Copper fuel line to rubber fuel line ?

[Trawler_traveler]

I'm about to install an electric fuel priming pump. Our fuel lines are copper but I'll use rubber fuel hose to splice in the pump.

What I'm wondering is if I need to put hose barbs on the copper line after cutting it or if I can simply slide the rubber hose onto the copper line and double-hose clamp it in place ?

Thanks.

 

[Comodave]

I would not trust just putting the hose on the copper without a fitting and a barb fitting. Not sure what ABYC says about it but I would not do it.

 

[tiltrider1]

If you actually cut the copper tubing you will need to flare the end of the tube. You can buy a tube flaring tool at any automotive store. I recommend using a bubble or double flare.

 

[Trawler_traveler]

I would not trust just putting the hose on the copper without a fitting and a barb fitting. Not sure what ABYC says about it but I would not do it.

Thanks, that was my thought too.

If you actually cut the copper tubing you will need to flare the end of the tube. You can buy a tube flaring tool at any automotive store. I recommend using a bubble or double flare.

I have the bending and flaring tools and will look up how to do a bubble or double flare. Thanks.



-Sven

 

[Seevee]

Trawler traveler,


Agree with the others in that you need a fitting there. reverse (double flare) and AN fittings would be my choice.



ABYC has a bunch of specs on this but doesn't say you can use a barb.


Now if you don't have the tools and skills to make up hoses with AN fittings, there's a lot of good hose people that you can use. That's one job I farm out because one little mistake and you can have rubber bits in your fuel.



I don't like clamps on fuel hoses but ABYC permits them, however, must be double and have the properties of ~300 SS, min 1/2 in.

 

[FF]

Just sliding the tubing into a rubber fuel hose , with 2 clamps works just fine.


A fuel transfer or priming is usually under 10PSI , do no big deal.

 

[kchace]

If the ID of the hose is a close fit with the copper it will hold very well. Slide the hose on at least 3x the diameter of the copper and clamp it.

Ken

 

[rslifkin]

If the line is very low pressure or a suction line, as long as it's slid far enough onto the copper and double clamped, I'd be ok with it. If it's under any meaningful pressure, I'd want something more to retain the hose.

 

[tiltrider1]

Put a flare in it. That way the clamp has something to seal the hose to. Double clamping is fine as a get home solution but shouldn’t be a permanent fix.

 

[syjos]

Putting a small flare in the pipe will keep the hose from sliding off.

However, too large a flare will cut into the hose. I put a really small flare on the end of the pipe and smooth the sharp edge with sandpaper. Double flare would be ideal but hard to do a small one.

I double clamp.

 

[HopCar]

I’m in the camp that would just clamp it on the copper. If you slide the hose on far enough to get two clamps on, it’s not going anywhere.

 

[Lou_tribal]

I’m in the camp that would just clamp it on the copper. If you slide the hose on far enough to get two clamps on, it’s not going anywhere.

This is what I have. The coper tubing is 2 to 3 inches in the hose and never moved

L

 

[OldDan1943]

Over time diesel will soften the rubber and it may expand. IF you use a rubber hose, make sure it is fuel proof and use 2 clamps. Make a point to inspect the hose and connection.

I agree with Chace, slide the hose down at least 3x the diameter.

 

[Lepke]

Just sliding the tubing into a rubber fuel hose , with 2 clamps works just fine.

Ditto

 

[TG]

I'd use brass compression fittings on the copper and convert to male JIC then use Female JIC push-lok swivels for all the soft fuel line connections.

 

[psneeld]

While I agree that clamping the hose on the copper works fine and has been done on a lot of boats.... I like compression swivel connectors ...makes repairs so much easier.

 

[FF]

."makes repairs so much easier."

Its true that the rubber over time will become one with the copper tubing.A PIA.

But when purchasing the rubber if 3ft instead of 1 ft is bought, a sharp knife slid on the copper will reduce any take apart tine to near Zero.

The fuel style hose clamps can be reused almost forever., and can be found at most NAPA or auto shops.

 

[Nopistn]

Just sliding the tubing into a rubber fuel hose , with 2 clamps works just fine.


A fuel transfer or priming is usually under 10PSI , do no big deal.

I've done this many times, no problem.
I just slide the rubber a foot or so over the copper and put 3 clamps of it makes you sleep better.
I've also done this with 60psi water piping with good results

 

[Steve DAntonio]

I would not trust just putting the hose on the copper without a fitting and a barb fitting. Not sure what ABYC says about it but I would not do it.

Agreed. ABYC is clear, you cannot place a fuel supply hose over a smooth pipe (there is an exception for fill hoses), it must include serrations, barbs or a bead. Only one clamp is required for fuel hoses other than fill lines.

The Standards say...

33.11 CONNECTIONS - FUEL HOSE
33.11.1 Flexible hose not equipped with permanently attached end fittings, such as swaged sleeve and threaded insert, shall be attached with corrosion resistant metallic clamps.

NOTE: Some USCG Type A hose is not designed to be clamped.

33.11.2 The ID of a hose and the OD of a connecting spud or fitting must meet the specification in H-33 Table II.

33.11.3 Hose shall not be installed on helical threading or knurling that provides a path for fuel leakage.

33.11.4 Clamps depending solely on the spring tension of the metal shall not be used.

33.11.5 Clamps shall be installed to impinge directly on the hose and shall not overlap each other.

33.11.6 Clamps shall be beyond the flare or bead, or fully on serrations where provided, and at least 1/4 inch (6mm) from the end of the hose.

