make a needle valve

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Ayay
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make a needle valve

Post by Ayay »

This uses a stainless bicycle spoke, 6mm copper tubing or a 'T' piece, and a bit of soldering with tin solder or silver brazing alloy.
needle valve design.jpg
needle valve design.jpg (9.29 KiB) Viewed 12756 times
Points to note:
There is no seal except for the threads at the top. A watertight seal is not essential as long as the brass nut is above the head; that is the highest level that the liquid can dam up to. In a reflux still it would be the level of the reflux outlet, and in a pot still it is the level in the lye arm where liquid runs back into the still if the valve is closed. (In case you want a valve in a pot still that is?)The height 'H' can be lengthened to get more head.

The outlet hole where the needle seats into must be a little smaller than the diameter of the needle. A standard bicycle spoke is 2.0mm, so the outlet hole needs to be 1.8mm. I think there are thicker spokes available for bikes, and even motorcycle spokes, so a bigger outlet hole can be used. I have found that a 1.8mm hole is enough for a steady dribble, I guess about 2 Litres per hour max - no promises though!

The needle point does not have to line up perfectly with the hole that it seats into - as long as you never open it far enough for the tip to get out of the hole, it will find it's way back in when you close it again. The length of spoke is springy and flexible.

The 'T' piece or tap handle at the top of the spoke must be soldered on to the threaded end. Careful to not let the solder run too far down the threads. If tin soldering eg with a soldering iron, the handle can be thicker so that a small hole can be drilled for the spoke end to fit into.

I have made a needle valve that uses the principles of the above design, but it is built into an existing bigger tap as a tap within a tap. Pics here: http://homedistiller.org/forum/viewtopi ... 3#p6772593
cornflakes...stripped and refluxed
punkin
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Re: make a needle valve

Post by punkin »

Brilliant idea and top post. I was very impressed with your fabrication in the other post, but this is more within my grasp.

Was thinking with a long spoke and the nut held above the inlet, i could incorporate this into a parrott for 4shots removal.

Are the spokes a standard thread do ya know?
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Husker
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Re: make a needle valve

Post by Husker »

I agree punkin. This is a nice idea that could help to avoid the costly $100 needle valve, but still provide a solution that is 100% lead and plastic free. You could even do away with the "brass nut", by simply using copper, and drilling and tapping the proper threads.

Total cost for this thing would be well under $5 (free if you can scrounge good enough).

H.
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punkin
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Re: make a needle valve

Post by punkin »

Husker wrote:I agree punkin. This is a nice idea that could help to avoid the costly $100 needle valve, but still provide a solution that is 100% lead and plastic free. You could even do away with the "brass nut", by simply using copper, and drilling and tapping the proper threads.

Total cost for this thing would be well under $5 (free if you can scrounge good enough).

H.

You could make it outa lead for all it matters (i was thinking of the original chromed nut the wheel has which must be the same thread) as it'd be well above the distillate in a supported arch or strut arrangement the way i was thinking of it. Held above the point the worm drips into the outlet by a couplea wires, thin strips of copper, or a couplea bits of brazing rod, with the spoke (valve bit) in the bottom of the bend.

I'm not good at explaining and i can't draw pics, so i guess i'll just have ta build it when i need my new parrot (jd bludged my last one outa me :roll: ).
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Tater
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Re: make a needle valve

Post by Tater »

that looks kinda like the piercing water line valve that's used to hook up ice makers in refrigerators== https://www.marinedepot.com/ps_ViewItem ... O1321.html" onclick="window.open(this.href);return false;" rel="nofollow
I use a pot still.Sometimes with a thumper
Ayay
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Re: make a needle valve

Post by Ayay »

punkin wrote:Are the spokes a standard thread do ya know?
I can't find a reference to what the thread size is. A bike mechanic should know.

Spoke nipples are about 10c and they are made of brass, every spoke should have one!
cornflakes...stripped and refluxed
Hack
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Re: make a needle valve

Post by Hack »

A long fine thread stainless steel screw would work for this as well. Then the thread is easy to identify.
Hawke
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Re: make a needle valve

Post by Hawke »

I can also see being able to build this using a 6mm refridgeration copper T. If you used a stainless screw instead of the spoke, it could also be scaled to other sizes.

edit: A motorcycle spoke could also be used. They are slightly larger and use stainless buds.
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Valved Reflux, 3"x54" Bok 'mini', 2 liebig based pots and the 'Blockhead' 60K btu propane heat
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