The PO installed an electric fuel pump. I have a backup. I am thinking of creating a fuel polishing system by installing one of these switching valves between the tank and the two parallel racors/pumps. One filter/pump feeds the engine; the other would feed a loop back to the tank. The valve is designed to serve 2 tanks and one outlet. I want to reverse that: One tank feeding 2 outlets. Near as I can tell, the switch defaults to closing one of the pair of nipples. When energized, the default is closed and the other opened. Question is whether there is any kind of anti-siphon mechanism in there that would prevent reversing the direction of the fuel flow?
Does It Know Which Way the Fuel Flows?
- Thread starter wufibugs
- Start date
I can't speak to the specific solenoid/valve you've pictured, but I can say that valves of this type typically are just valves and any back-flow prevention, etc. is handled by a separate unit. The spring strength and the seal type (o-ring?) will determine the limits of pressure and leakage. Assuming you don't deadhead the flow, you shouldn't have any problems.
On a side note, I'm curious about your reasons for doing this. If you are having problems with contamination clogging your fuel filter, I'd address the cause. (After flushing the tank for general dirt, any rust problems can be addressed with Cream Coat. If it's too far gone for that to work, you may be looking at a tank replacement.) With other fuel applications, I've doubled up on filters: a coarse, cleanable, inspectable (glass housing) filter to get the chunks and a fine paper element filter that gets changed annually. Water is treated with methanol.
I'm just curious- I'll update my thinking if there's a marine specific issue I'm ignorant of!
On a side note, I'm curious about your reasons for doing this. If you are having problems with contamination clogging your fuel filter, I'd address the cause. (After flushing the tank for general dirt, any rust problems can be addressed with Cream Coat. If it's too far gone for that to work, you may be looking at a tank replacement.) With other fuel applications, I've doubled up on filters: a coarse, cleanable, inspectable (glass housing) filter to get the chunks and a fine paper element filter that gets changed annually. Water is treated with methanol.
I'm just curious- I'll update my thinking if there's a marine specific issue I'm ignorant of!
an issue you need to check is if, when energized, and the tank is being polished does the unit allow leakage, internal, of the engine side of the circuit resulting in an air bubble getting into the injection pump. This would probably only be a "first time" issue and once all the air is out not a problem. I'm thinking a good priming of the polishing circuit followed by priming the injector pump circuit would be the answer.
Rocket: I'm planning on cleaning the tank, but as I begin cruising farther into Mexico, I want to have a means of cleaning the diesel I might get there [though I realize my existing racor should do a pretty good job]
Bill: Wouldn't any leakage resulting from an incomplete seal on the engine delivery side be fuel, not air? I'd really be concerned if the system was not closed and was allowing air into either side. I would think that with the electric pump, air bleeding should be less of a problem and way less hassle than the mechanical pump [which I will probably test and add back as a loss of electric power failsafe]
Bill: Wouldn't any leakage resulting from an incomplete seal on the engine delivery side be fuel, not air? I'd really be concerned if the system was not closed and was allowing air into either side. I would think that with the electric pump, air bleeding should be less of a problem and way less hassle than the mechanical pump [which I will probably test and add back as a loss of electric power failsafe]
water in ANY fuel system should never be treated with methanol.... and in a diesel absolutely not....
just because some company markets a product that claims that its ok to do, doesnt make it so...
the water needs to be removed physically from the system.
water going thru a high compression diesel engine, no matter what it is mixed with, causes damage to the pistons.
all the methanol does for the water is allow it to pass thru the filters and injectors... and lets it into the cylinders to do its damage.
and if the stuff sets in the injector pump for a few days, the water and methanol will separate, and the water will start its corrosion/rusting process within the fuel pump immediately..
the only time its almost acceptable to use methanol to absorb water from a fuel system, is in a gas engine that you are going to empty the entire tank of water fuel from the tank, either by siphoning, or running it dry, and then filling with clean fuel...
by letting it sit for a few days, it can cause worse problems than what you had with just the water alone in it...
There are a couple of issues using existing tank trappings.
1- the main pick up tube is rarely low enough in the tank to really keep it free of crud and water. You want this tube within about 1/8" from the absolute lowest part of the tank.
2- the return line should ideally also use a dip tube to return the fuel "below water", so to say, as to avoid fuel foaming...
