Duplex Basket Strainer

A duplex basket strainer allows continuous process flow
when strainer basket requires cleaning.
Image courtesy Fabrotech

Liquid processing systems of many types and application require protection from particulate matter in the flow path. Often, there are mechanical components that cannot tolerate particulate matter greater than some maximum diameter. Pumps, valves, sensors, and other specialties can experience accelerated wear and tear, even clogging, from particulate matter entrained within the liquid flow.

Once the maximum particulate diameter has been determined for various portions of the system, a plan can be implemented that provides a properly sized and configured device in place to remove particulates larger than the greatest allowable size. It is conceivable that identifiable parts of a system will have differeing protection requirements, resulting in the use of several or many different filtration elements throughout the system. Filtration units can range from very small inline filter units protecting a single instrument, to large centralized high flow rate units protecting extended portions of the system.

A basket strainer will be an appropriate choice for many applications. Coordination of strainer housing connection size and type, along with design flow rate and pressure drop are in order. The materials of construction for the housing, strainer basket and other wetted parts should be evaluated for suitability with the process media. A final consideration is the holding capacity of the strainer basket itself. Too small a strainer will lead to a service frequency for cleaning that can prove cumbersome for operating personnel.

Regardless of the type of strainer or filter used, a key consideration is whether the system can be temporarily shut down, or the filter bypassed, while replacement or cleaning of the filtration element is accomplished. A basket strainer, one of several types of liquid filtration devices, is available in both simplex and duplex variants. A simplex basket strainer functions as a single inline unit, requiring flow stoppage or bypass when the basket becomes clogged with debris. The changeover time may not be long, but some processes cannot tolerate any downtime. A duplex strainer is comprised of two simplex strainers incorporated into a common housing. An inlet chamber and diverting valve selects which strainer basket will process the liquid flow, while isolating the other. Changes in pressure drop through the device can be used to signal when it is time to switch operation between the strainer sections.

Fluid filtration is an important part of keeping a process in operation, reducing wear and tear on piping system components and equipment. Share your process fluid filtration challenges and requirements of all types with application specialists. Leverage your own process knowledge and experience with their product application expertise to develop an effective solution.

Automatic Self Cleaning Strainer for Fluid Processing

An automatic self-cleaning strainer is suitable for many
applications and reduces manual maintenance.

Strainers and other filtration equipment reduce the burden of targeted unwanted solids in a fluid system. Potentially damaging particulate material is trapped and held for removal from the system. Keeping fluid systems clean helps to maintain long term design performance and potentially extends the operating life of pumps, valves, and other mechanical devices in the system.

Strainers generally consist of a heavy duty housing and a contained screen with controlled opening size designed to disallow the passage of particles exceeding a targeted size. Trapped particulates remain on the screen, or within a shape created by the screen such as a basket (see basket strainer). The continuing collection of solids will eventually impede the free flow of the process fluid, so the strainer must be emptied or cleaned periodically. The frequency of cleaning is a function of the solids content of the incoming fluid and may not necessarily be a regular interval. A simple strainer, to be cleaned, requires temporary shutdown of the flow or bypass of process fluid around the strainer assembly. A duplex strainer consists of twin strainers, usually housed in a common assembly, with a diverter valve that allows the inlet flow to be directed to one of the strainers while closing off the other from the system. This allows for cleaning of one of the strainers while the other is in active service, maintaining continuous fluid flow.

A third solution provides the continuous operation of a duplex strainer, but without the need for manual cleaning. 

An automatic self-cleaning strainer, such as the MCS 500 from Eaton provides uninterrupted operation without a duplex configuration or regular manual cleaning. It's form is essentially a housed strainer with a built-in scraper blade that moves along the inlet surface of the strainer media, moving accumulated solids to a collection chamber at the bottom of the pressure housing. Automatic controls regulate the operation of the scraper and discharge valve on the purge chamber that removes the collected solids from the system. The automatic self-cleaning strainer provides a cost effective time saving solution for the filtration of compatible fluids.

More detail for the MCS 500 is provided below. Share your fluid filtration requirements and challenges with fluid processing specialists. Leverage your own process knowledge and experience with their product application expertise to develop effective solutions.

Automatic Self-Cleaning Strainer for Process Fluids from MSJacobs-Cali