VM build - critique please

[needmorstuff]

Hi All,

I have a bunch of threads open at the moment and have received much help. That has lead me to this crude diagram of what I hope will be my first build. I wondered if you could critique it for me before I start ordering the parts.

[ShineRunner]

Condenser controlled VM. No expensive valve. No figuring out how to connect your gate valve to the column. Too easy... You’re already planning the corrugated SS REflux condenser- just use that as your gate.
viewtopic.php?f=1&t=41579

SR

[needmorstuff]

I have read DADs thread a bunch of times. I am sure it works for lots of people but I'd rather just have a valve.

[bluefish_dist]

Looks like it should work fine. if you need more height, I made a T style condenser which saves a lot of height. Just take a T and slice it a little so you can bend the ends up about 5 deg making it more of a V or banana at the top. Then feed in the CSST condenser.

The valve offers more fine adjustment than a sliding condenser. The plus of a ccvm is cheap, quick and easy. What you are building is a little more time to build, but may be a little nicer in the end.

[ShineRunner]

Sure thing. You asked for a critique and I wasn’t sure that you had seen the ccvm threads.

Good luck

SR

[needmorstuff]

thanks, it is a good shout as getting a none brass gate valve connected cost effectively is a task in itself.

[bluefish_dist]

Valve is pretty easy to connect. They are threaded, if using copper you can buy an adaptor with threads on one end and solder on the other. If using tri clamps, just buy some threaded tri clamp adapters. Works fine up to 2". Beyond that size, it gets tougher.

[needmorstuff]

this 76mm equal tee - it says it must be brazed and soft soldering not permitted! is that just covering their back? is soft soldering ok for 76mm equal tees?

https://www.bes.co.uk/end-feed-equal-tee-76mm-22231" onclick="window.open(this.href);return false;" rel="nofollow

[kimbodious]

I'd suggest a sight glass below the takeoff. I used to run a VM. I strongly recommend you try the CCVM option first; you can always put a valve in later. The money saved by not having a valve will just about cover the cost of the sight glass

[needmorstuff]

I am considering a sight glass.. re the valve.. already bought it.

was thinking about this for a cheap sight glass, cut hold in 3" copper before Tee insert fitting, mark it and cut then solder in place - https://www.ebay.co.uk/itm/Sight-Glass- ... 1438.l2649" onclick="window.open(this.href);return false;" rel="nofollow

[needmorstuff]

all bits ordered.. hopefully I will have things to get on with at the weekend should they arrive.

[der wo]

There are rules for plumbers, for example you have to braze gas lines, but to solder water lines. Or soldering is only allowed up to a certain diameter. Those rules can vary in each country.
That's all. Our stills are not so critical. You can do what you want.

Like always glass to copper will have a sealing between. Probably the sealing is not PTFE. I would try to cancel the buy and first try it without sight glass. Or try to replace the plastic with PTFE.

[needmorstuff]

There are rules for plumbers, for example you have to braze gas lines, but to solder water lines. Or soldering is only allowed up to a certain diameter. Those rules can vary in each country.
That's all. Our stills are not so critical. You can do what you want.

Like always glass to copper will have a sealing between. Probably the sealing is not PTFE. I would try to cancel the buy and first try it without sight glass. Or try to replace the plastic with PTFE.

In the end I didn't get the sight glass. Figure I would try run it without, I mean the only reason to have it (apart from looking cool) is to check for column flooding - I read that the column will make a "singing noise" when that happens so I am hopeful I can run it without.

If it is needed I can always retrofit.

Soft soldering it is then! I had planned on doing that but it's good to have my thoughts ratified. thanks again.

[der wo]

With 3" and 4kW you will only have flooding when using a packing retainer with small holes. There are a few threads about it.

I would say it makes a gurgling sound.

[needmorstuff]

With 3" and 4kW you will only have flooding when using a packing retainer with small holes. There are a few threads about it.

I would say it makes a gurgling sound.

by packing retainer do you mean the thing in the bottom of the column stopping the packing falling into the boiler? I was planning on using a few scrubbies - and the packing is SPP. The boiler is a keg with a 2" ferrule - so I have a 2" to 3" adaptor at the bottom so hopefully that will provide a good amount of friction/choke point for the scrubbies

[der wo]

In the threads I remember they used a stilldragon filter disc for retaining the packing.

I don't have a 3" with 2" connector. I think scrubbies will be all fine. You will see. Assemble it, fill it with packing and shake it a bit, then you will see, if you can trust it.

An easy fix would be a few copper wires bend or soldered to something like a tic tac toe cross. Place it in the 3"-2" reducer, lay a scrubbie on it and then fill in the packing. The reducer is the retainer for the cross, the cross the retainer for the scrubbie, the scrubbie the retainer for the SPP.

[needmorstuff]

could get some of this - 11.1mm holes.. 15x15cm sheet - very cheap - make a disc to sit inside the 2" to 3" keg adaptor, then scrubbies on top.
https://www.ebay.co.uk/itm/STAINLESS-ST ... 1198345904" onclick="window.open(this.href);return false;" rel="nofollow

[der wo]

Yes. But I think no need to spend money if you have a piece of wire at home.

