Fuel Tank Sight Glass Material

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Pgitug

Pgitug

Guru
Joined
Jan 4, 2015
Messages
1,231
Location
Usa
Vessel Name
Escapade
Vessel Make
Nordic Tug 37 2002
I have two fuel tanks with plastic 1/2" OD tubes. They are pretty stained making reading the fuel level hard to see. Does anyone have a recommendation for replacement plastic 1/2" OD tubing that will stand up to both the heat of the engine room and the staining of the diesel?
 
Fuel tank sight tube material

Our American Tug uses the same system. I bought some Tygon tubing online from US Plastics. us plastics.com It has a yellow tint but the red fuel shows up fine. It has been about 14 months since replacement and still looks good.
 
We recently replaced the sight tubes on two of our four saddle tank with the other two to be replaced when the tanks are empty. After doing considerable research and talking to companies in the area who supply sight tube material we took their advice for the easiest solution and used clear PVC tubing. It will eventually stain but not for quite awhile and it's inexpensive and easily obtained. There are other tubing materials that are more resistant to staining but it's more expensive and all the suppliers of this tubing we located in our area required one to buy a minimum of a 50 foot roll. We only needed about eight feet.
 
Pgitug said:
I have two fuel tanks with plastic 1/2" OD tubes. They are pretty stained making reading the fuel level hard to see. Does anyone have a recommendation for replacement plastic 1/2" OD tubing that will stand up to both the heat of the engine room and the staining of the diesel?
Click to expand...

Thick walled vinyl tubing.
 
The tubing that was recommended to me on the Grand Banks Owners Forum was Tygon. This is the tubing that is reputed to be pretty resistant to staining and was the tubing I could only find sold in this area in 50' rolls. The distributors said they would not cut any off a roll.

So we went with the recommendation of clear PVC tubing. But if one can find Tygon in the amount one actually needs it is supposedly a better solution.
 
We used clear PVC tubing and it is crystal clear 4 years later.
 
Wire reinforced clear tubing and still good after 11 years.
 
Pgitug said:
I have two fuel tanks with plastic 1/2" OD tubes. They are pretty stained making reading the fuel level hard to see. Does anyone have a recommendation for replacement plastic 1/2" OD tubing that will stand up to both the heat of the engine room and the staining of the diesel?
Click to expand...

Here is the answer I found and am very satisfied with the purchase of 20 feet:

GO TO THIS LINK and read about details: Superthane® Ester Base Tubing | U.S. Plastic Corp. and 3/8" ID x 5/8" OD x 1/8" Wall Superthane® Ester Based Tubing | U.S. Plastic Corp..

GO TO THIS LINK to place an order and read about more details:
The product you are looking for is 3/8" ID x 5/8" OD x 1/8" Wall Superthane® Ester Based Tubing, Item #56417

PRODUCT DESCRIPTION:
This 3/8" ID x 5/8" OD x 1/8" Wall Superthane® Ester Based Tubing has a working pressure of 100 PSI @ 70°F and a burst pressure of 300 PSI @ 70°F. Standard length is 100' and it weighs 10.22 lbs per 100'. It has a durometer of 85 A (±5), a tensile strength of 6000 PSI and the elongation at break is 550%. Values are typical and should only be used as a guide.

Superthane® Ester Base Tubing
Clear, flexible, resilient, tough; resistant to oils, greases, and fuels. Extremely resistant to weathering, tearing, impact, radiation, and abrasion. Wide range of temperature resistance: -95°F to 185°F. Contains no plasticizer that can cause flow contamination or tube hardening. Manufactured from FDA-sanctioned ingredients for use with wet and fatty food contact surfaces. Can be heat sealed, coiled, fabricated, or bonded. Hydrolytic Stability -- Ester polyurethane does not react well with water, prolonged humid conditions, or attack from fungus. Superthane® PU tubing is much more resistant to pressure and vacuum applications than corresponding sizes of PVC or rubber. Although polyurethane is commonly used in fuel applications, due to additives in today's gasoline and petroleum products, field testing should be performed. Superthane® is a registered trademark of NewAge® Industries. Phthalate free. Standard length of 100'. Priced per foot; sold in 10 ft. intervals only.
 
