Fuel system plumbing question

[paulga]

The engine racor input is leaking at a joint, I'm going to disconnect the three hoses A B C, then remove in order the copper pieces DEFG (blue), clean and reapply thread dope then reassemble, then monitor if the leak would continue. The question is how to make a smaller mess in this process.

First, the thicker hose A is traced back to the valve on the portside fuel tank.

Because the same valve on the starboard side tank has always been off.

With the port side valve shut off, there are still lot of fuel in the hose.

Second, hose B and C are in and out of the priming pump. There is also fuel in these hoses

Do you use some tool to plug the hole immediately when taking the hose off the barb?

 

[O C Diver]

That setup is an accident waiting to happen. The first pipe nipple after the filter looks to be thin wall brass. Brass fatigues from vibration and is easy to shear off. Normally a manifold is mounted to a wall with a hose between it and the filter to reduce the mechanical leverage on that first nipple.

To your question: if the valve is closed on the other end, a one pint container would easily catch all the fuel in hose. If you plan to replace the hose, a pair of Vise grips or clamp can be used to pinch the hose closed just past the fitting you are removing it from. Always good to have a roll of paper towels or several boat diapers handy when working with diesel, oil, or antifreeze.

Drain the filter bowl first!

Ted

 

[Fleming]

Those look like unlabeled, unrated fuel lines. They should be labeled as A-1 fuel hoses.

 

[Portage_Bay]

Good points in the posts above.

In response to your questions how to minimize the mess. Some of the things I've used are flexible funnels sold as form a funnel or fold a funnel etc. Aluminum foil. Light aluminum baking pans. Anything that can be formed to make a funnel to direct the mess into a basin. The basin can be anything that can be cut, trimmed, deformed to fit where it needs to be. If you know the ID of the hose and it's small enough cut the threaded part of a bolt off, smooth the cut edge and jam that quickly into the hose, tighten the hose clamps. If you can't turn off the flow with valves be prepared to work very quickly. A nut driver the correct size in a small cordless drill will make tightening the hose clamps go quickly.

 

[paulga]

Good points in the posts above.

In response to your questions how to minimize the mess. Some of the things I've used are flexible funnels sold as form a funnel or fold a funnel etc. Aluminum foil. Light aluminum baking pans. Anything that can be formed to make a funnel to direct the mess into a basin. The basin can be anything that can be cut, trimmed, deformed to fit where it needs to be. If you know the ID of the hose and it's small enough cut the threaded part of a bolt off, smooth the cut edge and jam that quickly into the hose, tighten the hose clamps. If you can't turn off the flow with valves be prepared to work very quickly. A nut driver the correct size in a small cordless drill will make tightening the hose clamps go quickly.

Thanks.
I'll check the ID print on the hoses and get some pvc hose plug or barb inserts.

 

[paulga]

Those look like unlabeled, unrated fuel lines. They should be labeled as A-1 fuel hoses.

I remember those hoses have A1 letters on the wall

 

[paulga]

That setup is an accident waiting to happen. The first pipe nipple after the filter looks to be thin wall brass. Brass fatigues from vibration and is easy to shear off. Normally a manifold is mounted to a wall with a hose between it and the filter to reduce the mechanical leverage on that first nipple.

To your question: if the valve is closed on the other end, a one pint container would easily catch all the fuel in hose. If you plan to replace the hose, a pair of Vise grips or clamp can be used to pinch the hose closed just past the fitting you are removing it from. Always good to have a roll of paper towels or several boat diapers handy when working with diesel, oil, or antifreeze.

Drain the filter bowl first!

Ted

"first pipe nipple after the filter" -- Do you mean these two nipples

They have not leaked yet. I prefer to have the racor dual filter system that has symplified the two 3 way bypass valves into one, also looks more sturdy. But the existing racors are still running. This time Im just going to take off D through G, not going to disconnect the racors. If I put the upper bypass valve to "off", this would cut off the supply flow to both racors, then the fuel will not feed back from the racors either when I take off the couplers D through G. So no need to drain the racors first. Is my understanding correct?

