custom diesel manifold

I came across this stainless gas flex manifold with pipe thread fittings. I have a persistent air leak or other gravity siphon issue and was thinking of using this for new supply and return manifolds. They are ul listed but I'm sure it is for gas use. My plumber says if it is good for gaseous fuel then it is also ok for liquid fuel. This is ahead of the lift pump so it is not pressurized. I want to eliminate a bunch of brass fittings and use this for selector valves. Any thoughts?

Excellent. Where'd you get it? Does it have tapered threads for standard ball valves? I want one or more for my hurricane heater.

These were at Home Depot for $15. Made in Korea. The threads are 1/2 and 3/4 pipe thread so the valves should go right in.

Gas as used in most homes,, Natural gas or propane is at about 1psi when delivered to appliances.

You might pressure test it in a pail of water with an air compressor , at $15 it would be cheap to know the PSI it is useful for if it blows..

Most fuel returns , and hydronic heat pressures are low , but A bilge full of fuel could be a bummer.

I'm not sure a typical plumber would be qualified to give this advice. Diesel fuel is quite different than natural gas. I would look at the specifications or contact the manufacturer.

Also it's not under pressure it's under vacuum in use. It won't leak fuel out but it might leak air into your fuel supply.

BTW: Don't use Teflon tape to seal fuel system connections, use pipe dope that's rated for diesel fuel.

Many products used for one application are more than suitable for another....a little thought and checking will help cement your decision.

A quick check of the specifications on the Home Depot site...rather than pondering who is qualified to give advice or not since we are all giving some sort of advice and few of us are diesel engineers...shows it is rated to 20psi.

I would have no problem using it as a fuel manifold or other liquid applications under 20psi.

We use those in our propane systems I do in the custom homes I build. We pressure test them to 100psi and let them sit that way through the entire built. If a sub breaches the system they know it ..as it makes quite a sound. I would have no problem using this for a fuel manifold.look on ebay for ss ball valves..you can get them for under $20.00 to go along with the manifold.
Hollywood

Polyconn makes a wide variety of anodized aluminum manifolds with a choice of the number of ports, sizes and spacing. They are reasonably priced too.

Pneumatic Manifolds – In-Line Manifolds | Polyconn

Most are rated 1,000PSI for air and 3,000PSI for liquid so you should never have to worry about leaks.

Larry
M/V Boomarang

Good morning Brett

I have to say your boat, with its new paint job, sure looked good last week.

BTW, if you need water I have 300' of hose on my foredeck you can use to reach the running faucet at the end of our float.

Here's a thought...

Why not simplify things a bit.

I know there seems to be a preferance to supply and return fittings, along with a bank of valves but its not the only way.

You could run just one supply and return line from one (or a pair) of tanks to your engine(s).

Then to move fuel around you could have a permenantly installed diesel fuel transfer pump.

Thats the setup on my boat. Each engine draws from its own tank. There is a reversable fuel transfer pump between the two tanks with a rocker switch on the dash.

Something to think about. Simple works. Less stuff to go wrong.

I'm not sure why all the worry about leaks...it's on the suction side of the system and you have Racor fiters, it shouldn't exceed 10 in hg or you need a filter change anyway.

I think that's the equivalent to about 5psi differential.

Thanks, Ken. I'll be down tomorrow to water up and bunker fuel too. Looks like my first trip is mid month.

I appreciate the thoughts on this piece of hardware. Thanks for those. It is about what I expected too. I'm going to remove all of the threaded pieces, short nipples, and brass t connectors and insert these. I'm also waiting for pricing on the maretron fuel flow parts needed to get fuel usage to the n2k bus.

Ron says;
"BTW: Don't use Teflon tape to seal fuel system connections, use pipe dope that's rated for diesel fuel"

In this pic does this look like "pipe dope" sealed fittings? I've got a gremlin fuel delivery problem and think something is leaking air. This setup is what the yard did when I was in Alaska.

Yellow Teflon tape is rated for fuel. If you are using straight threads, surely there is no requirement for tape/dope? I thought you needed to tape for tapered threads?

Eric, try opening that square plug at the top of the upper manifold when you are under pressure and see if there is any air trapped in that high area. That might help you troubleshoot the plumbing? The lower manifold has a high spot too but it will be much harder to check. Presumably the lower one is the return and so it doesn't matter if there is air in there.

In fact, take that top fitting off and reconnect it with the square plug facing to the left and you will eliminate that air trap.

The reason not to use tape (any color) for fuel is that small pieces of the tape can break off and enter the fuel system. I didn't come up with this myself, it's a pretty common recommendation.

Air leaks on the vacuum side can drive you nuts because you don't see any drips.

True about the bits but that's why God invented filters!

Looks like a nice manifold. It is worth checking the threads though. There are many different thread types which almost fit together.

The most common tapered thread is the US is NPT (national pipe thread) which is cut at a 60 degree angle.

Most other countries use BSP (British Standard Pipe) which is cut at 55 degrees. Both have 14 threads per inch for 1/2" pipe, so will screw together but will usually leak.

Eric,

I just purchased a Groco FV-65038-A to replace a similar collection of fittings. It reduces the number of joints and controls both supply and return with a single handle. It has positions for Port - Both - Stbd - Off.


It is UL and USCG approved. The supply fittings are 1/2" NPT and the return are 3/8" NPT. You will probably need 1/2" to 3/8" reducer bushings on the supply side.

It looks like it might reduce the number of threaded connections in your installation by at least 8 if I am counting correctly.

