Sight tube indicator

[AntarcticPilot]

My diesel tank has a sight tube so I can check the level of fuel remaining. No problem - except that the level is difficult to see in the gloom of the cockpit locker where it lives. We usually end up leaning into the locker and back-lighting the tube with a torch, and even then it can be tricky spotting the fuel level. So, I have been thinking of putting some sort of brightly coloured float in the tube, so the level is clearer. The question is, what do I use? The tube itself is some sort of armoured flexible clear plastic, OD about 15mm; inside diameter at a guess around 10mm - it's quite thick walled. Some sort of bead would do, but I need to be sure that the bead won't interact with diesel in any way.

 

[sailorman]

I changed my sight tube a while ago as the red had stained it & when filled with white it was difficult the see, i have a valve at the bottom to isolate the tube. if you utilise a ball i have always wondered if it would stick at the top

 

[thalassa]

My diesel tank has a sight tube so I can check the level of fuel remaining. No problem - except that the level is difficult to see in the gloom of the cockpit locker where it lives. We usually end up leaning into the locker and back-lighting the tube with a torch, and even then it can be tricky spotting the fuel level. So, I have been thinking of putting some sort of brightly coloured float in the tube, so the level is clearer. The question is, what do I use? The tube itself is some sort of armoured flexible clear plastic, OD about 15mm; inside diameter at a guess around 10mm - it's quite thick walled. Some sort of bead would do, but I need to be sure that the bead won't interact with diesel in any way.

I've stuck a strip of cheap LED lights behind the tube, powered by a 9 volts battery via a momentary switch. Couldn't be clearer, even with white diesel.

 

[vyv_cox]

The ones used for central heating oil include a green plastic ball that floats on the oil. Like this http://www.ebay.co.uk/itm/Replacement-Oil-Tank-Sight-Gauge-Tube-Kit-/271931509559

 

[AntarcticPilot]

The ones used for central heating oil include a green plastic ball that floats on the oil. Like this http://www.ebay.co.uk/itm/Replacement-Oil-Tank-Sight-Gauge-Tube-Kit-/271931509559

The green ball looks like just what I need. Now to find a source of green balls!

 

[AntarcticPilot]

I've stuck a strip of cheap LED lights behind the tube, powered by a 9 volts battery via a momentary switch. Couldn't be clearer, even with white diesel.

The locker is a cockpit locker, which is the home to wet ropes and fenders and so on. I don't think an electrical system would last very long in it, but the concept is a good one.

 

[sailorman]

The green ball looks like just what I need. Now to find a source of green balls!

Ive got a few black ones i have collected

 

[thalassa]

The locker is a cockpit locker, which is the home to wet ropes and fenders and so on. I don't think an electrical system would last very long in it, but the concept is a good one.

Mine is also in a locker with wet ropes and fenders. No problem so far after 3 years with the same battery...

 

[Minchsailor]

I put a bit of white painted plywood behind my gauge. Improved it a bit.

 

[Poignard]

A piece of plywood painted with different coloured diagonal stripes

 

[bikedaft]

white paint behind as suggested

or i use on old rear view mirror from a car to quickly sight it. you could mount it somewhere i guess but i keep it handy for looking at back of engine etc

 

[NormanS]

It helps to change the plastic tube occasionally, because it does get stained after a while. I just use a torch.

 

[bristoljim]

A piece of plywood painted with different coloured diagonal stripes

+1 for parsifal's suggestion ,standard on steam boiler site glass's, you get a kink where the level is

Jim

 

[William_H]

Some safety standards for boats like our Fire and Safety checks will not allow the use of plastic tube for sight guage. This on the basis that in the case of a fire the plastic will melt releasing fuel to the fire wheras without the sight glass the tank can be isolated by a fuel shut off valve. Now this standard might not be a concern to you but would be an indication of good practice.
If possible I would seal off the outlets of the sight guage and make up a dip stick for a positive fuel quantity check. good luck olewill
good luck olewill

 

[NormanS]

Some safety standards for boats like our Fire and Safety checks will not allow the use of plastic tube for sight guage. This on the basis that in the case of a fire the plastic will melt releasing fuel to the fire wheras without the sight glass the tank can be isolated by a fuel shut off valve. Now this standard might not be a concern to you but would be an indication of good practice.
If possible I would seal off the outlets of the sight guage and make up a dip stick for a positive fuel quantity check. good luck olewill
good luck olewill

The best sight glasses are fitted with spring loaded normally closed valves, so that you only get a reading when you press the tit. Even if they're just fitted with a cock or gate valve, the maximum fuel to feed a fire would only be what was in the sight glass itself. Unless, of course you have a plastic tank......... Are plastic fuel tanks not allowed in Oz?

 

[LadyInBed]

I like the diagonal striped back panel.
I had the same problem, cleaning tube helped but the big difference came when I shone a red laser light on it, it made the fuel level quite easy to see.

 

[AntarcticPilot]

Some safety standards for boats like our Fire and Safety checks will not allow the use of plastic tube for sight guage. This on the basis that in the case of a fire the plastic will melt releasing fuel to the fire wheras without the sight glass the tank can be isolated by a fuel shut off valve. Now this standard might not be a concern to you but would be an indication of good practice.
If possible I would seal off the outlets of the sight guage and make up a dip stick for a positive fuel quantity check. good luck olewill
good luck olewill

While appreciating the cause for concern, a dip stick wouldn't be possible on mine; the filler hose has a bend, and the inspection hatch has about 8 bolts holding it down. So, if I don't use a sight tube, I'd have to invest in an expensive electrical fuel gauge (which would introduce its own set of hazards in the even of a short-circuit). My sight tube can be isolated readily (it doubles as a drain point, with a stop cock), and if fire reached that locker, it would already be out of control and I'd be abandoning ship rather than worrying about putting the fire out.

 

[AntarcticPilot]

I like the diagonal striped back panel.
I had the same problem, cleaning tube helped but the big difference came when I shone a red laser light on it, it made the fuel level quite easy to see.

The ideas like the diagonal strip or white paint behind the tube assume that the reading direction is normal to the tank wall. Sadly, it isn't on mine! The site-tube lives in a gap about 6 inches wide between the cockpit locker and the fuel tank, so the reading direction is parallel to the tank wall, and there's nothing behind it.

What I really need is a source of suitable coloured beads; if there's such a thing as a fluorescent one, that would be handy!

 

[NormanS]

I toyed with the idea of a coloured ball in a sight glass for my water tanks, but decided that I didn't want to take the risk of the ball going for a journey along the pipework.

 

[vyv_cox]

Have you seen the Truma gas level checker that I wrote about in YM? http://www.obelink.co.uk/car-caravan-accessories/gas/truma-levelcheck.html I used mine on the diesel tank and found it worked well for a steel tank but not for a plastic one. Not very cheap, although cheaper than a proper tank gauge, and it can be used for gas also.