 

[SteveK]

Curious why you started a new thread (again). This is the 3rd racor related thread on July 12th
Jan 5th racor drain fitting leaking last post July 10
Jan 18 fuel manifold installation
Curious as I cannot see any changes except the Gauges facing differently.
1) Have you confirmed that 1&2 have correct inlet/outlet
2) Have you repaired the leak found in previous thread
Below picture is from Jan 18 thread

 

[paulga]

Curious why you started a new thread (again). This is the 3rd racor related thread on July 12th
Jan 5th racor drain fitting leaking last post July 10
Jan 18 fuel manifold installation
Curious as I cannot see any changes except the Gauges facing differently.
1) Have you confirmed that 1&2 have correct inlet/outlet
2) Have you repaired the leak found in previous thread
Below picture is from Jan 18 thread
View attachment 156416

these threads are for different technical questions.
the original leak at racor #1 is already fixed by replacing the cracked bowl, see the new photo in this post

this thread is to tackle a new leak that is in fuel plumbing system. I got the idea of how to control the mess, but still need to clarify on some details with @O C Diver
so the thread could go long as needed

the manifold is still on my to do list, when I get time

 

[SteveK]

Is there a reason you do not post a success and leave me to wonder if you ever fix anything. The thread from Wednesday with the leak, did you resolve that. Right after your post that is dire, you post about heat shields. Did you fix that leak and drop that thread to start another?

 

[paulga]

Is there a reason you do not post a success and leave me to wonder if you ever fix anything. The thread from Wednesday with the leak, did you resolve that. Right after your post that is dire, you post about heat shields. Did you fix that leak and drop that thread to start another?

this post is a 80% success, considering the bowl fasteners are not yet sound

To resolve the new leak is the next objective, also purpose of this thread

that thread was named "racor drain fitting leaking". now that the drain fitting no longer leaks, i don't want to carry the story flow further away, so I started a new thread as it is more fuel plumbing related, even though unavoidably it will also relate to racor filters. I think this way will be more clear than extending the old thread

how do you think it could be organized more clearly?

 

[SteveK]

this post is a 80% success, considering the bowl fasteners are not yet sound

To resolve the new leak is the next objective, also purpose of this thread

that thread was named "racor drain fitting leaking". now that the drain fitting no longer leaks, i don't want to carry the story flow further away, so I started a new thread as it is more fuel plumbing related, even though unavoidably it will also relate to racor filters. I think this way will be more clear than extending the old thread

how do you think it could be organized more clearly?

Post 92 is an ongoing Racor thread that has 104 posts. Post 1 of this should have continued for continuation for those that started reading that thread. By starting this one there is no continuity. Why are we talking about pulling off hoses in this thread when you would need to do that the fix the dire leak. "racor drain fitting" readers will be left hanging after post 101 wondering if/how you fixed that leak.

 

[Comodave]

While I have not paid a lot of time reading this thread, I did look at the photos in the first post. It looks like a mess and leaks waiting to happen. IMO I would rip all of that mess out and start new. I clean all the fittings prior to starting, then put it all together and get the fittings tight and lined up correctly. Mark the fittings with a Sharpie so you will know that they are alll oriented correctly when assembling. Then I use Marine Tex for a sealant. I put quite a bit on so it will be sealed. Then assemble the whole thing and let the Marine Tex setup. After doing this I have never had a leak. I know the Marine Tex is permanent but if I ever have to change something I can get rid of the fittings and replace them with new ones. I think it is worth the possibility of having to buy new fittings at a later date and am willing to accept that for the very low possibility of leaks.

Design a new setup and start fresh and you will be better off in the long run. As said above mount all the fittings and shutoff valves on a bulkhead and have hose connecting to them so vibration will not be transmitted to the fittings. And label everything clearly so in the future there isn’t any questions as to what valve does what.

 

[paulga]

While I have not paid a lot of time reading this thread, I did look at the photos in the first post. It looks like a mess and leaks waiting to happen. IMO I would rip all of that mess out and start new. I clean all the fittings prior to starting, then put it all together and get the fittings tight and lined up correctly. Mark the fittings with a Sharpie so you will know that they are alll oriented correctly when assembling. Then I use Marine Tex for a sealant. I put quite a bit on so it will be sealed. Then assemble the whole thing and let the Marine Tex setup. After doing this I have never had a leak. I know the Marine Tex is permanent but if I ever have to change something I can get rid of the fittings and replace them with new ones. I think it is worth the possibility of having to buy new fittings at a later date and am willing to accept that for the very low possibility of leaks.

Design a new setup and start fresh and you will be better off in the long run. As said above mount all the fittings and shutoff valves on a bulkhead and have hose connecting to them so vibration will not be transmitted to the fittings. And label everything clearly so in the future there isn’t any questions as to what valve does what.