33.11.7 Hose used in the fuel tank fill system shall be secured to pipes (smooth pipes acceptable), spuds or other fittings at each connection, by at least two corrosion resistant metallic clamps with nominal band widths of at least 1/2 inch (12mm).

33.11.8 Hose used in the fuel tank vent system, or the fuel distribution and return line system, shall be secured to a fitting that is formed or machined to provide serrations, barbs or a bead with a minimum height of at least 0.015 inches (0.038 mm)

33.11.9 Hose connections used in the fuel tank vent system or the fuel distribution and return line system shall have at least one corrosion resistant metallic clamp with a minimum nominal band width as indicated in H-33 Table III.

33.11.9.1 All components of hose clamps shall have a resistance to corrosion equal to or greater than 300 series stainless steel.

33.11.9.2 Hose clamps shall be reusable.

 

[Steve DAntonio]

I'd use brass compression fittings on the copper and convert to male JIC then use Female JIC push-lok swivels for all the soft fuel line connections.

Just an FYI, PushLoks are designed to NOT be used with clamps, using a clamp cuts into the inside membrane of the hose, as the barbs are very sharp, because they are designed to be used with...no clamps.

PushLok is a Parker product, it is only supposed to be used with PushLok hose, the hose is special designed, somewhat like a Chinese handcuff, to grip the barb.

There is no Type A1 PushLok hose, most installations I encounter use common A1 hose with PushLoks, which technically are incompatible, and most have clamps, which again violates Parker's installation guidelines.

From Parker, "Note: Push-Lok hose is recommended for vacuum applications but not for cooling lines in air conditioners and heat pumps, or for hydraulic applications where extreme pulsations are encountered. Push-Lok is not recommended for any fuel." https://www.parker.com/static_content/LiteratureX/4281 B1.pdf

Parker does make a PushLok fuel hose, but it's not labeled A1, and must be used with HY fittings, which must be crimped.

Having said all that, I'll admit that the PushLok fittings are very convenient and make disassembly a snap. If you can find a similar flare fitting with a conventional barb, that would be better. I've never been able to pull any hose off of a PushLok fititng.

 

[dweller]

rubber clamped on copper

If you have time for it to cure, some 3M 5200 on the rubber to hose joint will make sure the joint will never leak.

 

[syjos]

If you have time for it to cure, some 3M 5200 on the rubber to hose joint will make sure the joint will never leak.

Bad idea.

I would never apply sealant to a hose/pipe joint.

Especially not 5200.

 

[Comodave]

Will 5200 stand up to diesel? I have never tried it and don’t think I would.

 

[Lou_tribal]

Especially that if some find its way in the line big troubles ahead...

L

 

[OldDan1943]

5200 is not the cure all on a boat.
Someone take away his tube of 5200

 

[Steve DAntonio]

Will 5200 stand up to diesel? I have never tried it and don’t think I would.

I know if one motor yacht builder that used it to seal bottom compression fittings on their FRP tanks. I know because they contacted me after a failure, looking for me to affirm their decision to use it, and of course I was unable to do that. Polyurethane sealant is not fuel-proof. Interestingly, polysulfide, i.e. 3M 101, no longer available, and Boat Life, still available, is. Biodiesel would exacerbate the problem.

Never the less, I would not use any type of sealant on hose to metallic fittings connections.

 

[rslifkin]

Outside of the boat world, any time I've had a reason to use sealant on a hose end, it's been RTV of a variety that'll hold up to the temperature and fluids involved. Acts as a lube while putting the hose on, doesn't prevent removal later, but greatly aids sealing.

Last time I did it was rubber hose onto a metal barb in a cooling system. When the weather got cold, the double-clamped hose would always have to be re-tightened to not weep a little due to the clamps not clamping as well once everything contracted. The RTV was enough to reduce the amount of clamping force required, so once the clamps had been heat cycled once and re-tightened, it never leaked a drop after that.

 

[Nomad Willy]

I use hose to copper tube connections on my Wabasto fuel line.

I get away w it because I use hose clamps that don’t have a flattish spot where the screw is for clamping and the pressures are extremely low.

But I never use any sealant .. goo. The hose ID is smooth as is the OD of the copper tube. Just a little clamping is all that’s needed.

One must be extremely careful IMO w any goo in fuel lines. A shade tree mechanic put too much pipe thread sealant on my fuel lines for the engine and over time bits of solidified goo got into the fuel pump. Caused engine slow downs over time and eventually engine stoppage. Either sealant tape or goo can cause this problem.

 

[Comodave]

5200 is not the cure all on a boat.
Someone take away his tube of 5200

I very rarely use 5200. I did use a bit this summer to permanently glue a aluminum drip edge onto my sundeck hardtop. Other than a transducer I almost never use 5200.

 

[Comodave]

I know if one motor yacht builder that used it to seal bottom compression fittings on their FRP tanks. I know because they contacted me after a failure, looking for me to affirm their decision to use it, and of course I was unable to do that. Polyurethane sealant is not fuel-proof. Interestingly, polysulfide, i.e. 3M 101, no longer available, and Boat Life, still available, is. Biodiesel would exacerbate the problem.

Never the less, I would not use any type of sealant on hose to metallic fittings connections.

Steve,

I am going to be replacing my port fuel tank this winter if all goes well. I have a Racor 900MA to replace the FG unit. What sealant would you recommend for the metal fittings?