This type of basket strainer has two separate strainer basket chambers that operate independently. When one basket chamber becomes full, the flow is switched to the other allowing the first basket to be pulled out and cleaned. A duplex strainer is essentially connected with a three-way valve used to divert flow from the dirty basket chamber to the clean basket chamber.
A duplex or double basket strainer can operate continuously and never interrupt your process. Ideal for applications where pipelines cannot be shut down for basket changeout.