Method to allow reading sight glass below bottom of glass ?

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DeafSmith

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I've bought a couple of sight glass/thermometer kits for installation on a cooler and a kettle and I'm a little disappointed in how much water is needed in the vessel before the level is even readable on the sight glass. So I had an idea - I couldn't find anything searching for this, but surely someone here has tried it. I'm going to do some tests this weekend, but thought I'd post it here and maybe save myself some trouble if it has been tried before.

The problem, as you know is the height that the fittings take up above the "T" coming out of the cooler/kettle. So what if I cut the sight glass say about a half inch above the top of the fitting, slipped a piece of silicone tubing over that stub, then connected the other end of the tubing to the bottom of a long straight piece of polycarbonate tubing which would serve as the sight glass? The bottom of the long piece would be even with the "T" coming out of the cooler or kettle. I'd think the siphon effect would keep the level in the glass even with the liquid level in the vessel, even after the level gets below the "hump" in the tubing. Of course, I'd have to figure a way to mount the long sight glass beside the "T". I plan to use this only for a cooler HLT and a kettle to be used only for heating strike and sparge water, so wouldn't expect steam bubbles to be a problem.

Anyone tried this already or know for sure that it wouldn't work?
 
I haven't tried that method, but if you're doing an electric rig you could have a street elbow come off the bottom of the vessel and then hook up the sight gauge. You could even add a petcock drain inline if you wanted to drain that last little bit out.
 
I've bought a couple of sight glass/thermometer kits for installation on a cooler and a kettle and I'm a little disappointed in how much water is needed in the vessel before the level is even readable on the sight glass. So I had an idea - I couldn't find anything searching for this, but surely someone here has tried it. I'm going to do some tests this weekend, but thought I'd post it here and maybe save myself some trouble if it has been tried before.

The problem, as you know is the height that the fittings take up above the "T" coming out of the cooler/kettle. So what if I cut the sight glass say about a half inch above the top of the fitting, slipped a piece of silicone tubing over that stub, then connected the other end of the tubing to the bottom of a long straight piece of polycarbonate tubing which would serve as the sight glass? The bottom of the long piece would be even with the "T" coming out of the cooler or kettle. I'd think the siphon effect would keep the level in the glass even with the liquid level in the vessel, even after the level gets below the "hump" in the tubing. Of course, I'd have to figure a way to mount the long sight glass beside the "T". I plan to use this only for a cooler HLT and a kettle to be used only for heating strike and sparge water, so wouldn't expect steam bubbles to be a problem.

Anyone tried this already or know for sure that it wouldn't work?

If I'm understanding your intention, you are describing a "trap" used in pluming and it won't work as you hope.

A trap, like the one on a sink, or built into a toilet, will fill up when liquid passes through, but won't empty when the level of the fluid drops on either side. They are intended to block gases from coming back through the plumbing.

Maybe I'm not getting your concept right... a sketch would help.

Edit... If you are using a "tee", you can turn the tee another 90 degrees and us an elbow npt to compression fitting instead of a straight npt to compression fitting which might help you read a bit lower in the kettle.
 
Isn't there a concern with trying to get accurate hydrometer readings at mash temperature? I know you can do a temperature correction, but how far do the readings deviate when you get up to 150+ degree range? Also, will the glass withstand that?

Or are you planning on capturing and then cooling to the appropriate temp?

Not doubting your idea in any way. Just pointing out what would be my concern.
 
ScubaSteve - this is a combination sight gauge and thermometer which I have already purchased, so trying to use what I have.

Ohio-Ed - what I was describing is just placing a vertical polycarbonate tube next to the Tee with the bottom of the tube about even with the Tee. The old sight glass would be cut off about a half inch above where it comes out of the fitting. A flexible tube would then connect the stub of the old glass to the bottom of the new sight glass. There would be sort of a reverse trap (going up instead of down) between the two. But I like your idea of turning it sideways - that doesn't completely solve the problem, because I still have some fittings rising up above the level of the Tee, but it would help. Maybe I could turn it sideways, cut the old tube to leave a stub coming out sideways, then have the vertical glass connected with a piece of flexible tubing to the stub - this eliminates the "trap" and puts the bottom of the glass just barely above the Tee.