"mount all the fittings and shutoff valves on a bulkhead and have hose connecting to them"

Could you post an example pic?

 

[O C Diver]

"first pipe nipple after the filter" -- Do you mean these two nipples
View attachment 156415
They have not leaked yet. I prefer to have the racor dual filter system that has symplified the two 3 way bypass valves into one, also looks more sturdy. But the existing racors are still running. This time Im just going to take off D through G, not going to disconnect the racors. If I put the upper bypass valve to "off", this would cut off the supply flow to both racors, then the fuel will not feed back from the racors either when I take off the couplers D through G. So no need to drain the racors first. Is my understanding correct?

I wasn't aware of the second filter and would amend my original statement to say that hose should be plumbed from the filter selector valve to the fuel manifold. I'll post a picture of what fuel manifold looks like.

Ted

 

[dhays]

That is very nicely laid out Ted.

 

[Comodave]

That is very nicely laid out Ted.

That is indeed very nicely done. Well laid out and well labeled.

 

[paulga]

I wasn't aware of the second filter and would amend my original statement to say that hose should be plumbed from the filter selector valve to the fuel manifold. I'll post a picture of what fuel manifold looks like.View attachment 156434

Ted

Thanks for the picture.

I got the point of using manifold to make the plumbing immune to vibration. The design in your picture is designed well. on my boat, the space is just too limited in the same area to adding two manifolds. I plan to keep the current setup until the racors run out, then I can upgrade to 75500MAX2



In your photo, what is the plumbing piece in blue circle called?

 

[paulga]

While I have not paid a lot of time reading this thread, I did look at the photos in the first post. It looks like a mess and leaks waiting to happen. IMO I would rip all of that mess out and start new. I clean all the fittings prior to starting, then put it all together and get the fittings tight and lined up correctly. Mark the fittings with a Sharpie so you will know that they are alll oriented correctly when assembling. Then I use Marine Tex for a sealant. I put quite a bit on so it will be sealed. Then assemble the whole thing and let the Marine Tex setup. After doing this I have never had a leak. I know the Marine Tex is permanent but if I ever have to change something I can get rid of the fittings and replace them with new ones. I think it is worth the possibility of having to buy new fittings at a later date and am willing to accept that for the very low possibility of leaks.

Design a new setup and start fresh and you will be better off in the long run. As said above mount all the fittings and shutoff valves on a bulkhead and have hose connecting to them so vibration will not be transmitted to the fittings. And label everything clearly so in the future there isn’t any questions as to what valve does what.

I was thinking if there is a way to redesign just the top portion. please see below for my draft. This will get rid of those coupling pieces and also mount the valve to a manifold. it still has to use one 3 way T which I don't know how to further optimize. Comparing this with the plumbing in post #7, could you tell if this new design would work?

 

[dhays]

Thanks for the picture.

I got the point of using manifold to make the plumbing immune to vibration. The design in your picture is designed well. on my boat, the space is just too limited in the same area to adding two manifolds. I plan to keep the current setup until the racors run out, then I can upgrade to 75500MAX2

View attachment 156512

In your photo, what is the plumbing piece in blue circle called?

View attachment 156513

It looks like a pressure regulated bypass valve. I am not sure what it is regulating though. It would either send fuel from the return line back into the supply line if the pressure on one side is either too high or too low. I don't have anything like that in my boat (that I am aware of).

 

[O C Diver]

It looks like a pressure regulated bypass valve. I am not sure what it is regulating though. It would either send fuel from the return line back into the supply line if the pressure on one side is either too high or too low. I don't have anything like that in my boat (that I am aware of).

You are correct, it is a low pressure bypass valve. The picture is of my fuel polishing and transfer system. I can polish either tanks fuel and return it to either tank. The pump is capable of over one hundred PSI. So the bypass valve protects the fuel line from rupture if I forgot to open a return valve. This also explains why I adopted the routine of always leaving one set of tank valves open.

Ted

 

[TJM]

Fuel manifolds are the way to go as others have suggested. KTI systems (Keenan Filters) makes great diesel manifolds with ball valves attached.

 

[paulga]

I wasn't aware of the second filter and would amend my original statement to say that hose should be plumbed from the filter selector valve to the fuel manifold. I'll post a picture of what fuel manifold looks like.View attachment 156434

Ted

Could you add photos that show the tank fittings that the return hoses connect to?

