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Fueling at the dock - What's wrong with my system?


MadDogMike

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A while back there was a thread about fueling your 'bu. I rigged up what I think is a pretty good system, but I'm having one issue that I hope someone can help me with.

I have two of the 14-gallon Flo n' Go gas caddies, but I got tired of dragging them up & down the hill from my house to my dock. So, I just ran 200 feet of heavy duty garden hose down the side of my property (where there's a flower bed, so it's covered in mulch so you don't see it) from my driveway at the house down to the dock. Then I hook the two caddies to that hose via a Y connection, open the caps for ventilation and let 'er gravity feed down to the dock.

IMG_0898.jpg

It works great, except for one problem. I was using a nozzle like the one on the left in this pic:

IMG_0895.jpg

However, gas was not flowing from the nozzle. If I removed the nozzle from the line, gas flowed freely, but with the nozzle, nothing! I know lack of pressure wasn't an issue, because I used to use this nozzle directly from the caddy and it worked fine. Now, with 2 caddies and the drop of the hill, the fuel flow is much greater. So, I figured maybe the valve in the nozzle had gone bad, so I bought a new & better model, the one on the right. Guess what? Same thing!

Does anyone know something about these nozzles what would prevent fuel from flowing even when there's plenty of pressure? Any suggestions?

Thanks,

Mike

Edited by MadDogMike
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sorry can't help you on the nozzle thing, but do you cap your garden hose every time before and after use? I would just be worried about debris getting in my gas tank. maybe those handles have filters?

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can't help w the nozzle issue but have to question running gas through an un-shielded hose.

not an expert by any stretch but i suspect that you need a heavy copper conductor bundled w that hose to defeat static charge.

i also suspect that garden hose will not hold up to gasoline usage for very long producing the possibility of a fuel leak/ explosion hazard.

  • Like 3
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I like the way you think, but I see some potential issues

1) as noted, static electricity. This can build up as the fuel flows through the rubber hose. This is one reason why the fuel inlet is grounded via strap and its recommend to allow the metal nozzle to rest on the inlet.

2) Garden hose will not last with fuel. It will deteriorate.

3) Those nozzles pictured look like a standard nozzle from a regular pump. They require pressure to over come the back-pressure valve that automatically kicks them off when the tank nears full. Im betting your gravity-fed system is not enough.

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Your concept is great. You will need to put in some better materals for the run from the tanks to the Bu. You will also have to find a way to keeping the fuel line clean from the mobile tanks to the oppisite end, Capping each side is a good start but you may also want to add some physical propection on each end, I'm thinking maybe a well rock of something similar. Make sure you run some sort of grounding straps or system. I really dont want to hear a big boom in atlanta.

Fuel filter, on the lower end maybe? Just thinking, it wont hurt.

As for your nozzle, I have no clue. A simple brass on off valve would suffice.

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Is it just me or would it seem like throwing a brass ball valve a couple feet from the end of the hose would work just fine...and just pay attention so you don't over fill...just my .02, but im redneck so i do all kinds of stupid sh** like that...haha

  • Like 2
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Thanks for the replies. Some notes on issues raised:

1.) Debris - yes, I cap the hose when not in use. Also the nozzles do include filters.

2.) Static - not sure it's really needed for this quantity and flow rate, but I suppose I could certainly add grounding straps fairly easily. Any suggestions for specifically what product to buy and where to get it?

3.) Hose - I'm not using "garden variety" hoses, these are heavy-duty industrial / agricultural hoses. I have one hose that's specifically designed for gasoline (the black hose pictured connected to the galvanized nozzle.) However, I can only find that hose in 10 - 20' lengths, I can't find anywhere you could buy them by the foot. I'm thinking my heavy-duty hoses will be quite durable, but I'm open to suggestions on where to buy 200' of fuel transfer hose.

4.) Nozzles - The galvanized one is not auto-shutoff, so I don't think there's any specific pressure required to make it work. Besides, as I said, it worked fine last year directly from a single gas caddy on the dock, where there was significantly less pressure. The red one is auto-shutoff, but that works via a venturi tube, not a back-pressure valve. Regardless, it's possible that the old galvanized one is just shot and the new red one has some other spring-valve that I don't know about.