JetSmooth - I'm not sure what you're getting at - this doesn't involve a hydrometer at all. ??
 
ScubaSteve - this is a combination sight gauge and thermometer which I have already purchased, so trying to use what I have.

Ohio-Ed - what I was describing is just placing a vertical polycarbonate tube next to the Tee with the bottom of the tube about even with the Tee. The old sight glass would be cut off about a half inch above where it comes out of the fitting. A flexible tube would then connect the stub of the old glass to the bottom of the new sight glass. There would be sort of a reverse trap (going up instead of down) between the two. But I like your idea of turning it sideways - that doesn't completely solve the problem, because I still have some fittings rising up above the level of the Tee, but it would help. Maybe I could turn it sideways, cut the old tube to leave a stub coming out sideways, then have the vertical glass connected with a piece of flexible tubing to the stub - this eliminates the "trap" and puts the bottom of the glass just barely above the Tee.

JetSmooth - I'm not sure what you're getting at - this doesn't involve a hydrometer at all. ??

Connecting the top of the "stub" to the bottom of the new tube is going to cause the flexible tube to be shaped like a sideways "S"... which will create a trap. If you don't form an "S", then I don't see how it would read any lower then the top of your fitting.

Rotating the "T" and using an elbow might gain you 1/4" - 1/2" of "readable" tube.

I just make sure that I have plenty of liquid in the "measurable" range. I can read down to about 2.5 gallons. So if I need 3 gallons of hot water... I fill my hlt to about 6 gallons to start with... anything left gets used for cleanup. Only downside is it might take a bit longer to get the water ready.

If you use a siphon tube in your kettle, you have a similar issue if you try to stop draining and restart after the fluid level is below the valve... unless you have liqiuid in a connected hose to restart the siphon, your stuck.
 
Connecting the top of the "stub" to the bottom of the new tube is going to cause the flexible tube to be shaped like a sideways "S"... which will create a trap. If you don't form an "S", then I don't see how it would read any lower then the top of your fitting.

Rotating the "T" and using an elbow might gain you 1/4" - 1/2" of "readable" tube.

I just make sure that I have plenty of liquid in the "measurable" range. I can read down to about 2.5 gallons. So if I need 3 gallons of hot water... I fill my hlt to about 6 gallons to start with... anything left gets used for cleanup. Only downside is it might take a bit longer to get the water ready.

If you use a siphon tube in your kettle, you have a similar issue if you try to stop draining and restart after the fluid level is below the valve... unless you have liqiuid in a connected hose to restart the siphon, your stuck.


My HLT is a 5 gallon cooler (I don't plan on doing more than 5 gallon batches), so I need to use all the water down to the hole where the Tee comes out of the cooler. The Tee for the sight glass/thermo is mounted at the same height as the ball valve drain. The sight glass that I have has the bottom of the clear tube about 2 1/4 inches above the center line of the Tee, or 2 1/2 inches above the bottom of the Tee (last usable water level with no siphon tube inside the HLT). 2 1/2 inches is too much to waste in a 5 gallon cooler. I think that by cutting the sight glass tube off, leaving a stub, then turning the Tee so that the stub comes out horizontally, or even pointing down by 30 or 45 degrees below horizontal, and then connecting that by tubing to the vertically mounted section (the cut off piece) which has its bottom even with the bottom of the Tee, that I will be able to see the water level all the way down to the bottom of the Tee, which means I only have about 1/3 to 1/2 gallon unusable water below the bottom of the Tee (and also below the bottom of the ball valve outlet). I'm not going to try to use a siphon tube inside the HLT to drain below the ball valve.
 
