Strainers remove debris from the flow to reduce the risk of damage to equipment such as pumps, chillers, and boilers. Suction diffusers are a specialized type of strainer used for direct attachment to specific pumping-equipment inlets where compact and accessible pipeline straining is needed.
What is a Strainer?
Strainers provide a means of mechanically removing solids from flowing fluid by using a perforated metal, mesh, or wedge wire straining element. They protect downstream mechanical equipment such as heat exchangers, pumps, meters, and steam traps from the detrimental effects of sediment, rust, pipe scale, or other extraneous debris.
The most common configurations of strainers are wye (Y) and tee (T).
What is a Y-Strainer?
Y-strainers have a Y-shaped body with a strainer basket oriented at an angle. This design promotes debris flow out of the main water flow path for less obstruction and pressure drop during operation. Vertical piping, frequently found at the pump inlets, necessitates the use of a Y-strainer. A Y-strainer in vertical piping must be placed with its screen downward to trap the sediment in the debris collection chamber.
What is a Tee Strainer?
Tee strainers feature a T-shaped body that orients the strainer basket 90° to the main flow. Tee strainers provide excellent flow characteristics and are typically lighter and more economical than wye strainers. Strainers can have either grooved or flanged ends.
Types of Tee Strainers:
Basket Strainers
Most basket strainers are intended for horizontal or slightly inclined piping. Special attention should be given to the orientation of the debris collection chamber and the drain or blowdown. Refer to the manufacturer’s installation and operating manual for specifics. The strainer must be installed at the lowest possible position.
Magnetic Strainers
Magnetic strainers are an effective solution to the problem of excessive and premature wear to pump seals and wear rings. A standard strainer is fitted with magnets which are removed for cleaning. These magnets are spaced and arranged to create a magnetic field around the screen’s interior and attract fine ferrous (magnetic) particles, which could damage downstream equipment.
Regardless of the type of strainer used, they all essentially function similarly. A bonnet allows access to the strainers for cleaning and can be grooved or flanged/bolted. The bonnet is tapped and fitted with a ball valve to allow draining and “blowdown.” Blowdown is the process of opening the ball valve during operation to expel debris while the system is in operation. Blowdown is not a recommended substitute for complete removal and cleaning (“mucking out”) of the basket but can periodically assist performance.
What is a Suction Diffuser?
Suction diffusers are a type of strainer. They are a combination elbow, reducer, strainer, and straightening vane that works to provide maximum flow efficiency at the suction inlet of the pump while at the same time reducing space and fitting requirements. In addition, they remove large particulates from water and process liquids to prevent damage to pumps or other system components. Suction diffusers are found in many commercial and industrial applications.
Read our previous blog post: What is a Suction Diffuser?