Oil Water Separator Filter: The Ultimate Guide

Do you know choosing the right oil water separator filter will help you to separate oil from water particles?

You can efficiently reduce the oil to levels of about 100 ppm.

The best part?

Today’s guide will walk you through everything you need to know about oil water separators.

Whether you’re new or an expert in the industry, you’ll find this guide quite useful.

Let me take you through every stage…

What is an Oil Water Separator Filter?

According to Corrosionpedia, an OWS is a vessel that plays the dissolution role in fluids bearing different densities.

The petroleum and water treatment industries, as well as the HVAC systems, employ the various separators in their daily operations.

It consists of three major parts-the oil separator unit, filter unit, and the oil content monitor and control unit.

Basically, the filter stage, coalesce stage and the collecting chamber form the three major stages of the filter unit.

It’s starting to get a little bit complex, right?

There is no cause for alarm; this is what I’m referring to.

Oil water separator

Oil water separator filter Image courtesy YNTCo. Ltd.[inoco]

You will discover that most of the Oil water separators differ in terms of design.

However, the operating principle is almost similar.

Watch this video to understand the concept better.

As you progress, you will understand the crucial role the oil water separators play in many industries around the globe.

Remember, an ideal OWS effectively and efficiently separates oil from bilge before it gets discharged.

This equipment functions in line with Stokes law and makes a difference by separating two components.

Usually, it utilizes the difference in the specific gravities of the components in question.

You will also realize that the application requirements greatly dictate the configuration and design of the OWS.

The Oil water separator filters pull along with both advantages and disadvantages and I will take you through both.

Advantages and Disadvantages of Oil Water Separator Filter

The following are the main advantages of the Oil Water Separator Filters

  • Bears more advanced properties than the traditional means of separation. This means more effective and efficient separation surpassing that of the traditional coalescing media.
  • Helps with water preservation and the cutting down on the lake bills
  • Minimizes environmental pollution
  • Makes it possible to save cash
  • Preservation of aquatic life in the coastal waters

On the other hand, oil water separators have the following disadvantages:

  • Relatively high maintenance costs
  • Requires expert knowledge to operate

Types of Oil Water Separators

Whenever you are looking for oil water separators, you can consider any of the following:

· Parallel plate separators

The good thing about the parallel plate separators is their efficiency in the removal of oil from water.

These plates suspend the oil droplets out of the hydraulic flow path and as a result simplifying the extraction process.

By increasing the surface area, you get to get to improve the efficiency in separation.

Remember, efficiency in the oil water separation exploits Stoke’s law.

Stokes law

Stokes law

Also, remember to ensure that your separators conform to the most ideal design criteria.

For instance, it must be in line with the laminar flow condition

Utilizing the coalescing surface area of the plate pack the best way guarantees you outstanding results.

Check out the figure below to get an overview of the parallel plate separators

Parallel plate separators

Parallel plate separators

· Conventional separators (API)

This one relies upon the gravity differential principle to undertake the oil/water separation exercise.

Under this, you need to be full conversant with several factors that determine the efficiency in separation.

These include the size of the oil globules, viscosity, and temperature.

The other one is the specific gravity of oil and wastewater.

This system comprises an inlet section, an oil retention baffle, a separators channel among others.

Sounds complex?

No cause for worry!

Check this one out.

Convectional plate separators

Conventional plate separators

Understand that top manufacturer develop the above ground separators using carbon steel.

This usually bears the corrosion resistant coatings.

On the other hand, they resort to them to steel or concrete in developing the below ground separators.

· Simplex-Turbulo oil/water separator

One outstanding attribute you will discover about this separator is its great capabilities in breaking up emulsions.

With it, you achieve an optimum balance in terms of the capital costs, function and above all the maintenance costs.

One of its most outstanding features is the two-stage turbulo mechanical phase breaker.

The two make it easy for you to efficiently and effectively process high oil concentrations without major pressure losses.

Remember that these are quite easy to install and require rather minimal space requirements.

Asides from that, the operation is automatic and you will also appreciate the compact dimensions.

Have a look at the image below

Simplex turbulo

Simplex –turbulo Image courtesy simplex-turbulo.com

· Hydrocyclone stems

As mentioned earlier, the different separators resemble each other somehow in terms of the operational principle.

However, you need to distinguish this separator by the fact that it usually applies extreme centrifugal force.

It does this in a bid to separate the particles of oil from the wastewater.

But how do you get to distinguish it from the rest?

It is simple.

It bears a conical-shaped chamber which has two exit channels on both ends not forgetting the wastewater inflow inlet.

The wastewater moves into the chamber.

After that, a centrifugal force that is up to 100 times that of gravity spans it vigorously.

Eventually, the heavier wastewater gets pushed to the chamber’s outer wall.

The narrow conical end bears an outlet through which the water gets discharged.