3- A polishing system won't do anything to get the tank clean, only filter what is in there. In order to keep the tank clean it would ideally need to be hand scrubbed and manually cleaned first. Once this is done a well designed high turnover polishing system will keep it crystal clear...
4- if removing the tank for cleaning have a welder throw in some tank bungs for a supply & return.. You can buy them at McMaster Carr and it will probably cot you about $50.00 with a reasonable welder.
5- Alternatively a Seabuilt tank clean out can be purchased with tank trappings already in it...
6- Can it work using existing tappings, sure.. Is it ideal, not really..
1- the main pick up tube is rarely low enough in the tank to really keep it free of crud and water. You want this tube within about 1/8" from the absolute lowest part of the tank.
2- the return line should ideally also use a dip tube to return the fuel "below water", so to say, as to avoid fuel foaming...
3- A polishing system won't do anything to get the tank clean, only filter what is in there. In order to keep the tank clean it would ideally need to be hand scrubbed and manually cleaned first. Once this is done a well designed high turnover polishing system will keep it crystal clear...
4- if removing the tank for cleaning have a welder throw in some tank bungs for a supply & return.. You can buy them at McMaster Carr and it will probably cot you about $50.00 with a reasonable welder.
5- Alternatively a Seabuilt tank clean out can be purchased with tank trappings already in it...
6- Can it work using existing tappings, sure.. Is it ideal, not really..
I think there's too much thinking in polishing fuel.
Yea, I know older fuel grows more bugs, sitting for long periods of time/changing temperatures can add bugs, water & sediment on tank bottom.
But, I feel the most important factor is first, the quality of the fuel.
I never fuel up at a fueling dock. These guys buy the cheapest fuel they can find. Not all fuels are filtered equally. I only have a 22 gallon tank so I jerry can my fuel to the boat. I use fuel from a specific gas station. It's highly filtered & looks like water it's soo clear.
Looks like aviation grade.
I also installed an access plate in my tank, so every 3 years or so, I check it out. Haven't had to clean it in over seven years now.
So ask yourself, does my tank have baffles? This could hinder polishing as the churning, or lack thereof can be affected.. Unless you can visually inspect the tank, how good was the polishing, how clean is my tank? If your tank has sludge, sure the fuel is better however, slosh up a dirty tank, and you still end up with clogging filters. So, what did you really gain?
I'll probably get a lot of flack for this.
CR
Yea, I know older fuel grows more bugs, sitting for long periods of time/changing temperatures can add bugs, water & sediment on tank bottom.
But, I feel the most important factor is first, the quality of the fuel.
I never fuel up at a fueling dock. These guys buy the cheapest fuel they can find. Not all fuels are filtered equally. I only have a 22 gallon tank so I jerry can my fuel to the boat. I use fuel from a specific gas station. It's highly filtered & looks like water it's soo clear.
Looks like aviation grade.
I also installed an access plate in my tank, so every 3 years or so, I check it out. Haven't had to clean it in over seven years now.
So ask yourself, does my tank have baffles? This could hinder polishing as the churning, or lack thereof can be affected.. Unless you can visually inspect the tank, how good was the polishing, how clean is my tank? If your tank has sludge, sure the fuel is better however, slosh up a dirty tank, and you still end up with clogging filters. So, what did you really gain?
I'll probably get a lot of flack for this.
CR
CR, the H31 holds 18 gallons so buying fuel ashore is possible, though getting a drop of diesel in the marina probably sounds a alarm immediately followed by strafing from North Island. How did you find the "perfect" diesel station? Could I find one if I needed fuel in small port in Mexico? Sure, the object is to start with a clean tank and keep it that way. Thought polishing was a means of transferring bad things from tank to a filter where it can be cleaned out more easily. Even with an access hole in the tank, unless you remove the tank, crouched in the cramped locker of the H31 to clean the tank is on my fun list just above a root canal.
Wuf,
I hear ya pal. Boats built in the '70's/80's did not allow for easy access in many cases.
I was lucky as I had ample room to my tank.
If you can clean your tank thru polishing, I would go that rout. At 18 gal., it's an open tank and a good polisher with the right equipment should do a good job.
Then, look at your name brand gas stations. Take your Gerry can & buy one gallon. You will know immediately if the fuel is well-filtered.
