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Retrofitting Oil Water Separators

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Oil-water separator internals with Multi-Pack™ components, showcasing Mercer International retrofit upgrade solution.

Why Retrofitting

Transform the Separator You Have Into the Separator You Need.

Most facilities don’t have the luxury of starting from scratch.
They have concrete in the ground, steel tanks already piped in, and systems that have been “good enough” for years — until suddenly they aren’t.

Sludge is building faster.
Effluent quality is unstable.
Media is clogging.
Operators are fighting constant clean-outs.
Compliance is now a weekly worry instead of a quarterly formality.

The truth?
You probably don’t need a new separator.
You need the right internals, the right hydraulics, and a design that can actually handle the wastewater you’re treating today — not what was assumed twenty years ago.

That’s where Mercer’s retrofitting solutions come in.

Existing oil-water separator with Multi-Pack™ internals, Mercer International retrofit upgrade.

The Mercer Philosophy on Retrofitting

We don’t treat retrofits as “patch jobs.”We treat them as full system rehabilitations that deliver:

If a tank is still sound, Mercer can transform it. There are two major retrofit paths — each addressing a fundamentally different problem.

Mercer International Multi-Pack™ internals for oil-water separator retrofit, coalescer packs and distribution system upgrade.

Existing Separator Upgrades

When the Tank Is Fine, but the Internals Are Failing.

Most underperforming separators have one thing in common:The tank is structurally fine, but the coalescer, baffling, or outlet configuration has failed or was never engineered correctly in the first place.

Mercer upgrades replace:

With Mercer’s removable Multi-Pack™ media and engineered hydraulic controls, a “problem separator” becomes a high-performance system with:

Explore Existing Separator Upgrades
Mercer International Multi-Pack™ internals inside oil-water separator, showcasing upgrade components and improved separation efficiency. Mercer International Multi-Pack™ internals for oil-water separator retrofit, showcasing upgraded coalescer packs. Oil-water separator internals upgrade with Multi-Pack™ components and removable coalescer packs.

Modernizing API Tanks for Superior Performance

When a Bare API Tank Needs to Meet Modern Performance Requirements.

API separators were never designed for today’s wastewater realities:

They were built for surface area, not enhanced gravity separation.Mercer’s API Retrofit packages introduce:

The result:
A passive API basin becomes a true engineered separator — often performing at levels competitive with new factory-built systems.

Explore API Upgrades
Removable Multi-Pack™ internals for oil-water separator retrofit, demonstrating Mercer International’s upgrade solutions. Oil-water separator internals with Multi-Pack™ components, showcasing Mercer International retrofit upgrade solution. Mercer’s Multi-Pack™ removable coalescer media for oil-water separator upgrades and API compliance.

Why Retrofitting Works So Well

Because 90% of separator failures come from design and internals — not the tank.

Most customers don’t need:

They need:

That is where Mercer out-engineers everyone else.

Mercer Retrofit Advantages

The Highest ROI Path Most Plants Never Realized They Had.

You get nearly all the benefits of a new separator without the new separator price.

When to Consider a Retrofit

Mercer retrofitting is the right choice when:

If the tank can physically hold water, Mercer can usually transform it.

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