On the other hand, the lighter oil phase moves to the central point of the cyclone chamber.

From there, pressure forces it upwards eventually getting discharged via the outlet at the top.

Look at the image below


Hydrocyclone Image courtesy cleanswater.com

This equipment pulls along with several disadvantages.

One of them is its higher capacity that allows flow rates of up to 500,000 liters or even more.

The other advantage is that you are able to eliminate oil droplets ranging between 10-15 microns.

This is way much bigger than what the traditional separator achieves.

The maintenance costs are at a minimum.

The perfect explanation is that it lacks the moving parts.

· Coalescing

The coalescing separators employ the gravity principle to undertake the oil/water separation exercise.

If you want to give a boost to the coalescing performance, you will need to insert an additional coalesce filter.

Making this move will also help you improve draining values.

The filter is cylindrical in shape and that has a positive impact on the flow in the separator.

Take a look at this


Coalescing separator filter Image courtesy resrachgate.net

It bears a simple design that facilitates efficient and effective removal of oil and wastewater.

You will appreciate it more if you operate a medium enterprise since you will easily conform to environmental compliance.

Regardless of the size of your business or budget, there is something for everyone.

· Vertical gravity separator

You definitely wish to own a separator that outperforms the traditional oil separators.

With the vertical gravity separator, you remove oils from water rather efficiently.

Basically, it is a much better experience compared to the traditional oil water separators.

Remember that making purchases from a trusted provider guarantees you longer service.

Asides from that, you maintain keep the maintenance costs low.

The commercial kitchens, mining workshops, and the service station rely heavily on these kinds of separators.

Here is an overview of the Vertical gravity separator

Vertical separator

Vertical gravity separators. Image courtesy cleanwater.com.au

How to Tap Oil in Water Oil Separator Filters

Now, even before we delve deeper into this, you can watch this short video.

To succeed at separating the maximum amount of oil particles from water, you will need to acquire a top-notch separator.

As a matter of fact, getting value means extracting about 15 parts per million of oil from the system.

Oil and water happen to have different densities.

It is this variation in densities that help you separate the two.

Usually, the oil settles on the surface whereas the water stays at the bottom.

Some of the factors that come into play determine ease of separation includes the filters, baffles and the heating coils.

Always remember that gravity differential surpasses the test when it comes to the separation principle.

Greater gravity differential means more ease of separation.

Also, it is worth noting that the oil globules are of different sizes.

As a matter of fact, larger globules and elevated temperatures mean a higher separation rate.

You need to avoid the chances of agitation at all costs since it results in mixing of the two.

Agitation normally results in water and oil mix.

And also get to understand the huge role of the laminar flow.

This together with the heating coils help you achieve desirable results.

Above all, you require the angled surfaces and that is where oil basically accumulates resulting in the formation of globules.

You then witness the suspension of the oil globules at the top.

The video above shows the movement, channels, and the valves that aid in the separation of oil from the water.

Next, we have to look at the separation principle in an in-depth manner so that you become a guru.

Oil Water Separator Design System and Working Principle

Oil water separators get constructed in such a way that they effetely prevent oil discharge in ships.

Oil water separator

Oil water separator

Ships carry them on board since they prevent oil discharge in the process of pumping out bilges.

With the above points in mind, it is now time to take a look at the three main segments of the OWS.

You need to practice with the equipment adequately and also be well conversant with the operational manual.

The port state inspections asses them to ensure they are in good working condition.

· Oil Separator unit

This unit consists of multiple catch plates fitted inside the oil collecting chamber and the separating compartment.

Oil is less dense than water and that causes the oil to rise onto the collection compartment.

Next, the non-flowing mixture of oil passes through the catch plates to sit on the settling compartment.

After a short while, the oil segregates eventually collecting in the collecting chamber.

The designated OWS sludge tank is the one that receives the oil coming from the control valve.

To make the unit more efficient, manufacturers fit them with heaters

With this, it gets easier to achieve a smoother flow as well as separate oil from water.

Fundamentally, this first stage eliminates most of the physical impurities.

The importance of this stage is that you attain fine filtration.

· Filter unit

Basically, the input of this segment is the discharge from the first unit.

Under this unit, you get the filter stage, the coalescer and eventually the collection chamber.

The filter removes particles and other impurities which eventually settle at the bottom before elimination.

It is the coalescence process that causes the oil droplets to link up and they get bigger as a result.

The coalescer functions by shredding the surface tension that exists between the mixture and the oil droplets.

The bigger oil molecules settle on the surface and get removed from the collecting chamber.

The fresh water inlet fitted at the filter unit helps with the cleanup exercise.

· Oil content and monitoring segment/unit

This unit bears the monitoring and the controlling units that work in unison.

The Oil Content Monitoring Unit helps you monitor the ppm of oil efficiently and effectively.

