FUEL POLISHING

Without GCF Filters

With GCF Filters

Diesel fuel can easily become contaminated with microorganisms such as bacteria, fungi, yeast, mold, and to a lesser extent algae. Diesel fuel in the presence of water and nutrients makes conditions ripe for high bacterial growth. In classical microbiology, microbes will generally need water (H₂O), Carbon (C) source, nitrogen (N), phosphorus (P), sulfur (S), trace minerals, and some form of oxygen (free or bound to other atoms) to grow.  Most of these conditions are met in fuel tanks and fuel lines. Water and microbes can be introduced from the outside air or other environments. Water can also form from changes in storage temperatures, which causes condensation to occur.

“I purchased my Gulf Coast Filter System (for my Grand Banks 42 Classic) two
years ago and assembled and installed it myself  (between the supply from
the tanks and the Racors.) It's an outstanding system.....Racors stay almost
clean "as a whistle" and get changed only once a year as part of seasonal
decommissioning in the fall.“   
Name:  Robert F. Preti  (Bob) Boat: Grand Banks '42  "ZEPHYR"

Click here for photos of the Gulf Coast Filter installed on Mr. Preti’s Trawler

The Need for Fuel Polishing

The most common reason for marine diesel engines in general, and recreational trawler diesel engines in particular, to fail to run is associated with "bad diesel fuel." The things that make the diesel fuel bad generally have nothing to do with the original quality of the fuel. The problems come about because of the condition of the fuel we buy and what happens to the fuel when it gets stored, sometimes at the suppliers' facilities, but most often in our own vessels.  Pleasure boats sit idle for long periods of time allowing algae time to grow in the tank.  Most of this contamination adheres to the wall of the tanks and you might not notice a problem while running the engines at the dock.  Once the boat is underway and the fuel begins moving around the contamination tends to start breaking away from the wall of the tank and entering the fuel.  This contamination can clog your filters and shut down your engines.  Having your engines shut down from clogged fuel filters can really ruin an otherwise enjoyable outing, but it could really get bad if you have them shut down while trying to navigate in high seas or critical situations.

Fuel Polishing can help Eliminate your Fuel Problems

Gulf Coast Filters offer a Fuel Polishing Kit that once installed will be able to polish your fuel while the boat is not in use.  You can also hook this system up to polish the fuel while the engine is running.  This system uses its own independent fuel pump and continuously pulls fuel from the tank, through the filter, and back to the tank.  The GCF Fuel Filter will remove particles below 1 micron and by using this system for hours at a time can polish your fuel to a much cleaner level than standard factory filtration.

We offer Fuel Polishing Kits to fit your needs depending on your application. Our most popular kits are the GCF-FPS-DELUXE-KIT - (Recommended for vessels with over 500 Gallon Capacity) and the GCF-FPS-KIT - (Recommended for vessels with under 500 Gallon Capacity)

The GCF-FPS-DELUXE-KIT includes the following components:
1.  GCF Model F-1
2.  Oberdorfer 120 GPH Bronze Gear Pump AC or DC
3.  Marine Electrical Box
4.  Stainless Steel Liquid Vacuum Gauge
5.  12 Hour Spring Wound Mechanical Timer
6.  Pipe Stick Compound
7.  3-Way Bronze Ball Valve
8.  Electronic Water Sensor with Computer and Strobe Light
9.  (4) 1/4" X Close pipe nipples
10. (2) 1/4" pipe elbows
11. (3) 3/8" X 1/4 pipe bushings
12. (6) 3/8" X close pipe nipples
13. (2) 3/8" X 6 pipe nipples
14. (5)  3/8" Pipe elbows
15. (2)  3/8" Pipe tees
16. (3)  1/2" X 3/8 pipe bushings
17. (3)  3/8" Bronze ball valves
18. (4)  1/2" X close pipe nipples
19. (3)  1/2" Pipe elbows
20. (1)  1/2" Pipe tee
21. (1)  1/2" Pipe plug
22. (2)  1/2" Bronze ball valves
23. (1)  1/2" Bronze check valve
24. (8)  3/8"  npt X #8 JIC flare fittings
25. (8)  #8 Push-on hose fittings
26. (8 feet) #8 Aeroquip FC-332 1/2" ID  Fuel Hose