5.) Ball valve - I actually put a brass ball valve between the hose end and nozzle, just to have a backup shutoff method. When I took the nozzle off, it flowed well, but the valve is too large to insert into the boat filler. A friend just suggested I just add a 1' section of hose after the ball valve, and that might do the trick.

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A friend just suggested I just add a 1' section of hose after the ball valve, and that might do the trick.

Thats what I would do, and I would look to see if there is clear hose that would be compatible with fuel, just so you could monitor the flow on the outlet side of the valve..

Edit:

And as for grounding the hose, having it laying on the ground, or even slightly buried in flower beds, I'm not sure what else you need to do to avoid static build up along the hose. I might suggest grounding your trailer hitch carrier with a simple wire connected to it and temporarily shoved into the ground while fueling, just to eliminate potential difference between that metal carrier and the ground (your tires are insulating it from ground right now) ....and don't wear shoes, so you'll be grounded too.

Edited by RTS
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Just curious what the height difference is between your car and the boat? I'm assuming quite a few feet. The additional hydraulic head could be tripping the nozzles. Try opening the ball valve near your nozzle 1/2 way to allow less pressure to the nozzle.

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Just curious what the height difference is between your car and the boat? I'm assuming quite a few feet. The additional hydraulic head could be tripping the nozzles. Try opening the ball valve near your nozzle 1/2 way to allow less pressure to the nozzle.

Yeah, quite a big drop. Here's a pic from the house, where the car would be, down to the dock:

IMG_0390.jpg

I'll give that a shot.

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for each foot of vertical drop, you get/gain 0.62 psi, now you need to calculate the line loss (hydraulic head) that is lost as the gas runs thru the hose. 200 lf of small diameter hose will restrict the flow to a pee sized stream as it enters the gas tank. Not sure what joe's comment is about tripping the nozzle due to the hydreaulic head?? There is either a back flow preventer or anti siphon device in each handle/nozzle.

A simple ball valve would suffice just short of the boat's gas tank. And will increase flow...a tad.

The static elec is a differnent issue...gas and gas fumes are highly volatile. the vehicle and rubber hose will not ground as they are not metal.

I use 2 5 gal motorcycle types jugs...each jug takes about 30-45 seconds to empty into the boat.....simple and does not require all the risk of leaks, grounding, etc.

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I use 2 5 gal motorcycle types jugs...each jug takes about 30-45 seconds to empty into the boat.....simple and does not require all the risk of leaks, grounding, etc.

But you have to lug them up & down the hill, and it would take 3 trips to the gas station to approximate the quantity with my method. I'll just do some simple grounding, thank you.

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Buy more jugs.....have your kids lug em down the hill...let em earn their allowance.

How heavy is an empty jug to lug up the hill??

Not heavy, awkward. Especially while carrying any other gear I need to bring up and down the hill. And it wouldn't be "an" empty jug, especially with your suggestion to buy more! So either I have to carry more or make more trips up & down the hill. My 10-month old won't be much help. :biggrin: I'll add some grounds and stick with what I got.

Edited by MadDogMike
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Wish I had the answer for you. All I can add, is we used to have a hand pump, attached to industrial fuel hose from a tank, at my old ski site. The nozzle was similar to what you show on the left. The crank also showed the gallon amount, passed thru the pump.

A good 200 ft. level ground. Pumped nicely. I'll look for one of those pumps online. Of course would require two people at that point.

Steve B.

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for each foot of vertical drop, you get/gain 0.62 psi, now you need to calculate the line loss (hydraulic head) that is lost as the gas runs thru the hose. 200 lf of small diameter hose will restrict the flow to a pee sized stream as it enters the gas tank. Not sure what joe's comment is about tripping the nozzle due to the hydreaulic head?? There is either a back flow preventer or anti siphon device in each handle/nozzle.

A simple ball valve would suffice just short of the boat's gas tank. And will increase flow...a tad.

The static elec is a differnent issue...gas and gas fumes are highly volatile. the vehicle and rubber hose will not ground as they are not metal.

I use 2 5 gal motorcycle types jugs...each jug takes about 30-45 seconds to empty into the boat.....simple and does not require all the risk of leaks, grounding, etc.

'Hydraulic head' is the gain in pressure over a change in height. 'Head loss' is the loss pressure due to surface friction. As long as there are not any kinks in the hose I would think the hydraulic head gain would out weigh the head loss. Assuming the change in elevation was around 100 ft that would be 62 psi of head gained by that distance. Depending on the flowrate and ID of the hose the head loss might or might not be an issue. I found this chart http://www.tamparubber.com/product_pages/mainpres.htm (its on the web...it must be true, I'd guess there is a flow rate of around 10 GPM, not sure of the diameter of the hose).

