Model DB Duplex Strainers made
of PVC, CPVC and Clear Eastar®
duplex strainers are used for continuous removal of
particulate from liquids or environments that are
aggressive to alloy strainers and are designed to be
installed within non-alloy piping systems.
strainers are used in applications where the flow
cannot be interrupted to clean or replace the
strainer basket. The DB series duplex
strainers consist of a pair of SB series simplex
strainers connected with a pair of linked 3-way
valves. The valve assembly diverts the flow
from the dirty basket chamber to the clean basket
chamber, isolating the dirty basket chamber so that
it can be accessed safely for cleaning or replacing
the dirty strainer basket. We've written an
BASKET STRAINERS: Differences between Simplex and Duplex
Style Strainers explaining the key differences between
simplex and duplex strainers;
since these consist of two SB series simplex
strainers, reading the overview of
plastic simplex strainers will be helpful
duplex strainers are available in
materials with the three-way flow diverting valves
matching the strainer body material; with exception
of the Clear Eastar material where PVC valves are
used. The three-way valves used are the TW
series as described at our valve website:
Three Way Ball Valves.
Both the strainer and valve connections feature the
true-union design, simplifying installation and
elastomers are used for the chamber covers,
connections and valve seals.
The standard strainer screen has 1/32" perforations
made from the same material as the strainer body.
Additional perforations are available and may be
substituted for no additional cost. it is also
possible to order stainless steel screens and mesh
lined screens for an additional cost.
One frequently asked question is:
strainers schedule 40 or 80? The answer
is "neither" because that terminology
is used to describe the uniform wall thickness of piping
and since these are molded products having varying wall
thicknesses, they cannot have a specific "schedule"
assigned to them. What you need to refer to is the rated
pressure by temperature chart to make sure that your
application falls within the limits of the strainer
material chosen. Each duplex strainer page has links to
the catalog pages and the pressure/temperature charts.
Other significant aspects to consider include:
If you intend to install a
plastic strainer within an alloy piping system it is
recommended that you install at least 10 pipe diameters
of plastic piping upstream and downstream of the
strainer to help account for differences in thermal
expansion rates of metal and plastic, transmittal of
pipe vibration and pipe loading forces. Connecting
plastic strainers directly with metal piping can
potentially damage the strainer.
Never use plastic strainers for compressible
fluids such as air or nitrogen.
||The maximum fluid velocity should not exceed 5-8
FPS and our sizing calculators
use 5 FPS as the design standard.
||Your piping system should be independently
supported; the strainer is not designed to support
piping nor should piping support the strainer.
The strainer should be mounted to a firm surface
and the piping upstream and downstream of the
strainer should be independently supported.
It's critical to review your pressure
limitations for your fluid temperature
and reduce potential
situation accordingly. |
When in-doubt, simply call us or better yet,
fill-out our application based inquiry form and
we'll assist you with the proper selection.