There’s nothing like the wind in your hair and the sun on your face as you tool around the lake or sea in your boat. If boating is your way to get away, you’re in good company as almost 12 million boats are registered in the US.
But to keep your boat chugging along efficiently and for as many years as possible, you need to invest in proper maintenance and equipment setup. A key component of that setup is a marine fuel water separator, which protects your engine from pollutants in the fuel.
Fuel can end up with debris and water that need to be removed before it’s used. Your separator gets your fuel as clean as possible so contaminants don’t cause engine failure.
But just how does it work? And maybe you’ve been wondering — do I need a marine fuel water separator at all? Let’s take a look at this little device and what it does.
What Is a Fuel Water Separator?
A fuel water separator for boats is a small device fitted into the fuel system that ensures the fuel going to the engine is free of contaminants and water. You’ll find them on engines of all types, but they’re especially important in a marine environment where there are more chances for water to get where it’s not wanted.
If you have a newer boat, it might come as standard equipment, but it’s a simple enough job to add it to an older boat that might not have one yet.
Why Do You Need To Separate Water Anyway?
Boat motors are meant to be around water, so surely getting some water in them isn’t a big deal, right?
Water in the fuel can cause irreversible damage to the engine. If you discover you have a water contamination and you don’t have a separator, you’ll have to get a professional to drain the tank and dispose of the fuel.
Like water just about anywhere, water in your fuel can cause rust to develop on parts and loss of lubrication on injector components. You end up with surface pitting, fuel pressure loss, and poor engine performance.
Other possible consequences include the development of grime in the fuel tank and the growth of bacteria and fungus. All the gunk makes the engine work hard, and eventually, it’s not going to start.
Just how does water get into the tank in the first place? One way is incorrectly located fuel tank breathers and tank fillers. That one you can do something about to keep water out.
But the other two common ways are out of your control, thus the need for a separator. These include the development of condensation and purchasing already contaminated fuel.
The biggest risk is from condensation forming in the tank. During the day, the air is warm, and air in the tank is being forced out. At night, the air cools down and is drawn back into the tank, bringing moisture vapor that turns to liquid as it cools.
How Does a Fuel Water Separator Work?
In an engine, the gas or diesel is pulled from the tank into the engine by the fuel pump. The boat fuel water separator is placed on the inlet side of the fuel line.
The filtration process operates based on some fairly simple science. Because water is heavier or denser than fuel, it’s easy to separate through centrifugal force or gravity.
Fuel is drawn into the separator on its way to the engine. It goes through one chamber with a centrifuge, which spins the fuel so the denser water is separated. The water then drops down to the inspection or collectionbowl at the bottom.
The fuel then goes through a pleated paper filter, which removes any tiny bits of water that might remain along with other particles and debris.
The filter cartridge should be cleaned or replaced during regularly scheduled maintenance.
Choosing a Marine Fuel Water Separator
How do you pick the best fuel water separator for your boat? There are a lot of variations out there to meet specific requirements such as higher pressure fuel pumps or biodiesel fuels. And some separators like this product allow you to configure your components.
The main thing you need to look at in picking a separator is the fuel flow rate, which is not the same as fuel consumption. Flow is how much fuel has to move through the system for it to work properly. You want to ensure you get the correct size filter and specs for your particular engine.
Related to that is engine size. A bigger engine needs a bigger separator, and conversely, a smaller engine needs a smaller one.
The environment where you do your boating also plays a role in choosing a device. If you’re in a really mild climate and only have moderate usage levels, it’s not quite as important to have a super efficient one mounted. But if you’re on a lake with a lot of debris or in a high humidity climate, it’s important to have one that can keep up with the potentially higher contamination levels.
You’ll find variations in the type of filter elements as well. Most marine systems will use 10-micron and 30-micron filters. The 10-micron is most common and meets the needs of most boat engines.
The inspection bowl where the water collects can be made from clear plastic, aluminum, or some combination. If you’re good about regularly checking and emptying the bowl, a solid metal one is fine. If you need the visual cue to empty it, make sure there are at least some see-through parts.
Protect Your Boat Engine
Nothing can ruin your day of fun on the water like finding out your tank has too much water in it. A marine fuel water separator protects you from damage to the engine as well as ensures your boat is ready to hit the waves whenever you are.
Check out our other articles with safety tips and maintenance how-tos for your boat.
