Copper TIH veggie fuel lines.

For discussing the modifications needed for diesel vehicles to run with 2 tank veggie oil conversions.

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Copper TIH veggie fuel lines.

Postby Welder » Sun Mar 30, 2008 4:16 am

Hi guys.

I have been weighing the options regarding heated veggie lines and I'm wondering who's got experience with copper tube-in-hose veggie fuel lines.

Usually people buy/build aluminum TIH systems, but I'm interested in copper because it has even better heat transfer ability than aluminum and also has a higher temperature rating.

One concern I have regarding copper lines is whether anyone has experienced vegpoly formation inside their copper lines?

How have your copper lines been performing?
"Is there anybody out there?"

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Postby SunWizard » Sun Mar 30, 2008 9:01 am

The heat transfer of aluminum is very high and close to copper, and alum. is far cheaper. Temp. rating is not concern either since both are above what temps. your VO will hit. And you can get alum. in the same temp ratings as copper. The higher temp ratings of both metals are harder to bend and more likely to stress crack over time.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
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Postby Unique » Sun Mar 30, 2008 3:33 pm

I made my heat exchanger out of copper. I have not tried it out yet, but I will in the next week.

<a><img src="http://img169.imageshack.us/img169/2719/new070ep7.th.jpg" border="0" alt=""><br><br>
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Postby Welder » Mon Mar 31, 2008 2:59 pm

SunWizard wrote:The heat transfer of aluminum is very high and close to copper, and alum. is far cheaper. Temp. rating is not concern either since both are above what temps. your VO will hit. And you can get alum. in the same temp ratings as copper. The higher temp ratings of both metals are harder to bend and more likely to stress crack over time.


McMaster-Carr lists the max temp of their soft bendable coiled aluminum to be 180 deg F. With a looped return, I think a well designed SVO set up could be feeding 200+ deg F veggie back into the aluminum loop. Sure, there's an extra margin of safety built into the max rating, but why push it? Aluminum is cheaper than copper, but WVO is waaaaaaay cheaper than ULSD or pump B100.

I understand peoples desire to skimp on their conversions to save $$$, but most the kit vendors remind us that SVO is expiremental in site disclaimers. A dollar saved is a dollar earned, unless I fry my IP with a coolant leak, then a dollar saved becomes several dollars wasted.

I know someone might say that there's no reported case of aluminum TIH failure related to over temp fuel, but REPORTED is the key word. How many wimpy rotary IP shafts snapped back in the early days of SVO and went unreported until others admitted their bad experiences?

McMaster lists a very heavy wall 1/2" soft aluminum tube in their selection. This extra meatty tubing costs more than the thinner walled stuff, but may offer a reasonable extram argin of insurance and still be cheaper than their equivelant sized copper line.
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Postby Welder » Mon Mar 31, 2008 3:03 pm

Unique wrote:I made my heat exchanger out of copper. I have not tried it out yet, but I will in the next week.

<a><img src="http://img169.imageshack.us/img169/2719/new070ep7.th.jpg" border="0" alt=""><br><br>


If the heat transfer is weak, try spacing the wraps of fuel line further apart than you did in the picture. I know that sounds counter intuitive, but a wide enough gap will allow you to melt some solder along the entire wrapped length. This will increase heat capacity by increasing direct metallic contact through the solder.
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Postby David » Mon Mar 31, 2008 6:03 pm

I made my HE out of copper 16 months ago and have had no problems with poly or any other type of reaction. I believe water is a required factor in reactions with copper ( or steel or anything else) and as I dry my oil carefully, I am not going to worry about it unless I physically see i have something to worry about.

With my HE I wrapped the coil and also soldered the entire length of it to the coolant pipe for the proper heat transfer. I think the contact area of the 2 pipes would be very patchy otherwise. I want to get some of that foam covering like they use in air conditioning to insulate the pipes but carefully fill the area between the pipe and the insulation with fine sand to further elp with the heat transfer. I think this may make the HE a little longer to warm up but once it does the heat transfer will be better and after stops, there will be better heat retention for startup.

There is also thick walled copper tube available for the new high pressure air conditioning systems that are now being used.
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Postby SkySkiJason » Tue Apr 08, 2008 10:26 am

Unique wrote:I made my heat exchanger out of copper. I have not tried it out yet, but I will in the next week.

<a><img src="http://img169.imageshack.us/img169/2719/new070ep7.th.jpg" border="0" alt=""><br><br>


That thing is a chicken skin factory! OK, it might be alright if it is just before it gets burned and a looped return. Before you install it, it would be fun to circulate VO thru it back into a bucket and see how long it takes to make poly...!

I saw a HE very similar to this in a steel fuel tank. In that application it took a couple months to plug all th VO lines w/poly. The whole system had to be removed. Obviously, this is a different application - but I still wouldn't use it based on my experience.

