Diesel fuel line fittings and selector valve questions

[ZZ13]

My boat has fuel tank selector valves for each engine. There is a compartment in the cockpit where those valves are mounted. 8 lines go through the deck hole into the valves. 1 supply line from each tank, 1 return line input from each fuel cooler, 1 return line output to each tank, and one output line to each engines RACOR filter system. That's a lot of fuel fittings to maintain. Well, one is leaking slightly - the port output that goes to the RACOR. I am trying to figure out how to twist and turn the mounting panel to get access to the fittings behind it, but there isn't much slack in the lines so I am going slow. First question, does anyone have trick to get access to the back of the valves and the fittings? The leak appears to be coming out of the threads. So I am hoping it just needs some tightening. Anyone have an experience as to what the odds of that are?

Now, I am considering ripping it all out and direct plumbing the port tank to the port Racor, the port return line to the port tank, and the same for the Starboard. That would eliminate all those fittings and the selector valves as well as a bunch of lines could be removed from the engine room. Has anyone done this and is there a reason this is a bad idea? I believe the next generation of my boat (the 420DB) did away with this selection, but maybe wrong there.

 

[my3sons]

Bill, I have not had to mess with those valves, so sorry no experience with that other than exercising them every now and again, but there must be a way to get at those?? If you plumb with out those valves in the line, you will not be able to shut off the fuel if you ever need to in an emergency (broken fittings etc). Or if you want to cross over because of ???? I don’t know, water in one tank because the cap was left loose on the deck fitting and every time it rains 100 gallons of water flows over the top of those deck fittings on its way overboard, sludge problem in one tank, level off the fuel load after running your gen at an anchorage for 4 days…I guess it’s your call, but I wouldn’t plumb right to the racor without a shutoff valve above tank height in the line. You know, like the shutoff valve for the genny fuel line that’s on top of the starboard tank. Maybe you can get that leak to stop.
Good luck

 

[ttmott]

Last year I completely went through the fuel system which included disassembling all of the hoses from the valves. Now my boat is a bit different but no less very hard to get to those fittings. I ended up for some of the inaccessible B-Nuts pulling the valve assembly with some of the hoses attached out of the compartment. I did a post a while back on all of that; you might do a search. The only things which would leak fuel would be on the return side of the system as all else operates at negative pressure.

 

[ZZ13]

Thanks Mark. Yup, that second paragraph I posted was more emotion than logic. You made some really good points.

 

[ZZ13]

Last year I completely went through the fuel system which included disassembling all of the hoses from the valves. Now my boat is a bit different but no less very hard to get to those fittings. I ended up for some of the inaccessible B-Nuts pulling the valve assembly with some of the hoses attached out of the compartment. I did a post a while back on all of that; you might do a search. The only things which would leak fuel would be on the return side of the system as all else operates at negative pressure.

Thanks. Sure looks like it's coming from the line at the bottom of the valve, which looks to be the one going to the Racor. I can see the two supply lines from the tanks and this line. But I can't see the return lines. I guess one of those fittings could be leaking and it's running down to what I can see. Time to break out the mirror on a stick and keep looking.

 

[ZZ13]

Ok. I just made some more room and I can see and feel everything. Looks like you me be right ttmott. All four fittings on the top of the valve are bone dry and dusty. At the bottom of the valve, the return line from the engine is in the rear of the valve and the fitting is all black. I couldn't see that fitting before. The hose fittings to the Racor is right next to it and is wet, but still brass in color. Incidently both the hose and the valve are female fittings. So there is an inline union adapter for each hose. Means the leak could be on either side or both sides of the inline adapter. And actually, I see the exact same thing on both valves now (black stuff all over the return fitting and wetness on it and the adjacent Racor line fitting). So both are doing the same thing, but the port seems worse. Can I just try tightening these? Why are they union fittings black?

Also, looks like I can rotate the panel 90 degress to get at everything if I remove the water tank fill hose, which runs through a cutout in the side of the panel.

 

[ttmott]

ZZ13 - those valves are Groco fuel selector valves http://www.groco.net/seacocks.htm
Note that the upper ports are larger and are the fuel supply and the lower are smaller and the return.
If you have a leak on the upper ports then you should see air bubbles in the racor filter which is not a good thing and will cause the engine to run badly. Again, the upper ports are in a negative pressure when the engine is running but the lower return ports are positive pressure.
You should be able to simply tighten up the fittings but note that all but the hose connections are pipe thread so don't over tighten as you may crack one of those expensive valves. Some thread sealant may also be necessary for the pipe threads. Use no sealant on the SAE / JIC hose fittings.
And, as an edit, I found several hoses with cracks in the outer covering; they were old and some had sharp bends in them so look for leaks in cracked hoses.

 

[ZZ13]

This is so helpful ttmott. Only one difference I noticed is my valves have "Anderson Brass" stamped on them. Also the top four hoses are not leaking at all. It's the bottom two fittings. One is the return line coming from the engine. And the other is the supply line going to the Racor. Once I verify that the leak isn't from the hose itself or from the valve stem, then I plan to remove those two fittings and reconnect them with Rector #5 sealant.