I've been using the same station for seven years. Independent stations, you never know what is mixed with what. This has been my experience. I worked petro/chemical for years. Independent fuel companies get what they can. Even with gas, you never know what mixes of fuel are in the tankers & not what the pump says it is.
CR
I hear ya pal. Boats built in the '70's/80's did not allow for easy access in many cases.
I was lucky as I had ample room to my tank.
If you can clean your tank thru polishing, I would go that rout. At 18 gal., it's an open tank and a good polisher with the right equipment should do a good job.
Then, look at your name brand gas stations. Take your Gerry can & buy one gallon. You will know immediately if the fuel is well-filtered.
I've been using the same station for seven years. Independent stations, you never know what is mixed with what. This has been my experience. I worked petro/chemical for years. Independent fuel companies get what they can. Even with gas, you never know what mixes of fuel are in the tankers & not what the pump says it is.
CR
Ruf,
here's some info on diesel fuel types for you pal:
1D Classification
High-speed diesel engines use 1D fuel, which improves cold weather starting and performance because of its lower pour point and lower viscosity. In cold weather, fuel must remain liquid at low temperatures, which gives it a lower pour point for optimum performance. The thickness or viscosity of fuel must also be lower during cold weather to maintain its ability to flow. 1D fuel has a lower BTU (British thermal units) rating, which results in lower miles per gallon (mpg). Starting and stopping a diesel engine frequently generally requires the use of 1D fuel, according to BanksPower.com.
2D Classification
According to Tomorrow'sTechnician.com, high-speed diesel engines use 2D fuel, which works best in warmer weather. It has a higher pour point and viscosity. Fuels with low viscosity do not lubricate as well, because they liquify too quickly at higher temperatures. With its higher viscosity, 2D fuel retains its lubricity and offers better protection for the moving parts of the fuel injection system. 2D also has a higher BTU rating, which means it provides better power and mileage.
4D Classification
Mobile engines cannot use 4D fuel. This classification of fuel works best when used in low-speed stationary units. It has higher viscosity and better lubricating qualities than other diesel fuels, but it generally requires warm ambient temperatures in order to flow properly in fuel systems.
Cetane Ratings:
The cetane rating is the measurement of diesel fuel's ignition quality. It signifies how easily it self-ignites in cold and warm temperatures. A common rating in the United States is 40, with the ultra low-sulfur diesel fuel rated at 55 to 60. Dodge, for example, recommends a cetane rating of 40 for temperatures above 32 degrees, and a rating of 45 for temperatures below 32 degrees.
Biodiesel Fuels:
Plant oils, such as soybean and palm, animal fat and recycled cooking oils are among the products used in the production of biodiesel fuels. Sometimes used as a separate mix, biodiesel is usually blended into conventional diesel fuel. The benefits of biodiesel fuels include reducing our need to depend upon foreign crude oil and lower greenhouse gas emissions. Changes in Diesel Fuel, a publication of the National Biodiesel Board, states, biodiesel fuels are nontoxic and biodegradable
Read more: http://www.ehow.com/list_7578063_diesel-fuel-differences.html#ixzz2sSvfvm5K
here's some info on diesel fuel types for you pal:
1D Classification
High-speed diesel engines use 1D fuel, which improves cold weather starting and performance because of its lower pour point and lower viscosity. In cold weather, fuel must remain liquid at low temperatures, which gives it a lower pour point for optimum performance. The thickness or viscosity of fuel must also be lower during cold weather to maintain its ability to flow. 1D fuel has a lower BTU (British thermal units) rating, which results in lower miles per gallon (mpg). Starting and stopping a diesel engine frequently generally requires the use of 1D fuel, according to BanksPower.com.
2D Classification
According to Tomorrow'sTechnician.com, high-speed diesel engines use 2D fuel, which works best in warmer weather. It has a higher pour point and viscosity. Fuels with low viscosity do not lubricate as well, because they liquify too quickly at higher temperatures. With its higher viscosity, 2D fuel retains its lubricity and offers better protection for the moving parts of the fuel injection system. 2D also has a higher BTU rating, which means it provides better power and mileage.
4D Classification
Mobile engines cannot use 4D fuel. This classification of fuel works best when used in low-speed stationary units. It has higher viscosity and better lubricating qualities than other diesel fuels, but it generally requires warm ambient temperatures in order to flow properly in fuel systems.
