Duplex strainers remove damage-causing particulate matter from the process media and do not have to be shut down for strainer basket cleaning allowing the line to run continuously.
Both Model 950 and 900 duplex strainers feature two basket strainer housings with a valve flow diverter assembly connecting them. When one strainer basket needs to be cleaned, flow is switched to the other. The first basket is removed, cleaned and is ready for use again.
Eaton can custom-fabricate a duplex strainer to meet the requirements of specific applications. Both manual and automated operations are available.
Fabricated duplex strainers are designed to meet exact specifications in the event that a standard duplex strainer doesn’t work in any application.
Two Cover Types
Models 950 and 900 duplex strainers feature a choice of two cover types.
The simplest type is the bolted cover, which is cost-effective and works well in applications where basket changing is infrequent. A davit assembly can also be specified for larger strainers that have heavy covers. This makes it possible for a single person to remove and replace the cover of the strainer.
If the strainer is going to be opened frequently for basket cleaning, a bolted cover may be less effective because of the time needed to remove and then re-install the cover bolts.
For these applications, Eaton offers a special hinged quick opening cover that is secured by swing bolts. This type of quick opening covers can even be adapted for higher pressure applications if required.
For medium size strainers from 8" to 16", a bolted slide hinge cover can be specified. This allows a single operator to open and close the cover. Eaton can also design and manufacture special covers to meet the requirements of any application.
Unique Strainer Baskets
Eaton has designed a special, unique strainer basket for its fabricated duplex strainers. The basket has a slant top design, which improves the flow through the strainer and results in significantly lower pressure drops.
The slant top design results in a more compact basket, which weighs less than an ordinary basket and makes it possible for a single person to remove it from the strainer housing.
Strainer baskets are made of stainless steel, although almost any type of material can be specified.
Basket perforations from 1/32" up to 1" are available and mesh linings in sizes from 20 to 400 mesh for fine straining applications can be specified.
Model 950 or 900 duplex strainers are designed to meet the requirements of most duplex strainer applications. Modifications can be done easily and cost-effectively if required to suit specifications.
Fabricated duplex strainers can be designed with a backflush/ backwash option. In these designs a piping connection with an on/off backflush valve is fabricated at the strainer bottom and has a connection to the bottom of the strainer basket.
When solids accumulate in the bottom of the basket, the backflush valve is opened and the differential pressure between the operating pressure and the backflush system removes the solids without shutting the system down.
Backflushing is often supplemented by a backwashing operation. Backwashing is done by having fluid flow under pressure in the reverse direction into an empty strainer. This flow reversal backwashes the basket and removes the residual dirt. Backwashing is often regarded as a second step used to take out dirt not removed by backflushing.
Duplex strainers are available in carbon steel, stainless steel or special alloy material.