Mike stated that he gained pressure when running the 200' of hose, but maybe he wasn't comparing apples to apples. If the nozzle was on during one test and off during another, the nozzle could have restricted the flow to make it seem like an increase in pressure.

Because both nozzles worked correctly when directly connected to the caddy's I would put my $$ towards the change in pressure causing the nozzle issue when 200' of line is used. I'm not sure how these shut off nozzles work, but I would try to limit or increase the pressure and see if you notice any change.

It might also be an issue with a lot of air in the line, as the pressure differential between your tank and air in the hose would be negligible causing your nozzles to not work. You might want to try bleeding the line, attach a nozzle, and then try to fill.

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Looking on-line, most of the nozzles listed have a min and max flow rate.

I doubt if you have enough flow or pressure to make the nozzle work.

I would be worried about the overall safety of this set up.

A leak through the garden hose and fittings, grounding concerns, etc.

If you are going to do this, I would invest in fuel hose and some safety equipment to protect you, your family, and the environment.

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Looking on-line, most of the nozzles listed have a min and max flow rate.

I doubt if you have enough flow or pressure to make the nozzle work.

If that were true, the nozzle wouldn't have worked when just siphoning from a single caddy at the dock. The flow rate is much higher with the two caddies at the top of the hill...maybe it's too high? Anyway, I think I'll just stick with the ball valve and dispense with the nozzle. (Pun intended.)

I would be worried about the overall safety of this set up.

A leak through the garden hose and fittings, grounding concerns, etc.

If you are going to do this, I would invest in fuel hose and some safety equipment to protect you, your family, and the environment.

I still haven't found anywhere online where I can buy fuel transfer hose by the foot, but I'm willing to buy them if found. In the mean time I'll use my industrial/commercial hoses and monitor for leaks. (None so far!) I will be buying grounding wires and stakes to take care of that concern.

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'Hydraulic head' is the gain in pressure over a change in height. 'Head loss' is the loss pressure due to surface friction. As long as there are not any kinks in the hose I would think the hydraulic head gain would out weigh the head loss. Assuming the change in elevation was around 100 ft that would be 62 psi of head gained by that distance. Depending on the flowrate and ID of the hose the head loss might or might not be an issue. I found this chart http://www.tamparubb...es/mainpres.htm (its on the web...it must be true, I'd guess there is a flow rate of around 10 GPM, not sure of the diameter of the hose).

Mike stated that he gained pressure when running the 200' of hose, but maybe he wasn't comparing apples to apples. If the nozzle was on during one test and off during another, the nozzle could have restricted the flow to make it seem like an increase in pressure.

Because both nozzles worked correctly when directly connected to the caddy's I would put my $$ towards the change in pressure causing the nozzle issue when 200' of line is used. I'm not sure how these shut off nozzles work, but I would try to limit or increase the pressure and see if you notice any change.

It might also be an issue with a lot of air in the line, as the pressure differential between your tank and air in the hose would be negligible causing your nozzles to not work. You might want to try bleeding the line, attach a nozzle, and then try to fill.

Unless I am mistaken, that IS what I said, you'll gain .62 psi, per vertical foot, calculating the actual head loss at the outlet is a tad more time consuming and tricky, and I would need more info to accurately calcualte...You can look at tables all day,,,they'll give you an approx amount of flow....and after 200 lf of 1/2" to 5/8" it wont' be any where close to 10 psi...

62 psi (if there is 100 feet difference from outlet to inlet) is what is gained not by distance, but by change (increase or decrease) in elevation. And there are numerous factors when calculating headloss such as, fluid viscosity, temp, something called "n" value, etc. Kinks as you pointed out will also increase your headloss, as will any change if direction, ie elbows.

Obtaining your static head would be a good place to start. That is relatively easy to measure. Dynamic head is more difficult.

You could hook up an infinite number of gas tanks Caddys) to the 200 ft of garden hose and it would not increase flow at the outlet....as long as they were at the same elevation (sitting on the back of the SUV).

Flow (Q) is dependent on what your headloss is, not the other way around. If it wasn't every one would use little itty bitty garden hoses to move fluids around.

