Changing out the sight tubes on fuel tank for remote tank/senders

[Barking Sands]

Nice job! I am interested in your experience based comment on Tygon. When I purchased my current boat 4 years ago the sight gauges were nylon hose. These were picked out by my surveyor and after purchase I replaced with Tygon fuel rated hose. My sight gauges are nicely located and with a huge engine room am happy with this arrangement. However your comment re Tygon failing concerns me. Can you add context please? FYI I generally close the sight gauge valves but have certainly left them open from time to time and am wondering if this is safe.
~A

If you take a look at this old thread you can see the OP found and slightly cracked sight tube. I dont know if this was Tygon or not but this is generally how they crack.
https://www.trawlerforum.com/forums/s32/fuel-tank-sight-tube-valves-54397-2.html

Dont get me wrong. Tygon is excellent hose and can last years. But they will eventually crack and leak.

On certain models of aircraft the inspection interval for what is called an Engine Minor inspection is every 200 hours. Essentially every couple of months depending on schedule. At that time a mechanic will uncowl the entire engine and closely examine everything. Every separate item is written up as a "squawk". He may be allotted 10 hours per engine. When done the inspector comes behind him and looks again. So generally everything is found. Keep in mind we have hundreds of aircraft come and go every year that are at different stages of life. So some of the Tygon that is found cracked could be years old. But probably not more than 5 years. Also keep in mind the conditions are a bit harsher. Aslo keep in mind Tygon is ONLY Used for drains. One end is usually attached to gang drain manifold and drains overboard. But still we find them broken at the clamp routinely and change it "on condition".

The other more critical hoses are changed every 5 years regardless of condition. I have many old hoses in my garage to use for various things from these scheduled hose changes

If I had sight tubes and was using Tygon I would apply the following for safety:

1) Keep valves closed when not checking levels
2) Put the changing of the Tygon sight tube on a scheduled interval along with oil changes and other scheduled items. I would probably make it every 2 years or maybe even 3.
3) Dont over tighten the clamps. This surely causes premature failure
4) take a close look at them every now and then with a flashlight and look for cracking just like in the link. Usually at the barb end or right at the clamp.

I dont mean to poo poo sight tubes and Tygon at all. Just apply a bit of logic and a slight change of thinking to include those tubes in your routine Mx and inspection. For many it seems to be a set it and forget it type of thing or out of sight out of mind. That is until it leaks and you also leave the valves open 24/7/365

And of course the above is just an opinion from my own experiences.

 

[Barking Sands]

Anyone got a mfr of Rupse to ask if it can be tilted ?

Floats really should not be tilted. Im sure a minor tilt would still work. Someone mention they have essentially 90 degree mounted floats. Ones you can put in from the side. I did find some but they did not have the variety of lengths and they were MUCH pricier. I did not do an extensive search so there may be more out there.

 

[SIBERNUT]

Floats really should not be tilted. Im sure a minor tilt would still work. Someone mention they have essentially 90 degree mounted floats. Ones you can put in from the side. I did find some but they did not have the variety of lengths and they were MUCH pricier. I did not do an extensive search so there may be more out there.

Id be looking at less than 10 degrees

 

[jleonard]

I consider myself as fortunate because the old school float type fuel gages always worked flawlessly and we’re very accurate.

 

[Barking Sands]

I consider myself as fortunate because the old school float type fuel gages always worked flawlessly and we’re very accurate.

Thats good. Hopefully you dont ever have to touch them. It seems every time I take one of those out and then reinstall it they never work the same again...lol. Seems like they work forever as long as you dont disturb them.

 

[Nepidae]

Fuel gauges for Sight tubes

While there is some merit in a fuel gauge for sight tubes I can think of a reason not to change.

Daily, when the boat moves, before I start the engines, I go into the ER and do visual checks. One of the things I look at are the sight glasses for fuel level. I also check engine oil levels, sometimes the trans oil levels, then I look at the Racor gauges located over the Racors.

I also do a visual check of the areas below the engines to see if the diapers show any oil on them.

A general look around to see if I notice anything out of the ordinary.

Then, I think it is OK to start the engines.

With gauges, I might not check the ER as often before we start for the day.

Of course, during our run I do more visuals and check temps with an IR gun on a number of components on the engines and around the ER.

I'm looking to put gauges on the water and holding tanks, but I'll leave the sight glasses on the fuel tanks. Since they aren't a true rectangle, a gauge would just be a guess anyway.

 

[Nepidae]

Forgot to mention.

I added external tanks for coolant for each engine. Makes checking that level very easy and I can also read that for temp with my IR gun as we move for the day.

 

[KnotYet]

While there is some merit in a fuel gauge for sight tubes I can think of a reason not to change.

Daily, when the boat moves, before I start the engines, I go into the ER and do visual checks. One of the things I look at are the sight glasses for fuel level. I also check engine oil levels, sometimes the trans oil levels, then I look at the Racor gauges located over the Racors.

I also do a visual check of the areas below the engines to see if the diapers show any oil on them.

A general look around to see if I notice anything out of the ordinary.

Then, I think it is OK to start the engines.

With gauges, I might not check the ER as often before we start for the day.

Of course, during our run I do more visuals and check temps with an IR gun on a number of components on the engines and around the ER.

I'm looking to put gauges on the water and holding tanks, but I'll leave the sight glasses on the fuel tanks. Since they aren't a true rectangle, a gauge would just be a guess anyway.

On blue water boats I think it's common to have the gauges marked in gallons or liters.
At least that's how my last boat was set up.

 

[Barking Sands]

While there is some merit in a fuel gauge for sight tubes I can think of a reason not to change.

Daily, when the boat moves, before I start the engines, I go into the ER and do visual checks. One of the things I look at are the sight glasses for fuel level. I also check engine oil levels, sometimes the trans oil levels, then I look at the Racor gauges located over the Racors.

I also do a visual check of the areas below the engines to see if the diapers show any oil on them.

A general look around to see if I notice anything out of the ordinary.

Then, I think it is OK to start the engines.

With gauges, I might not check the ER as often before we start for the day.

Of course, during our run I do more visuals and check temps with an IR gun on a number of components on the engines and around the ER.

I'm looking to put gauges on the water and holding tanks, but I'll leave the sight glasses on the fuel tanks. Since they aren't a true rectangle, a gauge would just be a guess anyway.

The fuel valves for the old sight gauges were back by the generator and transmission. All my other checks are from the front hatch. I do engine checks either way. I am currently making some "work platforms" to make getting in these spaces easier. If those turn out ok it will make getting to this area much easier and less hard on the knees.

If I feel there is any deficiency going forward there are 2 or 3 ways to add sight tubes back in that are not too difficult. But so far I am enjoying normal gauges.

If anyone wants to actually see the process I did make a video covering the details.

https://youtu.be/hYszrWzHLMo