder within the body of the component that causes impurities in the fluid stream to be captured and ultimately flushed out of the system. The fluid enters the body of the strainer, flows into and through the mesh cylinder. The mesh cylinder “strains” out particles such as rust, dirt and other foreign objects, within the fluid stream. Strainers catch larger particles that can interfere with proper operation of valves, steam traps, pumps, flow control valves and just about any component that has moving parts that could be hampered by the particles if not strained out of the fluid stream.
The most common type of strainer in most piping systems is the “Wye” Strainer. The name is derived from the fact that the shape of the strainer resembles a “Y”.
Below is a typical “Wye Strainer”
Wye strainers are usually used for course filtration; however a fine mesh can be used in some instances. Also the Wye strainer has a “blow down” feature so it is not necessary to remove the mesh each time the strainer is cleaned.
The next most common type of strainer is the “Basket Strainer”, again the name is derived from the shape of the strainer. Basket strainers are generally used where high flow capacity is required. The basket strainer is serviced by removing the cover, which gives access to the basket. The basket is removed, cleaned and replaced. Basket strainers are also available in a duplex style. The duplex feature allows one strainer basket to be cleaned without any interruption to the flow of the process fluid.
Below is a typical “Basket Strainer”
What is the difference between a filter and a strainer? A filter is a device that removes particles from a given liquid or gas. It includes a disposable medium for removing particles of specified micron sizes. A strainer is also a filter; however, a strainer uses a perforated plate or screen mesh to remove larger particles from a process stream.
The major advantage of a strainer is that it is reusable. The mesh or screen is removed from the component, cleaned and replaced. Strainers can be fitted with several different “mesh” sizes, the most common is any where from a 16 mesh (0.0469”) or 1190 microns to a 25 mesh (0.0280”) or 707 microns. To put the mesh or micron size into context a human hair is approximately 50 microns, the human eye cannot see anything smaller than 40 microns in size.
Their strange shape and the need to access and clean the filter means that wye filters are typically left bare in otherwise insulated industrial systems. This can lead to component failure, since the stresses of temperature ranges experienced outside of those felt by the rest of the system can be taxing on the materials the wye strainer is built out of.
Additionally, uneven wear due to unequal distribution of heat energy can further damage or stress uninsulated components. Even if component damage is not a primary concern, wye strainers can be a source of energy inefficiency in an otherwise smartly insulated plant. For better efficiency, it’s best to incorporate removable insulation.
For more information on insulating Wye strainers, visit our products page.
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