Bag Filter Housings made of PVC, CPVC and GFPP
Plastic bag filter housings are typically used for applications requiring the removal of very fine particles, in the 1 to 100 micron range. We offer plastic bag filter housings which are compatible with
industry standard #1 and #2 size filter bags which have a 7” diameter opening
and a filter bag length of 17" (#1) or 32" (#2).
Although filter bags are available with coarse
retentions (up to 800 microns), it is more common to use
pipeline strainers with either perforated or mesh
lined baskets for those application unless the volume of
particulate to be retained or materials of construction
lend themselves to a bag filter housing design due to
their a larger straining element and can be supplied in
100% non-alloy materials.
The Platinum Glass-Filled Polypropylene (GFPP) model is
a one-piece molded vessel having numerous locations for
true-union connections; these connections can also be
made from GFPP, PVC or CPVC. The sizes
(from 1¼" to 4") and the connection types
(FNPT/threaded, flanged and socket) are available in all
materials. "Glass Filled" polypropylene contain
glass fibers which increases stiffness and surface
hardness, thus supporting use at higher pressures and
temperatures when compared to "regular" polypropylene.
The PVC and CPVC versions consist of a common upper and
lower half, with a "spacer pipe" inserted between these
two pieces to form the "body", thus a longer pipe
is used for the #2 size and a shorter one for the #1
size; the end connection material matches the body
Similar to the SB/DB styles of
pipeline strainers, the FLV has a
thoughtful, user-friendly design. It's "rabbit
ear" style chamber cover enables quick removal and
access to the filter bag within without requiring tools.
This style cover also
reduces the potential for over tightening. The
bodies buttress style threads for the chamber cover
provide a downwards oriented failure path, so in the
event of over-pressurization the failure mode should be
predictable and protect other system components from
damage. The chamber cover also has a conical
shaped displacement geometry which serves two purposes,
it reduces the volume of the chamber when accessing the
filter bags and helps seal the filter bag in-place via
downwards pressure onto the filter bag sealing ring. The
included vent port valve is easily opened to bleed air from the system during
Whether GFPP, PVC or CPVC, the body has two inlet ports
and two outlet ports to provide flexibility for
installation. Thus they can be installed inline
(inlet and outlet are 180° apart - directly opposite
of each other with high port the inlet and the low one
the outlet) or "offline" using the upper and lower ports
on the same side of the vessel. As an example, the
"offline" configuration is useful if installed in a
corner. The GFPP material has additional ports at 90°,
adding another potential inlet/outlet flow path.
Unused ports are capped-off with blank true-union
The true-union connection design simplifies installation
as well as enabling filter housing replacement without cutting
and replacing piping; perhaps especially useful for
socket glued piping connections.
There is a restrainer basket within the filter bag
housing whose purpose is to support the filter bag,
without support clogged filter bags might rip apart due
to the weight of retained material. The o-ring seal
ensures no fluid bypasses the filter bag. There are two
configurations for the restrainer basket, one is simply
a cylindrical basket and the other has a "clamshell"
design, enabling the user to split the basket open,
which is helpful removing very full filter bags and for
installing new bags, especially the #2 size which are a
little longer than most arms and insertion can be done
without placing your hand/arm into the vessel which
might contain an aggressive process fluid. The
restrainer baskets are made from the same material as
the housing and can also be provided in 316SS for higher
differential pressure applications characteristic of
viscous fluids and high percentages of solids.
The only elastomers used are captured o-rings for the
chamber cover, restrainer basket, true-union connections and o-rings for
the vent valve; the o-ring materials are
Other significant aspects to consider include:
Never use plastic bag filters for
compressible fluids such as air or nitrogen.
• The maximum flow rate per housing is 100 GPM
for single length (#1 size) and 150 GPM for
double length (#2 size).
|Your piping system should be independently
supported; the filer housing is not designed to
support piping nor should piping support the
filter housing. The filter housing should
be mounted to a firm surface and the piping
upstream and downstream of the strainer should
be independently supported.
|It is critical to review your pressure
limitations for your fluid temperature and
reduce the potential for a
Water Hammer 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.