The GCF-FPS-KIT includes the following components:
1.    GCF Model F-1
2.    12-Volt Walbro Continuous -Duty Pump
3.    (4) 1/4" X Close pipe nipples
4.    (2) 1/4" pipe elbows
5.    (3) 3/8" X 1/4 pipe bushings
6.    (6) 3/8" X close pipe nipples
7.    (2) 3/8" X 6 pipe nipples
8.    (5)  3/8" Pipe elbows
9.    (2)  3/8" Pipe tees
10.  (3)  1/2" X 3/8 pipe bushings
11.  (3)  3/8" Bronze ball valves
12.  (4)  1/2" X close pipe nipples
13.  (3)  1/2" Pipe elbows
14.  (1)  1/2" Pipe tee
15.  (1)  1/2" Pipe plug
16.  (2)  1/2" Bronze ball valves
17.  (1)  1/2" Bronze check valve
18.  (8)  3/8"  npt X #8 JIC flare fittings
19.  (8)  #8 Push-on hose fittings
20.  (8 feet) #8 Aeroquip FC-332 Fuel Hose
 

Fuel Piping Basics

A basic fundamental in designing a diesel fuel system for any boat is to design the system so that the boat will not have to stop if a fuel filter gets clogged or an instrument breaks. There are many situations where not having engine power is extremely dangerous. It is so dangerous that the Rules Of The Road have a special category and rules for it, "Vessel Not Under Command." It is necessary to design the piping so that just adjusting a few valves will allow fuel to flow so the vessel can remain under command.  We recommend using Pipe Stick Compound or Loctite 242 on the pipe fittings, or any good quality plumbing sealant.

System Operation

The fuel polishing system can be used either with the engine running or not running.  It will take more time to do the plumbing, but by having the system hooked up for running would give you a back up fuel pump if your engine’s fuel pump where to ever go out during a voyage.  This will mean that you are polishing the fuel any time you are underway. If you are on a cruise that means you may not need to operate the polishing system on its weekly schedule. You can just operate on the weekly schedule when the boat is idle. In any event, you should pump enough to turn the fuel over at least three times per week. More is better than less.

Check Valve

The system is designed so that the Walbro just keeps a positive head on the engine lift pump while underway and bypass most of the fuel around the engine. If the Walbro were to fail while underway, the engine lift pump would try to draw fuel from the engine return line and the engine would stop running because of air in that line. The check valve will prevent that problem. The two-way valve in the same line can be used to close the return as well, but the check valve just makes it more convenient.

Three-Way Valve

The three-way valve is needed for those who do not want to run the Walbro underway. In that situation, turn the three-way valve to the proper position and adjust the two-way valve in the line that has the check valve.

Fuel Circuit

This is a GCF Law when using the polishing system:

Return the fuel to the same tank it came from.

Any other procedure may lead to a fuel spill. That means making sure the valves at the fuel tanks are always set properly.

Other pumping arrangements may be more efficient at cleaning up the fuel, but the risk of a fuel spill removes them from consideration.

Day Tanks

Day tanks have become a popular topic of late, and a few words are necessary about them in connection with a fuel polishing system.

The object of a day tank is to provide a "day's" quantity of fuel that is guaranteed to be clean and dry for the engine. Sometimes it is used to overcome the problem of excessive suction heads on the engine lift pump.

It is important to remember that the clean and dry fuel in the day tank will be exposed to the same conditions that cause the fuel in the main storage tank to become bad. Given enough time, the fuel in the day tank will get to the same condition as the fuel in the main tank. A filter and a water separator are still required on the outlet of the day tank.

To provide the desired results, this tank must, in fact, be a "Day Tank." That is, the fuel in this tank must remain there for only a short time. All the problems of long-time fuel storage in the main tank will be present in the day tank if fuel remains in it for long periods of time. Once it ceases to be a "Day Tank" it must be treated just like any other tank.

Wiring

All of the usual safety wiring practices should be followed and the pump should be protected with a 5-amp fuse or circuit breaker. It will be convenient to locate the switch or timer close to the helm.

The following page will show diagrams of hooking up a basic independent polishing system and also hooking up a polishing system that operates while the engine is running.  These are basic drawings, and as you know all boats have different engine room configurations.  You might need to add or take away depending on your application.

The following diagram is for using the fuel polishing system isolated so you can polish one tank of fuel at a time.  The diagram on the following page describes how to hook the system up to polish the fuel while the engine is running.

The following diagram is for using fuel polishing system while the engine is running.  This hook-up also gives the user the option of bypass the fuel polishing system while the engine is running. 

Gulf Coast Filters can custom build a fuel polishing system to fit your needs.  We can accommodate any fuel supply for engines and offer polishing systems with up to 3,000 gallons per hour flow rates.  Give us a call and we can design a system to fit your vessel’s needs.  We offer multiple tank systems, 115-volt systems, air operated systems and much more.   Since 1990, the U.S. Army National Guard has used Gulf Coast Filters to polish fuel in the M-1 Tanks.  The M-1’s also set for long periods of time giving them the same problems as the pleasure boats. Gulf Coast Filters has over 20 years of fuel cleaning experience to offer you.
Photo of GCF Fuel Polishing System for the U.S. Army National Guard The U.S. Army National Guard has 18 of these units in operation throughout the nation.