 

[O C Diver]

Could you add photos that show the tank fittings that the return hoses connect to?

The return lines on the trawler had a 90 degree elbow that went into the top of the tank, without a valve.

I replaced all the fuel hose during the refit. All lines were 1/2" going to brass hose barbs, to brass 90s into the fuel tanks.

The fuel tanks are aluminum, so the area where the returns and draws are is probably 1" thick and threaded 1.5" female pipe thread. A stainless steel bushing with dielectric sealant reduces the pipe thread to 1/2".

Unfortunately I no longer own the boat and don't have pictures of the returns.

Ted

 

[paulga]

The return lines on the trawler had a 90 degree elbow that went into the top of the tank, without a valve.

I replaced all the fuel hose during the refit. All lines were 1/2" going to brass hose barbs, to brass 90s into the fuel tanks.

The fuel tanks are aluminum, so the area where the returns and draws are is probably 1" thick and threaded 1.5" female pipe thread. A stainless steel bushing with dielectric sealant reduces the pipe thread to 1/2".

Unfortunately I no longer own the boat and don't have pictures of the returns.

Ted

do you mean dielectric grease by saying dielectric sealant?
is this what you used on the threads of the manifold and elbows?

 

[O C Diver]

Paulga,
Going back to your original post, I'm not sure hose (A) is going to the tanks. Basically you have one fuel line coming to a "Y" valve that you can select one Racor to filter before going to the series of hoses.

From there it should go to the engine. Then a return line from the engine should go back to the two tanks. Hence, there may be more fuel in the hose than you think.

I would check the fuel pump for a maximum PSI. Most dedicated fuel pumps will have a maximum pressure below 25 PSI, negating the need for a bypass valve.

I would be curious to know if both supply fuel tank valves are open (the engine is simultaneously fed by both tanks). If so, I would probably open the return line valves for both tanks. If both supply valves aren't open, fuel needs to be returned from the take it was drawn from.

Ted

 

[O C Diver]

do you mean dielectric grease by saying dielectric sealant?
is this what you used on the threads of the manifold and elbows?

I suppose grease would work for a pipe thread sealant in this application as there is zero pressure.

The manifold and elbows aren't aluminum which negates the need for dielectric sealant. Just make sure whatever sealant you use is diesel rated.

Ted

 

[paulga]

Paulga,
Going back to your original post, I'm not sure hose (A) is going to the tanks. Basically you have one fuel line coming to a "Y" valve that you can select one Racor to filter before going to the series of hoses.

From there it should go to the engine. Then a return line from the engine should go back to the two tanks. Hence, there may be more fuel in the hose than you think.

I would check the fuel pump for a maximum PSI. Most dedicated fuel pumps will have a maximum pressure below 25 PSI, negating the need for a bypass valve.

I would be curious to know if both supply fuel tank valves are open (the engine is simultaneously fed by both tanks). If so, I would probably open the return line valves for both tanks. If both supply valves aren't open, fuel needs to be returned from the take it was drawn from.

Ted

yes, i traced the fuel hoses so I know hose A is fueled from the portside tank.

the genny takes fuel from the starboard side tank and return to the portside tank
the engine takes fuel from the portside and returns to the starboard side

these returns are thin cooper fuel lines that do not have a valve, they are as thick as the cooper line (purple D, to which hose A is tapped) shown in photo 2 and 3 in post #1.

the low pressure by pass valve as i understood, is a strain relief for the polishing pump that will create much higher psi that could render leaks if both return lines are turned off when this pump is turned on. the leak in this thread is likely due to the same reason.

 

[paulga]

The return lines on the trawler had a 90 degree elbow that went into the top of the tank, without a valve.

I replaced all the fuel hose during the refit. All lines were 1/2" going to brass hose barbs, to brass 90s into the fuel tanks.

The fuel tanks are aluminum, so the area where the returns and draws are is probably 1" thick and threaded 1.5" female pipe thread. A stainless steel bushing with dielectric sealant reduces the pipe thread to 1/2".

Unfortunately I no longer own the boat and don't have pictures of the returns.

Ted

is the female pipe thread welded to a hole on the top of the tank?
if the same hole is used as a source rather than a return, what tank fitting do you install there?

 

[SteveK]

the genny takes fuel from the starboard side tank and return to the portside tank the engine takes fuel from the portside and returns to the starboard side

Of course, ass backwards after being told return to the tank where the fuel came from. As long as both tanks are not filled to the brim, it may work that way.