Cetane Ratings:
The cetane rating is the measurement of diesel fuel's ignition quality. It signifies how easily it self-ignites in cold and warm temperatures. A common rating in the United States is 40, with the ultra low-sulfur diesel fuel rated at 55 to 60. Dodge, for example, recommends a cetane rating of 40 for temperatures above 32 degrees, and a rating of 45 for temperatures below 32 degrees.
Biodiesel Fuels:
Plant oils, such as soybean and palm, animal fat and recycled cooking oils are among the products used in the production of biodiesel fuels. Sometimes used as a separate mix, biodiesel is usually blended into conventional diesel fuel. The benefits of biodiesel fuels include reducing our need to depend upon foreign crude oil and lower greenhouse gas emissions. Changes in Diesel Fuel, a publication of the National Biodiesel Board, states, biodiesel fuels are nontoxic and biodegradable
Read more: http://www.ehow.com/list_7578063_diesel-fuel-differences.html#ixzz2sSvfvm5K
The only major brand diesel station near me is Chevron. Only Ultra can be sold in CA and according to Chevron their CA product has a cetane rating of 52, considerably higher than in other states. Will try a gallon of their product to see how clear it comes out. Thanks, CR.
Centerline- Yes, I was approaching this from a petrol-centric perspective- I haven't spent much time on diesels and should have done a little research on it first, or at least quantified my response. That being said, the vast majority of information on issues with diesel fuel are geared towards cold weather and land applications. The biggest worry with water in diesel seems to be ice damage to injectors or clogging the fuel filter when an emulsifier is used to treat excess water in the tank. I'm guessing that yachting in a hard freeze is a fairly unusual event. As there are different amounts water in diesel, gasoline, and alcohol depending on its temperature, is your comment about water specific to salt/sea water? I'm not trying to be a troll- just want to understand.
Wufibugs- Now I get it! When we 'go over the border' up here, there's not much to think about with Canadian fuel, other than trying to figure out the best price with the double conversion. (CN$/US$ & L/gal.)
NO... my comment is specific to combustion engines. no matter the water source.
salt water is more damaging in every respect.
their are several problems with water in a fuel system... the freezing aspect is just one of them. it doesnt burn either...
a water molecule is big and has no compressive ability, as compared to a fuel molecule. when you add methanol, the methanol adheres to the water molecules and allows it to meld with the ethanol molecules (im not a scientist so I dont know the proper terminology) and it will pass thru a smaller orifice.. but still not burn quickly or properly.
(they actually make strainer funnels that work on the very principal of water molecules being substantially bigger than fuel molecules )
the water molecule, trying to squeeze thru an injector as fast as it needs to with 2500PSI behind it, can blow the fragile tip off of the injector... and in the time the water droplet is in the cylinder it acts on the top of the aluminum piston in the same way as the broken injector tip.... its like a BB in the cylinder....
This is what does happen whenever water is introduced into a running diesel engine.
although it wont cause instant failure, or catastrophic failure unless the injector tip breaks and hangs in a valve as it tries to escape the pounding its taking inside the cylinder.
usually the tip will pass thru and you can just install a new injector, but not always...
several or constant dosages of water in the pump and combustion chamber will take its toll well before the normal life of the engine would otherwise be considered "used up" ....
using an emulsifier to help get the water in the engine helps NO ONE except the people who formulated and sold the emulsifier, and the parts companies....
its always importent to have a good filter system and keep clean fuel... and a partially filled tank is bad, as it "sweats" the water out of the air from the vent tube, whereas a full tank has very little air in it to sweat the moisture out of.... in addition, a fuel tank that has more air exposed to it for a longer period,(such as a partially filled fuel tank) will degrade at a much much higher rate than a full tank that doesnt slosh around and has very little air being exposed to its surface.
its the oxygen in the air that degrades the fuel, as time alone wont do it in any measurable amount in our boating lifetime.
to explain, if you were to take a gallon of clean diesel and put it in a can, then seal it so air could not get to it, it will still be good to burn 10 years from now without any noticeable performance loss...
Thank you for the info, Centerline- I will add this to my library!
So has anyone installed a propane kit on your diesel? Yes, I'm kidding.
So has anyone installed a propane kit on your diesel? Yes, I'm kidding.