Basically, a high ppm sparks the alarm and the control unit eventually receives the data.

The control unit checks out OCM’s output signal and the alarm determines what happens next.

Remember that an alarm means that the water won’t move overboard through the 3-way solenoid valve.

The control unit is the one that usually commands the 3 solenoid valves.

You should be well-conversant with the fact that it is the OWS discharge that bears the 3-way valve inlet.

One of them is from the OWS sludge tank whereas the other one is to the overboard section.

The sounding of the alarm from the OCM results in the 3-way valve discharging the oil mixture.

That moves directly into the sludge tank.

You will require a small pipe to assist with the flushing exercise of the OCM unit.

A chief engineer is the person best fit to operate the OWS system.

An Outlook at a Shipboard Oily Water Separator Sketch

First and foremost, you will have to fill the whole unit with clean water.

From there, the oil/water progresses to the coarse separating compartment.

The heating coil plays an important role in helping oil rise to the top surface.

But even with that said, remember the lower oil density is the major reason it floats to the surface.

A sensor ion a good working condition detects the oil level.

From there, the oil gets transferred to the dirty oil tank and of course, it bypasses the oil valve.

The fine separation compartment receives the remaining oil/water traveling downwards.

These contents move through the catch plates.

Note that more oil gets separated on the lower side of the catch plates.

What moves to the 2nd stage is water with quite minimal amounts of oil.

It is now time for the two coalescer filters to eliminate the physical impurities present.

Finer filtration takes place at this particular point.

The special role of the coalescer filter helps a huge deal in the collection of clean water.

We thus end up with refined and clean water in the collecting tank.

Sketch of ship oil water separator

Sketch of a ship oil water separator Image courtecymarinerspotted.com

Effects of Oil Temperature and Density in Oil Water Separator Filters

There exists a rather close link between the temperature and density of oil with the ease of its separation.

An elevation in temperature by any given margin acts on the viscosity of the oil.

Actually, it reduces its viscosity in a relative way and thus making the separation easier.

It is pretty simple to understand and I hope you get it straight this time around.

Any increase in temperature reduces the density of the oil and that is exactly how you achieve better separation.

As a rule of the thumb, those in charge of ships must ensure minimal discharge of oil in seawater.

The responsible authorities charge heavy fines to those that do not adhere to rules.

But you shouldn’t get it wrong-itis about safeguarding aquatic life.

At all times, ensure proper installation of the oil/water separators and maintenance as well.

Key Features of Oil Water Separators

Even before we proceed, let me emphasize that ensuring all the key features work correctly is critical.

The Oil Water separators comprise of several parts- each designed to play a special role in the entire separation exercise.

Let’s begin with the oil water separator sensor.

As the name suggests, it gives real-time feedback to the system.

The automatic tank gauge receives the feedback.

The next step follows the status of the product threshold registers.

Remember that a properly working water separator tank means efficiency and effectiveness.

Also, note that ideal equipment is the one that withstands the harshest of conditions.

What do I mean by that?

Simple, you require an oil water separator manufactured using the industrial grade material.

That is how you get to feel secure even in the harshest environments.

The control unit is the section that commands some three solenoid valves in the system.

A small pipe connection plays a vital role in moving in fresh water that helps with the flushing.

Second, let’s check out the separator unit.

It is a unit that has several catch plates which lies inside the collecting chamber.

This unit needs to function optimally and that best explains the incorporation of the heater which boosts efficiency.

It enables you to move the separated oil into the designated OWS.

Third is the filter unit and this is where you discover the coalescer.

After separation, the particle moves to the bottom where the removal exercise swings into effect.

It is in the collecting chamber that the final separation takes place.

To summarize this section, I will break it down to some three major features.

  • There is a partitioned inlet that bars solid particles entry into the filtration unit.
  • The vertical plate separators
  • The oil pumping section

Applications of Oil Water Separators

Oil water separator plays an important role in many industries.

Some of the most common industries include:

Oil platform

Oil platform

  1. Process water treatment
  2. Biodiesel processing
  3. Groundwater remediation with DNAPL/LNAPL
  4. Crude oil production
  5. Process fluids reuse recovery and reuse
  6. Refineries
  7. Transformer facilities
  8. Spill recovery
  9. Liquid bulk storage terminals
  10. Transportation
  11. Stormwater runoff-commercial and industrial
  12. Food processing and rendering plants
  13. Liquid bulk storage terminals


As you can see, this elaborate guide enlightens you everything you need to know regarding the oil water separators.

So, it is crucial to remember much of what you learned here when you move out there buy the equipment.

More importantly, identify a leading and trusted manufacturer.

With such, you will never go wrong or regret.

It is a way to pay for value and also achieve the most desirable results despite the fact that scams are on the rise.

In case you need to ask any questions, please contact us.

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