FF-250 Series Coalescing Filters

FF-250™ Series Coalescing Filters


Further Information:

The FF-Series coalescing filters from Perma Pure are high efficiency particulate and coalescing filters designed for high temperature corrosive service. Used as a coalescer, this filter removes liquid droplets and particles down to 0.1 micron with an efficiency of 95% or greater. The thick, high capacity borosilicate glass and Teflon filter element uniformly drains coalesced liquids to the bottom of the housing, where they are evacuated through the 1/8″ NPT drain port. For particulates, the filter removes 95% of all particles 0.1 micron or greater, with a low pressure drop and long element life.

Coalescing filtration is achieved by forcing the gas stream through the filter element (see illustration). The flow path shown reflects a coalescing application. In this situation, small aerosol particles are forced together as they pass through the fine inner layer of the filter element. The larger drops created in this process fall out of the gas stream due to their mass. This natural separation is assisted by the coarse drain layer on the outside of the filter element. In a particulate application, this filter can be installed to reverse the flow path shown. The captured particulate then collects on the outside surface of the element, permitting visual determination of element condition.

FF-250 Series Coalescing Filter Specifications

Model Number FF-250-SG-2.5G FF-250-FG-2.5G FF-250-SS-2.5G
Housing Material Stainless Steel Teflon Stainless Steel
Shell Material Glass Glass Stainless Steel
Element (FF-250-E-2.5G)

Borosilicate glass w/Teflon Binder with 1µm absolute porosity, 0.1 µm 99.3% removal

Maximum Temperature 120 °C 120 °C 230 °C
Maximum Pressure

30 psig

Inlet /Outlet and Drain Port

1/8” FNPT

O-ring (FF-250-3)

Viton – 3 per unit

Shell Volume

200 cc

250pressure line.GIF

FF-250 Series Filter Maintenance Items

ITEM # Description
FF-250-E-2.5G 2″ Teflon & glass replacement element only
FF-250-3 Replacement O-rings, set of 3

FF-250 Series Filter Maintenance Procedure

All coalescing/ particulate filters should be checked regularly to ensure that the element is in good condition. The element should be replaced if it appears to be dirty or begins to cause a flow restriction in the system.

  1. Loosen the bolt on the bottom of the filter housing.
  2. Pull the assembly apart gently and remove the filter element.
  3. Install the glass shell on the bottom piece.
  4. Place the new element into the grooves in the top and bottom of the housing. Make sure that the element is seated correctly and parallel to the glass shell.
  5. Inspect the o-rings on the top and bottom pieces and on the center bolt.
  6. Carefully mate the bottom assembly onto the top piece. A slight twisting motion may be required to allow the shell to slip over the o-ring seal.
  7. Visually make sure that the element is seated correctly in the top groove.
  8. Replace the bolt through the hole in the bottom piece and screw clockwise into the tip piece. Be careful not to over-tighten the center bolt. It should be just tight enough as to not vibrate loose. Over-tightening will not help the filter to seal and will not increase performance. It may cause the glass shell to crack or cause other damage.
1 Top
2 Element
3 O-Ring
4 Shell
5 Bottom
6 O-Ring
7 Thumbscrew