Sight Glass ?s

Hey Guys,

I'm starting to think about my sight glasses for HLT and BK.

I've got 1/2" couplers in my kettles, and was thinking about simply using a 1/2" MPT x 1/2" tube swagelok elbow fitting. My question is will the swagelok get a good and watertight grip on the polycarbonate or Pyrex tube, or would a standard compression fitting with o-rings be best?

What is the general consensus on tube, polycarbonate, Pyrex, other? I plan to fashion a protective sleeve out of SS tube to cover the clear tube so I am not totally worried about fragility.

Thoughts?

Thanks,

Bryan

I used swagelock on mine but because the glasses were borsilite(sp) I swapped the crush ferrel with silicone orings. Works great.

Very nice, as I have the Swageloks on hand...

Where have you guys found to be the best source for the "Pyrex" glass, which I believe is the same as the boroscillate?

Thanks!

BK

You can get it from any place that sells art glass. You're looking for 12.7mm heavy wall SIMAX tubing. The wall thickness should be 2.7mm. Make sure you have them cut to length and flame polish the ends to keep them from chipping. Buy a couple extras.The orings you need are silicone #111.

Get the real glass tubing out of your mind if you don't have a plan for protecting it.

Bobby M,

If you don't mind me asking, what type of stores sell art glass? Online retailer? Was hoping to find something local to get the cuts and polish...

Thanks,

Bryan

Not every town has places that do this kind of thing. Phillyglassworks is one place I know of. Also, scientific/labwares type places may also stock SIMAX. This is probably one of those things you need to buy and have shipped.

If you use polycarbonate with a compression fitting then learn from my mistakes. Do not tighten too much or I guarantee the tube will shear at the fitting. Just tighten enough to make it snug and water tight!

I got a polycarb. sightglass from BobbyM. It has the swaglok fittings and silicone orings. It works great and doesn't take that much force to get it water tight.

I just ordered some of these polypropylene o-ring compression elbows from US Plastics and some polycarbonate tube from mcmaster.

We'll see how they work. Way better price than swagelocks.


http://www.usplastic.com/catalog/item.aspx?itemid=23261

Yeah, I guess it's important to mention it again. Whether you're using borosilicate or polycarbonate, it's not worth it to try using the metal ferrules in the compression fittings. A stack of 2-3 silicone orings are the ticket.

KiltedCorpse said:

I just ordered some of these polypropylene o-ring compression elbows from US Plastics and some polycarbonate tube from mcmaster.

We'll see how they work. Way better price than swagelocks.


http://www.usplastic.com/catalog/item.aspx?itemid=23261

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No doubt the price is right, but you'll need to be extremely careful with overheating. Most people have quite a bit of heat coming up the sides of the vessel and many of my past customers have had issues with boiling liquid inside the fitting and tube. Heat shields should be part of your design from day one.

Bobby_M said:

No doubt the price is right, but you'll need to be extremely careful with overheating. Most people have quite a bit of heat coming up the sides of the vessel and many of my past customers have had issues with boiling liquid inside the fitting and tube. Heat shields should be part of your design from day one.

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That would be true with these or swageloks. Though the swageloks wouldn't melt, buy the time you hit the melting point of the polypropylene, you'd already have boiling going on in your tube no matter what fitting you were using. A heat shield would be needed no matter what fitting you use if you are going propane. I'm going electric, so I won't have the heat issue.

I'm not saying that boiling the liquid in the fitting is the bad part, it's the overheating. You can get away with having the stainless fitting hit 250F (which is the limit on the polycarbonate). You'd hope that the boil in there would pull enough heat to keep from going over 212F, but it's not enough volume to do that.

I think it's a great, inexpensive solution for electrically fired vessels for sure. Maybe not so much for direct fired, unless you're careful.

are you pluging the top of the sight glass wth anything or do you leave it open to alow the air to escape?

You need to leave it open so the liquid travels up the tube. Think of a straw with your finger on it. Dunk it in liquid and that air is still trapped in the straw until you release your finger.

I almost ordered up a sight glass this week for my boil kettle, but after thinking about it for a bit, I decided I didn't want to take the chance of the high heat screwing with it.
Instead, I'm going to put markings on my 42" SS mash paddle and just use it as a dip stick. I'm still using a sight glass on the MLT, just not the boil kettle.

I am starting my keggle and for my sight glass I am wondering.

Should I weld a half inch T to my keggle, or should I weld in a coupling and then use a half inch nipple and then T.

The problem is I would like to have the coupling so I am not stuck with the T if I decide it doesn't work, but then I am worried with the coupling setup that my sight glass will far off the keg.

I am using the T for a thermocouple setup.

I agree that coupling, nipple, tee, thermo would be far off the keg. You're better off with two couplings.

I found an art glass shop in my town. Went down on my lunch break. Came away with 6 18" Pyrex tubes, which they cut to 18" for me, and torched the ends for $19.50. I was only going to get the 3 I need, but since it was so inexpensive I got 3 spares. They are 9.5mm OD tubes, with a really thick wall... probably 1/8". They fit the 3/8" Swagelok elbows I found on eBay perfectly.

is there much of a danger of sightglass tubing breaking, especially due to propane burner heat running up the sides of a keggle? i'm debating on if i want to install them in my kegs i'm currently cutting up, but haven't decided on it yet

Break during cleaning, That I've heard. During brewing? Not yet. If you use the borosilicate, it's much more likely.

diatonic said:

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That's a nice ass...