[needmorstuff]

I don't have anything of a decent thickness to be honest. In terms of the build cost this is very small.. I'll get it just in case

[needmorstuff]

on another note, I was planning on soldering a piece of 6mm copper pipe in the top the TEE on the takeoff arm.. for a thermometer. Would it be best to solder the end of the tube that is inside the still? or leave it open so the thermo probe is in direct contact with the vapours?

and - is there another location for a thermoprobe that is of great benefit?

[der wo]

The probe should be directly in the vapor. Edit: And not in contact to the copper. A layer of PTFE around the probe is a good insulaton to the pipe. There is no pressure. You simply can solder a thin tube into the tee, stick the probe into, seal with a bit PTFE tape.
Most important is that the probe doesn't get in contact to the reflux. So use the horizontal path of the Tee for placing the probe. And bent/position your reflux condensor in a way, that the reflux falls down centered. Not to the column wall and then into the horizontal path of the tee to the probe (worst case).

That's enough for the beginning. Later if you know what you want, perhaps you want a second thermometer. In the wash to monitor the heating up. Or somewhere in the middle of the packing: Something like "If I here hit azeo, then it's really clean a half meter upwards."

[needmorstuff]

thanks. it will go in the horizontal. good point on the reflux condensor. I will bends it so it's got a "cold finger" type section at the bottom and make sure it's centred and definitely away from the horizontal opening of the tee

[needmorstuff]

another question...

I have 2 end feed reducers.. to get me from 76mm down to 28mm. The first is 76 to 42, then second is 42 to 28.

When soldering multiple end feed reducers together is it best to first do the small one and let it cool.. then do the big side? or get everything clean and fluxed and do both joints at the same time as the fittings will be hot anyway..

I have that one and another to do to go for.. from 28mm down to 15mm then a 90 degree bend into 15mm liebig so the principal will be the same I guess.

[Expat]

So long as everything sits well together, solder them all at the same time.

[needmorstuff]

thanks.

[der wo]

I hope you ordered the right fittings. Reducer fittings will have always a female end on the small side. But there are two versions of the large side. And the connections of the Tee are always female. So in your case both reducers must be male on the large side.
In this case you could solder it at once, because the best solder position is for both solderings the same: Position it vertical and the small reducer on the bottom, then the large reducer, then the tee. Otherwise solder could flow into the pipes and that's hard to clean out.
You could also already solder the 28mm pipe into the small reducer.
But I personally don't like it this way. I would begin with the largest diameter piece (the tee) and then add the smaller pieces one at a time. Smaller connections don't need as much heat. It's not very likely, that a larger connection melts when soldering a small one besides to it.

[needmorstuff]

I think so - they fit together.. so of doing all at once do it upside down? or in any case do it upside down? so the solder doesn't flow into the inside of the pipe?

[der wo]

I also thought it would fit, because the male end ones are a bit cheaper normally. And of course you would choose the cheap ones.
But for example for the reducer to the KEG you need the female one.

[needmorstuff]

You know me already

Yes for the keg adaptor it is definitely female.. I have bought an adaptor that someone has made up - you fit the 76mm pipe straight into it. However (isn't there always a BUT) the ferrule seems to be brass so I will have to Tin that also

https://www.ebay.co.uk/itm/173127369000" onclick="window.open(this.href);return false;" rel="nofollow

For the price of the reducer and the ferrule there wasn't a great deal in buying separate and buying this made one so I got the made one.

I am a bit concerned about tinning it though.. as when I heat it up to tin I an thinking the solder between the ferrule and reduced will soften.

[OtisT]

Hi Needmorestuff. I have a few VM columns and love them. These are just my opinions and preferences.

1) Consider splitting the column for your convenience. Make a shorter column head and have a 35ish" column extension for when you need to fraction. I have found that 95% of the time I don't need a tall of a column, and it's much easier to work with when short. On my short VM column head I left 8" below the vapor port so that I could put in a role of mesh and get some reflux when needed (compressing fores/heads mostly). Just my preference.

2) Swap the side that your VM port/product condenser are on from the right to the left. i.e. They should be on the left, as you look at the still. Why? Your valve is attached via threads. When your liebig is slanted, gravity wants to pull it down. With a VM port on the left and liebig pointing toward the you, gravity is working to keep it tightened. On the right, gravity wants to loosen the joint. This don't matter so much on a new still, but after removing/attaching the valve a few times, it can become an issue.

3) I noticed a section of pipe between your column vapor port and the valve that may be unnecessary. Although you may want to have your liebig extend beyond the edge of your keg when it's pointed straight down, it's not necessary because you run a liebig slanted. That pipe section will likely be your weakest point on the horizintal and I am simply concerned with the overall extension of your horizontal section. Maybe consider w/o the extension.

Good Luck. Otis