Plastic bag filter housings are typically used for applications requiring the removal of fine particles, in the 1 to
200 micron nominal 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 16" (#1) or 32" (#2).
We also offer
adapters enabling you to use filter cartridges in lieu
of filter bags for finer retentions.
Although filter bags are available with coarse retentions (up to 800 microns), it is more common to use pipeline strainers for retention of particles >200 microns using a perforated or mesh lined basket unless the volume of solids to remove necessitates a larger open area straining ratio afforded by a bag filter housing.
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 bag filter housings 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 material.
Similar to the Hayward SB/DB styles of plastic pipeline strainers, the FLV has a thoughtful, user-friendly design. The "rabbit ear" style chamber cover enables quick removal and access to the filter bag without requiring tools and reduces the potential for over tightening. The filter vessel body has 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 filling and it si protected from damage by the filter chamber cover handles.
Whether GFPP, PVC or CPVC, the body has two inlet ports and two outlet ports to provide flexibility for installation. Thus these filter bag vessels 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 "loop" using the upper and lower ports on the same side of the vessel. As an example, the "loop" configuration is useful if installed in a corner. GFPP material has additional ports at 90°, adding another potential inlet/outlet flow path. Unused ports are capped-off with blank true-union connections.
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 either EPDM or FKM.
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 filter 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.