You get what you pay for, and most times much less. Below is an excerpt from a virtual trade show where lead design engineer Dave Goding discusses the fouling problems that are guaranteed to occur when using honeycomb/egg-carton plastic coalescer designs:

Once inexpensive corrugated plastic media took over as the “standard” in oil/water separator design, it became a race by manufactures to produce separators with low price as their selling feature. Now the oil/water separator industry was selling their equipment on price instead of features & benefits. Once price became the main selling function, many long-standing internal components and sound design standards began to be cheapened or eliminated. By designing down the coalescer, the inlet and outlet baffles, solids handling capacities, etc., manufactures began sacrificing functionality and efficiency. This drastically reduced the end user’s ability to stay in compliance.

Manufactures tightly pack these plastic bundles in separator units, selling promises of higher surface area and (theoretically) better oil removal capabilities.

The “nooks and crannies” within these coalescers are the problem with this design. The various nooks, crannies, ridges and flat spots cause solids to lodge in and on the plates, building up and fouling the packs prematurely. Further, there is no clear path for solids particles to make their way out of the coalescer. The settling solids have nowhere to go and “dead end” within the coalescer causing even more rapid fouling.

To further complicate the problem with this design, these style coalescers are nearly impossible to clean. Because of their design, high-pressure washers can only penetrate from 6”-12” into the packs before the velocity is dissipated.

The cleaning becomes very labor intensive. Many times the packs cannot be cleaned all the way through, therefore the end user is forced to throw away these packs after a few cleanings and replace them with new ones. In certain more high-solids applications or applications with “sticky” oils and solids, this could entail a full coalescer replacement every time maintenance is performed.