ANd you lost me on the last 2 sentences, specially withe the pressure differential...not sure exactly where/which points you are referring to. at the caddy you have 0 guage psi as it is open to the atmosphere and down at the nozzle when static you would have approx 62 psi if in fact there is 100 feet difference in elevation.

AIr will escape from the caddy and the 200 ft of garden hose, cause air has a a lower specific gravity that the gasoline....air bubbles will rise to the open atmosphere (caddy). One reason why he has the caddys vented (like he does with the caps off) so that he doesn;t create a vacuum when trying to empty the caddy, which would decrease his flow, Q, at the outlet.

Edited by [email protected]
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[email protected], are you sure about that .62 psi "gain" per vertical foot? It would appear not accurate.

A cubic foot of water weighs 62 pounds but is exerted over 144 square inches. Your computations would be correct for WATER and if we were computing pound feet, which we are not. It's further incorrect because the liquid in question is gasoline, which is lighter than water and weighs 47 pounds per cubic foot and therefore exerts .32 psi.

It would appear that, for water at least, the multiplier to be used is .43 since one cubic foot of water exerts .433 pounds per square inch (.43 psi) (there are 144 sq inches in a cubic foot of water, not 100). Wrong? IF so, how?

image6AS.jpg

A 12" x 12" x 12" container, one cubic foot, of water weighs approximately 62.4 pounds. The total pressure exerted against the bottom of the container is 62.4 lbs. Thus each square inch of the bottom of the container has a pressure exerted against on it of 0.433 lbs. per sq. in. (62.4 lbs. divided by 144 sq. in.). Water pressure is usually stated in pounds per square inch (psi). So a column of water one foot high exerts a pressure of 0.433 psi, or 0.43 psi.

The most common U.S. unit of measure of water is the gallon. A gallon of water contains 231 cubic inches. The cubic foot container which we just used contains 1728 cubic inches (12" x 12" x 12"). By dividing the 1728 cubic inches by 231 cubic inches, we find there are 7.481 gallons of water in a cubic foot. It is necessary to deal with gallons per cubic foot frequently and the approximation of 7.5 gallons per cubic foot is normally used. One gallon of water weighs 8.34 lbs. (62.4 lbs. divided by 7.48 gal.).

Since water pressure is dependent on weight, it is also directly proportional to elevation. If the container were ten feet high instead of one foot, the pressure on the bottom would be ten times more than a one foot column or 4.3 psi. If the pressure in a water main resulted from water in a storage tank, with the top of the water 100 feet above the main, the pressure in the main would be 43 psi. (100 x 0.43 psi).

The difference in elevation which determines pressure is referred to as head. A 100 foot head has a pressure of 43 psi. Head is generally measured in feet and pressure in pounds per square inch. To convert from pressure in pounds per square inch to head in feet, multiply pressure by 2.31 (43 psi x 2.31 = 100 ft.)

Edited by 85 Barefoot
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Have you looked into using pipe rather then hose? The down hill run looks fairly consistent. Trench it shallow just under the ground/ground cover next to the steps. Might be cheaper then hose suitable for gasoline.

  • Like 1
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Yeah, quite a big drop. Here's a pic from the house, where the car would be, down to the dock:

IMG_0390.jpg

I'll give that a shot.

That's a beautiful setup, what lake are you on?

On topic, your nozzle may not be working because of air in the lines. I'm sure you are hooking up your nozzle to the hose end at the dock before hooking the hose up to the fuel jugs at your car, so the line hasn't been purged of air. You could be holding some pressurized air in the fuel nozzle (due to the head pressure from elevation) preventing it from opening as it should. I haven't used those before so I don't have any better ideas, but try putting a ball valve inline just before the filler nozzle. Use the ball valve to purge the air, close it, hook up your nozzle to the ball valve, and open the ball valve, to see if that makes a difference. That could be why they worked before when hooked up directly, as it's easy to purge air out of a short hose, and the head pressure would be lower.

I would recommend at least using hose rated for gasoline use. While the hose you are using now may be heavy duty, there is no guarantee that it won't deteriorate from fuel exposure, especially since most fuels have ethanol in them now. Any chemicals/byproducts that are dissolved out of the hose are now being fed into your engine and could lead to clogged injectors in the future if they turn to sludge sitting on the bottom of your tank.

Edited by Brett B
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