# Tube furnace tube-hose adapter



## goldandsilver123 (Nov 25, 2016)

Hello,

I just bought a tube furnace and I'm after corrosion (Cl2) resistant adapter between the hose(teflon) and the quartz tube.

I saw some custom made teflon adapter but the price is very high, there is some other alternative?

Thanks


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## Lou (Nov 25, 2016)

Can you provide pictures ?


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## goldandsilver123 (Dec 20, 2016)

Sorry for the delay, I was waiting for the tube to arrive, it took more time to arrive them the other company to build the furnace..

Here are the pictures: 

OD


ID


Furnace + tube


Furnace


At 1000 C



I can post more, if these one doesn't show what is needed to see.

The teflon tubing is 8 mm inside and 10 mm outside diameter


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## snoman701 (Dec 20, 2016)

Can you have a glass blower put a flange on the end of the pipe? Then you can easily use stainless and teflon sheet gasket...sealing either the inside or outside without is difficult due to cl gas.


Sent from my iPhone using Tapatalk


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## Lou (Dec 20, 2016)

Either what snowman said, or put a ground glass joint that is pyrex. Quartz doesn't conduct very well so you may be able to use pyrex at the ends if it sticks out far enough and the run times are days long.


Lou


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## goldandsilver123 (Dec 21, 2016)

My first idea was using a borosilcate ground joint, but I give up the idea when the company told me the prices to make any type of deformation or "solder" (fused silica-borosilicate). One joint costs about 3x the price of the 48 mm 600 mm quartz tube.

It was then when he told me about the teflon adapter, one costs about the same of 1 joint but if the tube breaks I don't have to pay again..

I think I will buy a PTFE bar and try to machine something out of it.

About the thermal conductivity, I touched one end of the quartz tube, out of curiosity, and it resembles more plastic than glass!


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## Lou (Dec 21, 2016)

Perhaps instead of a graded quartz to borosilicate butt weld on the tube, just have them grind the tube so that it is male-ended. Male ends help with dumping out the the contents.

Pyrex female ends ok.

Good job on the Pt bar!


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## goldandsilver123 (Dec 21, 2016)

Lou said:


> Perhaps instead of a graded quartz to borosilicate butt weld on the tube, just have them grind the tube so that it is male-ended. Male ends help with dumping out the the contents.
> 
> Pyrex female ends ok.
> 
> Good job on the Pt bar!




I will ask about the male ground joint, should be reasonable I think!

Thanks Lou, I really appreciate it!


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## snoman701 (Dec 22, 2016)

Grinding a joint on existing tubing will cost more. 

Lots of glass blowers are set up to do basic quartz work. Very few are set up to grind joints.

Having your ends flanged is going to be the cheapest option, long term. You'll make one set of stainless ends, the teflon gasket will be replaceable, and the quartz tube is also replaceable. 

A ground quartz joint will cost you about $50 bucks, probably another $100 to have it joined. Using a graded end just seems like an expensive way of doing it. Graded seals are more common when you only have one small part of an otherwise complex system that needs to be fused quartz.


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## Lou (Dec 22, 2016)

He's going to use chlorine.


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## anachronism (Dec 24, 2016)

snoman701 said:


> Grinding a joint on existing tubing will cost more.
> 
> Lots of glass blowers are set up to do basic quartz work. Very few are set up to grind joints.
> 
> ...



It's not always about the cheapest option, sometimes it's about the best long term option. Don't buy twice what you can buy once.


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## snoman701 (Dec 24, 2016)

What I was describing was not a wetted stainless part, it was using the stainless only as a system to join teflon sheet and glass. Similar to a triclover sanitary fitting. 

I completely agree in re: spending....and chlorine is not something I'd want to be skimpy about the sealing mechanism. Simply using a teflon "plug" seems a little scary to me. Putting pressure on a piece of glass tubing from the inside is always a bad idea, and from the outside is expensive due to the cost of the chunk of teflon needed....let alone the machining afterward.


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## goldandsilver123 (Dec 24, 2016)

snoman701 said:


> What I was describing was not a wetted stainless part, it was using the stainless only as a system to join teflon sheet and glass. Similar to a triclover sanitary fitting.
> 
> I completely agree in re: spending....and chlorine is not something I'd want to be skimpy about the sealing mechanism. Simply using a teflon "plug" seems a little scary to me. Putting pressure on a piece of glass tubing from the inside is always a bad idea, and from the outside is expensive due to the cost of the chunk of teflon needed....let alone the machining afterward.



There isn't going to be high pressure inside the tube, just enough pressure to push 5 cm of water column. I need to wait until the holidays are over to quote the male ground joint, this I think it's the best idea, then the teflon plug.


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