Okay. I'm a moron, apparently. Either that, or I shouldn't forum browse and work at the same time. Somehow, I got it stuck in my head that you were looking to suspend a hydrometer in your sightglass so you could monitor gravity during the boil.

*smacks head*

Read your OP again and now I get what you're aiming at. Haha.
 
Okay. I'm a moron, apparently. Either that, or I shouldn't forum browse and work at the same time. Somehow, I got it stuck in my head that you were looking to suspend a hydrometer in your sightglass so you could monitor gravity during the boil.

Got your mind on planning your weekend ? :D
 
My HLT is a 5 gallon cooler (I don't plan on doing more than 5 gallon batches), so I need to use all the water down to the hole where the Tee comes out of the cooler. The Tee for the sight glass/thermo is mounted at the same height as the ball valve drain. The sight glass that I have has the bottom of the clear tube about 2 1/4 inches above the center line of the Tee, or 2 1/2 inches above the bottom of the Tee (last usable water level with no siphon tube inside the HLT). 2 1/2 inches is too much to waste in a 5 gallon cooler. I think that by cutting the sight glass tube off, leaving a stub, then turning the Tee so that the stub comes out horizontally, or even pointing down by 30 or 45 degrees below horizontal, and then connecting that by tubing to the vertically mounted section (the cut off piece) which has its bottom even with the bottom of the Tee, that I will be able to see the water level all the way down to the bottom of the Tee, which means I only have about 1/3 to 1/2 gallon unusable water below the bottom of the Tee (and also below the bottom of the ball valve outlet). I'm not going to try to use a siphon tube inside the HLT to drain below the ball valve.

I did something similar, but instead of cutting the tubing and connecting it with tubing, I just bent the (polycarbonate) tubing (from Bargain Fittings) at 90 degrees, to connect it to the T which comes out sideways . You have to be careful heating it up to bend it, and will very possibly screw up the first attempt.

This does give another gallon or so of measuring capacity in a keggle.
 
I did something similar, but instead of cutting the tubing and connecting it with tubing, I just bent the (polycarbonate) tubing (from Bargain Fittings) at 90 degrees, to connect it to the T which comes out sideways . You have to be careful heating it up to bend it, and will very possibly screw up the first attempt.

This does give another gallon or so of measuring capacity in a keggle.

That's an interesting idea. What did you use to heat the tubing? What radius bend? Was the bend a full 90 degrees?
 
I used a propane torch. The bend is a full 90, and is pretty tight, with a radius of less than an inch.
 
Correct, some kits read lower than others depending on the fitting thread size and how the tubing is connected to the fittings. The only other way to get it reading lower is to have the tee's sight port turned to horizontal. Putting an elbow compression fitting in here is one way, or bending the polycarb as mentioned.
 
One other possible method I thought of - using a float ball in the tube like you see in some coffee makers, except instead of a ball, have a long, slender tube as the float - at minimum liquid level, the bottom of the float would be invisible, but the top would stick up far enough to be seen - use the top to indicate the level. One problem I can see (besides finding something to use as the float) is that the float would have to be so light that as the liquid level falls, surface tension might stick the float to the inside of the polycarbonate tube, not allowing it to drop as the level falls. Might be better to use a ball on bottom and top connected by a very thin rod to minimize contact with the walls of the tube? I have no idea what to use as the float, but it would be interesting to see if this would really work.
 
Even if you start measuring at 2 gallons for example, you will need more water than that to mash in, so it's not really and issue. If you have ten gallons of water in your HLT to start with, pay attention to how mush your removing from the HLT to the mash tun. A brew calculator will estimate how much water you need for x amount of grain including the absorption rate.
 
I made a dip tube inside the HLT to the bottom and then filled with water above the level needed to siphon and let the water run out. after water ran out I added a measured amount of water and my first mark was 10 Liters and every five Liters after that. My fitting is about 4" from bottom of keg. This was the best thing I could think of doing anyway!:D
 
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