Use of Parker street t's in the supply outlet and return inlet could save two more connections.



Or maybe a barbed "T" to combine the returns.



Just some ideas for you.

Larry
M/V Boomarang

Wonderful information and advice. Thanks all.

Interesting about the BSP cut at 55 degrees. Don't think I'd be likely to buy that in a store.

At least now I've got a place to start.

Just saw your post Larry and that is now a "must do". Most of the time I change the draw from one tank to another by reaching down and over the running engine on the fly finding all 4 ball valves. Identifying which are which and changing them to the new position. Only got it wrong once. Engine quit right out in the Prince Rupert harbour.

So imagine how pleased I am to find your post.
Thanks big time.

Interesting about the BSP cut at 55 degrees. Don't think I'd be likely to buy that in a store.

About the only spot you will come across BSP is in imported shower and sink hardware.

The Groco FV-65038-A is a great unit , but be sure to paint a drawing of valve position for tank selection , so a sea sick crew member does not have to WONDER!

Neither one of us ever gets seasick.

But good point Fred there must be 4 positions in 180 degrees. Probably w no de-tents so setting the handle in a half way point should be easy. Not good. Reaching blindly over a running engine could easily be folly.

Perhaps I should move the whole thing aft and assessable directly at the (smaller) aft hatch where I can see what I'm doing.

Xsbank said:

True about the bits but that's why God invented filters!

Click to expand...

You will have connections past the filters. But why not eliminate the risk in the first place?

manyboats said:

Neither one of us ever gets seasick.

But good point Fred there must be 4 positions in 180 degrees. Probably w no de-tents so setting the handle in a half way point should be easy. Not good. Reaching blindly over a running engine could easily be folly.

Perhaps I should move the whole thing aft and assessable directly at the (smaller) aft hatch where I can see what I'm doing.

Click to expand...

Eric,

The valve has 4 positions at 3, 6, 9 and 12 o'clock (full 360 degrees) and there are solid detents at each position. The valve also has a long stem and can be mounted so that the handle is actually in an adjacent space, stateroom, through the pilothouse floor etc. That way, the handle can be readily accessible to select tanks or shut off the fuel in an emergency without having to enter the engine room.

Larry

I love it Larry,
It's getting better all the time. Put it in the head so I can sit there and contemplate what tank to choose .. Or up chuck. Oh I forgot I don't get seasick.

And the detent is very important.

I'm thinking I should post more of my problems here.

LarryM said:

Eric,

I just purchased a Groco FV-65038-A to replace a similar collection of fittings. It reduces the number of joints and controls both supply and return with a single handle. It has positions for Port - Both - Stbd - Off.

It is UL and USCG approved. The supply fittings are 1/2" NPT and the return are 3/8" NPT. You will probably need 1/2" to 3/8" reducer bushings on the supply side.

It looks like it might reduce the number of threaded connections in your installation by at least 8 if I am counting correctly.

Use of Parker street t's in the supply outlet and return inlet could save two more connections.

Or maybe a barbed "T" to combine the returns.

Just some ideas for you.

Larry
M/V Boomarang

Click to expand...

Man Larry I like this valve . I have way to many valves on mine and they are scattered out everywhere and not labeled very well. I have a total of five tanks . When I get stumped I still have to call the PO . He is A nice guy and doesn't seem to mind . He has a Lord Nelson Tug now . Great valve and good info.

Just make sure those valves are labeled well... I have seen them on lot's of boats and people have hooked some up to where the pointer is and some to where the handle is...probably not an issue for anyone and their boat...just when someone else needs to make the tank/feed swap.

As far as fuel connections past the manifold...there are 2 on my boat...one leaving the secondary filter and one entering the injector pump...while not the best resource to use...if you have to make repairs and don't have anything but tape...harly the end of the world if you are careful using the tape and in reality...there should only be 2 connections past the secondary fuel filter and many engines use flair fitting that require neither tape or dope (just for the reason stated).

psneeld said:

Just make sure those valves are labeled well... I have seen them on lot's of boats and people have hooked some up to where the pointer is and some to where the handle is...probably not an issue for anyone and their boat...just when someone else needs to make the tank/feed swap.

Click to expand...

You are absolutely right about the confusion surrounding fuel selector handles. Some use the small cast pointer opposite the handle to indicate the selection while others use the handle itself to indicate the selection.

I will be using a handle and plate similar to this to eliminate any confusion regarding the selection.



Larry

The first job some cruisers will do is to remove the fuel selector and filter bank from the engine room to an accessible location.

What sense does it make to have dual filters to switch to a fresh filter if the crudded unit is in the engine room , and you need to change it underway?

Same with house and start batts , out of the ER may double their longevity.

Boat assemblers want to get the boat paid for with the least amount of cost and effort to themselves.

So changes are frequently required to actually cruise.

Picking up what looks to be a really old thread, but the only one I could find.
Fuel transfer manifolds. If I can find a hard way to do something, I will.
So really keen to hear if anyone is able to show their manifold design and the way it works. I’ve got 4 tanks, and would love to streamline the process of fuel transfer.
Tried looking up the Groco link, but no longer available.
Thx in advance. Alan

Alan
When replacing my tanks I used 1/3 of the side tanks to become day tanks, 385 litres each/ So I ended up with 6 tanks. The only way fuel can get into a day tank is via the polisher. The custom manifolds mean that I can run from any tank and return to any tank. Polisher likewise. The system has served me well.

That looks very nice. Could I trouble you for a rough schematic of the system?