Specifications for HD Q-PAC®
Oil Water Separation Coalescing Media

Physical Data
Material: Polypropylene
Specific Surface Area: 132 ft2/ft3 (433 m2/m3)
Bulk Density: 7.5 lb/ft3 (120 kg/m3)
Void Fraction: 87%
Smallest Grid Opening: 0.16" x 0.16"
Standard Module Size: 12" x 12" x 12"
(305mm x 305mm x 305mm)
Operating Flow Rates: 1-12 gpm/ft2
(530 liter/m2-min)
Temperature Limit: 200ºF (93ºC)

U.S. Patent #5,458,817; worldwide patents pending


The oil water separator’s separation chamber shall contain HD Q-PAC® coalescing media, supplied by Coalescing Concepts, Inc., having a minimum of 132 square feet per cubic foot of effective coalescing surface. Much of the surface shall be in the form of parallel rods that can be oriented perpendicular to the horizontal or longitudinal axis of the separator, creating an angle of repose of 90° to facilitate the removal of solids that might otherwise obstruct passageways and increase velocities to the point of discharging an unacceptable effluent. The rods shall be spaced 3/16” apart for removal of at least 99.9% of free oil droplets 20 microns or greater in size. Laminar flow, with a Reynolds Number of less than 500 at maximum flow rate, shall be maintained throughout the separator packed bed including exit and entrance so as to prevent any re-entrainment of oils with the water.

Flow through the polypropylene coalescing media shall be crossflow perpendicular to the vertical media elements such that all 132 ft2/ft3 of coalescing media is available for contact with rising free oils. None of the coalescing surfaces shall be pointing upward so as not to be available for contact with the rising oil droplets in the crossflowing oily water. The media shall have a minimum of 87% void volume to facilitate removal of sludge and dirt particles as they fall off the vertical elements and settle in the sludge collection compartment of the oil water separator. The media when installed in a crossflow OWS shall meet US EPA Method 1664 Revision A and also European Standard EN 858-1 for oil water separators.