VM Head Valve _Ball Valve ,Gate Valve _Verse butterfly Valve

[Kiwi-lembic]

Hi to all ,
Has anyone experimented with a butterfly valve concept in a (VM) vapour management head .. rather than the usual ball or gate valve sometimes mentioned .could this make a smoother path for vapour exits and have any other benifits that you could see ?

[rubber duck]

It's been talked about but to the best of my knowledge it has yet to be done. I think it might be over kill but someone would have to try it to know for sure.

[Kiwi-lembic]

kinda think thoses vapours will just slide on past that valve in any open state better than a ball cock or gate valve .and on full hearts take off speed .it might just be nice .it would be nice if automated... simple to accurately adjust , bouncin ideas around ..all good

[rad14701]

It is entirely possible to make a decent sealing butterfly valve for a VM take-off branch, but it must be made with precision... I have wanted to try making one for quite some time now and have a few ideas on how to go about making one... I started typing the steps out here but realized it was going to take far longer than I had expected so I'll try to post them later... I have only included the first ideas and perhaps the rest can be figured out without my input...

• Start with a scrap piece of copper the same size as the take-off branch
• Cut it at an angle several degrees off perpendicular (approximately .125"/2mm) a very short distance from the end. This will allow you to use this cut-off as a template for making the butterfly plate.
• Set the template, angled side down, on a flat piece of copper and scribe the outline of the inside of the template.
• Cut out the copper butterfly plate, leaving just enough excess copper to allow sanding and filing to an exact fit later on.
• Lot's more steps to follow...

[exon]

My count will show how new I am at all this.

I know nothing.

Well, that's not exactly true...

I do know I can not afford fancy stainless valves.

I've been working on a butterfly valve for VM, also.
Basically because I can't spring for the hi-dollar fittings!

I do NOT feel a perfect seal is required for a LM/VM setup.
Such a small amount of heavy vapor that may pass by a less than 100% perfect valve is IMO inconsequential to the process.
The reflux section should only be affected a very small amount, of course, depending on the margin of error in tolerance, which probably should be kept reasonable.

exon

[likkerluvver]

I bought a 1" SS gate valve on fleaBay last fall - ready for my future VM build. It does not have the circular disk valve that slides down (at 90 degrees to the flow) that I was expecting, but has a circular SS plunger that closes down on a seat which is 90 degrees to the flow. Not so good for unimpeded flow, but at least there is no plastic anywhere (except PTFE in the stuffing box seal).

I think the main advantage of gate valves is the fine control its design makes possible. - Each full rotation of the hand-wheel barely affects valve movement. Some sort of geared design where the first part of the valve opening is finely controlled would probably make both ball and butterfly valves more controllable. This relative lack of control is their main disadvantage.

Since I'm going to do a 3" build, I'm now wondering whether I should be looking for a 2" valve. - I'm in no hurry.

[exon]

THAT sounds like a neato valve, LL !

Does it have identification on it?

manufacturer and part number?

I'd like to see what it is...

Best
exon


...I just can't see where some amount of turbulence, induced at the location of a valve is all that critical in the process.
Some places within the device, it is said that the aim is stratification, and in others, turbulence is intentionally induced.

I have been advised, in the distant past, that vapor or liquid flow along the containment of the flow path is slowed, and is mainly within the central portion of the path. If so, some amount of obstruction is just not going to affect much, anyway.

When applying physics to generate our needs, we're never going to see a perfect-world scenario.
Cost effective is most likely the path we should choose, here on the hobby scale.

...I still can't afford the durned fitting!
exon

[Kiwi-lembic]

THAT sounds like a neato valve, LL !
Does it have identification on it?
manufacturer and part number?
I'd like to see what it is...
Bestexon

Sounds like a carburetor from a motorbike they got part numbers exon and wickedly easy control for automation
you could pull the butterfly choke valve on while ya equalising the column and compressing heads and then put the foot down and open the barrel slide when you hit the hearts lol
bet mulekicker would love this

[Prairiepiss]

Am I missing something? If you have a properly sized ball valve there would be no restriction. But a butterfly valve will always have a restriction in it. The butterfly itself would restrict flow. Being that the butterfly in the open position will be in the middle of the vapor path.

[exon]

I don't think you're missing anything, PP... Yet, I think the amount of restriction a butterfly valve would cause would be a minimal amount.
Of course, I know nothing....

Consider most pot stills shown in pics from around the globe... a substantial chimney coming up off the pot, then a very small vapor take off going to a thumper or even direct to the worm.

What I'd like to know is how to calculate the collapse of the vapor in a system, and it's diminished volume as it cools.
Got enGineers in the family tree... the part that DOES branch... I'll send out an email and see if any of them have a formula that could be applied to determine what rate vapor that is cooling, collapses in volume. Somewhere I recall a figure of 15"/second as the speed of the vapor... Is that correct?
...And we know the initial temp, and what temp we expect our pencil stream to be as it hits the parrot...

Now, I gotta go read more instructions so I can post a pic of this butterfly I've got under construction...
exon

This is a 1 1/2" butterfly valve under construction, for use on a 1 1/2 or 2" column.

I set up to make half a dozen of them, then already thought of a few improvements.