Mercer International logo representing oil water separator services and technology in Albany, NY. design center

Existing Separator Upgrades

Your separator might not be the problem.
Your coalescer is.

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Crane lowering coalescing plate pack sections into an open oil water separator basin

Why Retrofitting

Revitalize Your Separator: Upgrade Internals, Not the System

Most industrial separators structurally outlive their internals by decades. The tank is still sound. The concrete is still good. The piping still works. But the coalescer packs, baffles, and distribution systems have long since failed—either through design, fouling, poor maintenance access, or media that was never meant for real-world solids loading.

You don’t need a new separator.
You need a new heart for the separator you already own.

Mercer specializes in transforming “good enough” boxes into high-performance systems by replacing only the failed elements with precisely engineered, removable Multi-Pack™ internals that restore performance, reduce maintenance, and extend system life another 20–30 years.

Aerial view of two rectangular oil water separators with walkways and piping

Why Existing Systems Fail (and Why That’s Not Your Fault)

Most OEMs built systems that look like separators on paper but:

Operators end up fighting a tank that never had a chance. A Mercer upgrade fixes that permanently.

Coalescing plate packs installed inside an open oil water separator chamber with a ladder

What We Replace (and Why It Matters)

Mercer’s Multi-Pack™ removable coalescer media for oil-water separator upgrades and API compliance.

The Coalescer (The Heart of the Separator)

We pull out the old, clogged, uncleanable block media and replace it with:

If you’ve ever tried to pressure wash into the center of a plastic block, you already know why this matters.


Inlet/Outlet Distribution

We correct hydraulic chaos by adding engineered inlet baffling that:

Poor inlet design is the #1 performance killer in older separators.

Opened steel oil water separator tank during inspection with coalescing plate packs submerged in murky water

Crews lowering a perforated baffle plate into an oil water separator during an upgrade

Automate Oil Removal

After getting the oil up we get it out:


Sludge & Solids Management

Mercer designs for solids reality, not solids denial.
We support:

Crane lifting a stainless coalescing plate pack while a worker guides it inside a plant

Crews lowering a perforated baffle plate into an oil water separator during an upgrade

Access Upgrades

If the system requires confined space entry or makes maintenance impossible, we solve that with:

Your operators should never “dread the tank” again.

What You Get After a Mercer Upgrade

And yes—many customers upgrade during bypass while their system is offline for cleaning or repair.
What starts as “just swap the media” usually transforms into:
“How fast can I get a full Mercer package installed?”

Ideal Candidates for Existing Separator Upgrades

Truck mounted oil water separator with access stairs and an onboard generator

Proof of Performance Available

You don’t have to guess.
We can pilot a Mercer system in your wastewater to show exactly what improvement to expect before committing to a full upgrade.If the pilot doesn’t work, you owe nothing.

Retrofit + Test for Free, Then We Guarantee

Mercer can pilot the exact configuration in your wastewater under your flow and solids conditions.

If it works, you know the upgrade will succeed.

If it doesn’t, you won’t waste a dollar on a retrofit that won’t solve your problem.

Zero guesswork.
Zero risk.
Maximum confidence.

Let’s talk