 

[ttmott]

Looks to be identical.... http://www.andersonbrass.com/SELECTOR_VALVES.PHP

 

[ZZ13]

I don't know what an SAE/JIC hose fitting is or how to recognize one. Is that what is crimped onto the end of the actual fuel hose?

 

[ttmott]

I don't know what an SAE/JIC hose fitting is or how to recognize one. Is that what is crimped onto the end of the actual fuel hose?

The hose end has what is called a B-Nut and seals to the conical end of the fitting it screws onto. There are two angles for the fitting ends SAE is 45 degrees and JIC is 37 degrees. My boat has a mixed bag so don't get them mixed up.....

 

[ZZ13]

The hose end has what is called a B-Nut and seals to the conical end of the fitting it screws onto. There are two angles for the fitting ends SAE is 45 degrees and JIC is 37 degrees. My boat has a mixed bag so don't get them mixed up.....

Got it. I'll be able to tell when I remove them.

 

[ZZ13]

I am finally getting around to this I managed to pivot the panel about 45 degrees to get access. The leaking fitting is wrapped with a blue paper towel in the picture. The hoses between it and me are the supply lines. One from each tank goes to a T fitting on they top valve. Then a hose each comes out of it and loops down to be the supply for the bottom valve. Looks like if I disconnect all of this supply lines I will get clear access to the leaking fittings at the bottom middle of each valve. I may turn this over to a mechanic. Not sure yet.

 

[ZZ13]

I am seriously thinking of getting rid of these tank selection valves. The replacement to my model, the 420DB, does not have them and direct connects the port tank to the port Racors and the starboard tank to the starboard Racors. Does anyone know why these valves were eliminated in the next generation model?

 

[Alex F]

Bill,

If my memory serves me right, 400DB was configured like 480DB and possibly the same applies to some DAs of the same production timeframe. In your case, the selector valves allows you to choose supply/return to the mains. The difference in 420DB and number of other models (500/520DB, possibly DAs as well, etc.) during the model change starting from 2004/2005, the selector valves are at the generator side, not the mains. So, I can choose feed/return from either port or STBD tank for the genny, but not the mains.

The bottom line is that we still have the selector valves, just for slightly different application.

 

[ZZ13]

I guess I don't understand your response relative to why? It appears the designers were not concerned about protecting a main engine from a bad tank, since they removed that capability from the 420. So relative to just the main engines I am trying to understand why it went from pulling fuel from either tank to only pulling fuel from one tank.

I guess a theory is the designers wanted a way for the owner to balance fuel levels and doing it through the generator was easier and less cost and less prone to leaks than the spaghetti hose method they used on the main engine approach.

 

[ttmott]

I guess I don't understand your response relative to why? It appears the designers were not concerned about protecting a main engine from a bad tank, since they removed that capability from the 420. So relative to just the main engines I am trying to understand why it went from pulling fuel from either tank to only pulling fuel from one tank.

I guess a theory is the designers wanted a way for the owner to balance fuel levels and doing it through the generator was easier and less cost and less prone to leaks than the spaghetti hose method they used on the main engine approach.

Well, I have a bit of a different take. I had a pickup tube in one of the tanks plug up and the consequential engine shut down. The valving allowed me to switch both engines to one "good" tank and get to port. In my case it was rather rough seas and having both engines was important and a much safer situation. My advice is to keep the switching feature.

 

[ZZ13]

Well, I have a bit of a different take. I had a pickup tube in one of the tanks plug up and the consequential engine shut down. The valving allowed me to switch both engines to one "good" tank and get to port. In my case it was rather rough seas and having both engines was important and a much safer situation. My advice is to keep the switching feature.

Ok. It does make most sense to keep it. I do plan to move the valves from the tight cockpit compartment, to the engine room, to have better access to the connections and to eliminate squeezing eight lines through a small hole in the cockpit floor.

I would still love to know why the designers did away with this "feature", but I guess I will never know. Although my hunch is it was simply a manufacturing cost reduction thing. Less material and less installation labor.

Thanks Alex and ttmott for your responses.

 

[Alex F]

Bill,

I would love to have both features and also asked myself the same question. If selector valve for the mains was used in earlier models, why get away from this and do genny selector instead, but not as an additional feature.

I'm not sure if you aware, but the fact that genny has feed and return selector valves, it can b e used as a "transfer pump". So, I can transfer fuel from one tank to another with genny running. However, this doesn't address an issue ttmott described.

Maybe Frank or Rusty know the reason SR shifted the approach.

 

[HUMPH]

I also use my fuel tank selector switches to balance the boat. The starboard tank has about 18 gallons more than the port since that is the only tank the generator runs on. When I am not going to be using the generator, I might run both engines from the starboard tank for a while to keep the boat level. During the summer when I run the generator more I do the opposite when needed to keep from listing.