Wxx3 said:
:thumb:Yes.

Glass is too fragile. Don't trade a small risk or a much larger one.:facepalm:
Click to expand...

Wish more people lived by this concept, especially those at ABYC sometimes.
 
doninfresno said:
Here is the answer I found and am very satisfied with the purchase of 20 feet:



GO TO THIS LINK and read about details: Superthane® Ester Base Tubing | U.S. Plastic Corp. and 3/8" ID x 5/8" OD x 1/8" Wall Superthane® Ester Based Tubing | U.S. Plastic Corp..



GO TO THIS LINK to place an order and read about more details:

The product you are looking for is 3/8" ID x 5/8" OD x 1/8" Wall Superthane® Ester Based Tubing, Item #56417



PRODUCT DESCRIPTION:

This 3/8" ID x 5/8" OD x 1/8" Wall Superthane® Ester Based Tubing has a working pressure of 100 PSI @ 70°F and a burst pressure of 300 PSI @ 70°F. Standard length is 100' and it weighs 10.22 lbs per 100'. It has a durometer of 85 A (±5), a tensile strength of 6000 PSI and the elongation at break is 550%. Values are typical and should only be used as a guide.



Superthane® Ester Base Tubing

Clear, flexible, resilient, tough; resistant to oils, greases, and fuels. Extremely resistant to weathering, tearing, impact, radiation, and abrasion. Wide range of temperature resistance: -95°F to 185°F. Contains no plasticizer that can cause flow contamination or tube hardening. Manufactured from FDA-sanctioned ingredients for use with wet and fatty food contact surfaces. Can be heat sealed, coiled, fabricated, or bonded. Hydrolytic Stability -- Ester polyurethane does not react well with water, prolonged humid conditions, or attack from fungus. Superthane® PU tubing is much more resistant to pressure and vacuum applications than corresponding sizes of PVC or rubber. Although polyurethane is commonly used in fuel applications, due to additives in today's gasoline and petroleum products, field testing should be performed. Superthane® is a registered trademark of NewAge® Industries. Phthalate free. Standard length of 100'. Priced per foot; sold in 10 ft. intervals only.
Click to expand...


I like the specs on this tubing. I like that it is 1/8" thick as opposed to the other tygon that is only 1/16" thick.
 
A real glass sight tube is the very best way to go. And not just a glass tube hanging out in the open waiting to get broken. Look at Freund, they have a drum sight gauge that could be used for most diesel tanks less than 24 inches or so tall. Kenco makes a very good sight gauge, and would be my choice. These are all REAL sight gauges and not the pretend stuff we see on pleasure boats. Compared to $5 worth of plastic tubing they are expensive, but IMO, well worth the cost. As an aside, properly installed glass sight gauges are no more a risk than any other material (the valve you know !) and a purpose built unit is much safer than a piece of plastic hose. Personally, I like the sight glass built into the tank, flanged on the outside and ring bolted all around. 3/8ths tempered glass About 1 & 1/2 inches wide and extending from top to bottom. More of a "window" into the tank than an external tube. But, this is big boat and industrial stuff, seldom seen on toy boats. And, it's best if the tank is built with this in mind. Although it can be retrofitted to existing tanks.
 
I put a sight tube on my fuel oil tank for my furnace at home. I went to my favourite marine mechanic and asked him to get me some. What he sold me (inexpensive) was a soft plastic 1/4" tubing that was rated for diesel fuel. Lasted with no signs of aging for 14 yrs, till the furnace was replaced and the installer put a different kind of gauge on the tank.
 
The plastic tubing works, I'm not saying it doesnt. Tanks with no access for cleaning work also. There are countless places on our boats where "good enough" was the way to go for the builder or the next guy upgrading. What I am saying, is that with a little more time and sometimes more $$, you dont have to settle for "good enough".
 
Sure...you can go astronomically overboard for safety features that add...possibly (till proven differently)....0.000001 percent safety upgrade.


That's the whole point...while the "best" can possibly provide 99.9% safety... a way substandard alternative...based on how may sight gauge disasters I have heard of....may only provide 99.89% safety....