Why not make something similar w/aluminum? How about a peice of alum a couple inches ID, rectangle is fine - w/a alum coil running thru it. A tiny heated fuel tank. Built from scraps off the fab shop floor. 8)
2001 F-350, DRW, 4x4, XLT Crew Cab, flat bed, 7.3, 6 spd, Dipricol Optix gauges, DP tunes - Single-Shot injectors! Vegistroke-style WVO conversion, 55,000 VO miles so far - 190 deg VO before the heads
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Postby SunWizard » Tue Apr 08, 2008 10:33 am

Welder wrote:McMaster-Carr lists the max temp of their soft bendable coiled aluminum to be 180 deg F. With a looped return, I think a well designed SVO set up could be feeding 200+ deg F veggie back into the aluminum loop.

My TiH is from the tank up to the valve. There is never any looping back into the TiH, so it never gets that hot. If you don't like that tube, get the next higher temp rating, the soft copper is the same 180F temp rating.

Note that alum. is rated for 1008psi, which is no where near where we are running, and thats why the temp rating is low. The temp rating at 50psi is going to be very high, they just don't show a chart.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
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Postby David » Tue Apr 08, 2008 4:03 pm

SkySkiJason wrote: Before you install it, it would be fun to circulate VO thru it back into a bucket and see how long it takes to make poly...!

I saw a HE very similar to this in a steel fuel tank. In that application it took a couple months to plug all th VO lines w/poly.


Yeah, I agree!
It would be good to do that so you could see if it does cause Poly or the whole Copper / Steel thing is the complete load of crap I am completely sure it is.

Circulate some properly dried oil that passes a hot pan and then do the same with some oil that isn't dried. Heat them a bit if you like for good measure.

I'll put money on getting poly out of the wet stuff and bugger all out of the dry stuff.
As I said, I have a HE that is of highly similar construction and also made entirely of copper and have had no problems with it. That is using copper in everyday real world practical use over 16 months, not some theoretical hypothesis.

Copper and steel is not the cause of Poly, water is. Dry your oil and you have nothing to worry about.
_____________________

I don't give a damn about what might or could happen until a significant group of people can tell me it HAS happened to them.
Until then, it's just more endless gloom and doom Veg folk law.
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Postby SunWizard » Tue Apr 08, 2008 4:16 pm

David wrote:Copper and steel is not the cause of Poly, water is. Dry your oil and you have nothing to worry about.

I disagree, oxygen is the main cause of poly. And in real world use I have seen several tanks where they used copper heat exchangers in the tank (greasecar kits) where they had bad poly formation after about 1 year. Their VO was dewatered well, I tested it. I have found water does help accelerate poly but is not the main factor.

I have stored completely dewatered VO in half filled steel barrels and had nasty poly form in only 3 months.

There is a great deal of research already done on this that backs this up, some of it is linked in the poly thread.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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Postby David » Wed Apr 09, 2008 2:56 am

SunWizard wrote:I disagree, oxygen is the main cause of poly.


That Being your belief, what do you think the chances of a HE made from copper are for causing Poly? I would take it that there would be no air in a HE so do you think there is a risk of the copper causing poly in this configuration?
_____________________

I don't give a damn about what might or could happen until a significant group of people can tell me it HAS happened to them.
Until then, it's just more endless gloom and doom Veg folk law.
David
 
Posts: 333
Joined: Thu Mar 06, 2008 4:12 am
Location: Sydney Australia

Postby BMW Fan » Wed Apr 09, 2008 4:43 am

I support Davids view.
There is no polymerization INSIDE a closed system. Nobody ever reported a problem using my FPHE's ( copper brazed ) and the ones from the competition.
I have used copper lines and even after many years the inside is blank like being installed yesterday.
The problem occurs only if used in a tank and exposed to air.
It also depends which kind of oil is used.
Again, the OUTSIDE in connection with air creates the problem not the INSIDE.
Many test of the most popular report are done exposing copper , steel etc. to air and in some cases extra heat was added.
That kind of test is needed for the food industries. That’s why all restaurant equipment to clean oil MUST be made of stainless steel.

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Postby Welder » Wed Apr 09, 2008 5:06 am

Although I agree that exposure to oxygen and heat are the main accelerants in vegpoly formation, I can't help wondering if the water reported to cause vegpoly is/was somehow mildly contaminated with calcium, lime, iron or some naturally occurring water based acid, like tannic acid from decaying leaves etc?

Would Australian well water containing iron rust and tannic acid accelerate vegpoly?

Dana once mentioned that he figured vegpoly was accelerated by water exposure as he thought H2O would be a carrier of O2.

Could PH level or mineral colloids enhance this?
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Postby SunWizard » Wed Apr 09, 2008 8:40 am

I agree poly won't happen inside a closed system, there is no oxygen. I have said this repeatedly in many places here, see the poly thread. In tanks and in storage is where the problem occurs, due to oxygen. All I was referring to was David's point about water being the cause.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
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Postby SkySkiJason » Thu Apr 10, 2008 2:58 pm

oops!
Last edited by SkySkiJason on Thu Apr 10, 2008 5:52 pm, edited 1 time in total.
2001 F-350, DRW, 4x4, XLT Crew Cab, flat bed, 7.3, 6 spd, Dipricol Optix gauges, DP tunes - Single-Shot injectors! Vegistroke-style WVO conversion, 55,000 VO miles so far - 190 deg VO before the heads
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