I might be more likely to be hit with lightning while being eaten by an alligator because I fell over the side peeing because a meteorite hit me in the back of the head and I didn't take all the precautions in the reboarding thread.
 
psneeld said:
Wish more people lived by this concept, especially those at ABYC sometimes.
Click to expand...

Your comment puzzles me. The quote you are referring to mentions glass as a sight gauge material. Are you under the impression that ABYC sanctions this ? They do not as far as I can see in H-33.
 
Last edited:
Is anyone interested in a milled aluminum channel with slots to see the fuel level in the sight tube? What I was thinking was something about like a shelf standard with elongated slots to see the tubing. Run it from the top L to the bottom L and clamp it to the band clamps perhaps, or devise a T shaped mounting system that would secure to the tank wall or backboard and physically bolt to the channel. If something fell on the channel, it would protect the tubing. In the event of fire, it would protect the tubing from radiated heat. None of the mentioned tubings are over the 185 degree melting point, and I think ABYC requires 300 degrees for 30 minutes? I'll have to check on that.

So, is anyone interested?
 
boatpoker said:
Your comment puzzles me. The quote you are referring to mentions glass as a sight gauge material. Are you under the impression that ABYC sanctions this ? They do not as far as I can see in H-33.
Click to expand...
Ahhhhh...don't take that comment to seriously as I can't point to any specifics right now....

Just typically in safety, especially in regulation....too many rules are written for the extreme possibility versus the average operation.

Look at it that way and apply accordingly. If I missed spoke and every ABYC rule is properly tempered, I appologize.

My quick stab would be our discussion about propane on a flybridge being vented below gunner level...way too complicated on my boat for what it's worth...and to what probability gained? Just food for thought

Even sight gauges have a wide variety of risks and solutions...wwhat solves what adequately for safety?
 
As Kulas suggested, Kenco make a variety of quality level gauges. We use this magnetic type at work for high risk areas. Magna-Site Magnetic Level Gauge | KENCO

On my boat, I use cheap vinyl plastic tube and a good quality isolation valve that stays shut except when checking level. The clear hose will require replacing every few years. Works for me.
 
I’m resurrecting this thread. I’ve just had the boat surveyed for insurance purposes. Most recommendations are trivial to contend with but the surveyor came down hard on my fuel sight tubes: the material is considered unsafe. I’m not sure what the material is.

Fuel Polishing System and Racor 900 Main Fuel Filters.jpg

And

Petcock port rear fuel tank.jpg

Anyone have recommendations that can be attached to existing fittings?

Thanks, Jim
 
Last edited:
Shouldn't matter if the valves are kept shut off except when viewing level. That's the same arrangement my AT34 had.
 
The surveyor works for you. Ask him for a detailed written report on why the material is unsafe given the valves are only turned on for viewing and for recommendations on acceptable material.

Some surveyors like to show off there new education by applying new boat standards to older boats.
 
boathealer said:
Shouldn't matter if the valves are kept shut off except when viewing level. That's the same arrangement my AT34 had.
Click to expand...



My surveyor called out my sight tubes as well. His issue wasn’t the material, but the lack of a top valve. One of the things that I mean to do is put a valve at the top of the sight tube. Not a real high priority, but it is on the ever expanding list.

Btw, my sight tube are a clear plastic hose. So in a fire they can melt. I keep the valve on the sight tube closed.
 
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tiltrider1 said:
The surveyor works for you. Ask him for a detailed written report on why the material is unsafe given the valves are only turned on for viewing and for recommendations on acceptable material.



Some surveyors like to show off there new education by applying new boat standards to older boats.
Click to expand...


This surveyor has been around since Pontius was a pilot. Does a lot of commercial marine surveying. I’ve found that the petcocks are not fail proof...some of mine “weep” if left open, so I have a regular routine where I check all of them to ensure they are closed. I’d prefer spring closures on them. This really isn’t an option for me. I need to ensure that I’ve taken proper steps to comply.

Jim
 
What does your surveyor recommend?
 
When you turn in your survey to insurance, wait to see if they require you to correct it.
 
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