Vm/Lm reducer or full bore

[Muddydisco]

I'm just starting on building a combo vm/lm head. 54mm column 1.2m tall, boka slant plates and a VM take off t just below.
Having looked at several posts on HD and on here. I'm lost as to wether to have the T as a reducer or go full bore of the column and reduce at the gate valve?
What's the general consensus? What's the theory behind it?
Many thanks
Nick

[Yummyrum]

Geday Muddydisco

The theory is that the minimum reflux ratio is determined by the ratio of the diameter of the column to the diameter of the opening.
So if you stick a 2" gate valve on a 2" pipe,you will have a 1:1 reflux ratio when the gate valve is wide open .

Now the practicalities of it all .....
First off 2" gate valves are fucken expensive compared to say 3/4" or 1"

Also unless you are going to use your VM as a stripper,yopu will never run at 1:1 reflux ....typically around 5:1 to 10:1 as the whole Idea of having a VM is to produce High AVB Booze

So the reason for the reducer is that you can reduce the effective column diameter and connect to a cheap Valve and still get the low reflux ratio if you want.

Having said all that,there are many guys using 2" colunm with 1" or less valves attached and do just fine .

I built mine with a reducer but have never run with my valve more than halve open if that.

Hope that helps a bit .

[Yummyrum]

Geday Muddydisco

The theory is that the minimum reflux ratio is determined by the ratio of the diameter of the column to the diameter of the opening.
So if you stick a 2" gate valve on a 2" pipe,you will have a 1:1 reflux ratio when the gate valve is wide open .

Now the practicalities of it all .....
First off 2" gate valves are fucken expensive compared to say 3/4" or 1"

Also unless you are going to use your VM as a stripper,yopu will never run at 1:1 reflux ....typically around 5:1 to 10:1 as the whole Idea of having a VM is to produce High AVB Booze

So the reason for the reducer is that you can reduce the effective column diameter and connect to a cheap Valve and still get the low reflux ratio if you want.

Having said all that,there are many guys using 2" colunm with 1" or less valves attached and do just fine .

I built mine with a reducer but have never run with my valve more than halve open if that.

Stillin Pics 035.jpg

Hope that helps a bit .

[Muddydisco]

Definitely never doing stripping runs with it.
And get the reasoning behind the gate valve sizing. But I'm seeing builds where the actual column is reduced in size before the boka head. This is what's confusing me.
So they have a 54mm column to a 28mm tee then the boka head is 54mm again. With the VM take off 28mm and gate valve.

Then other builds where the column and boka are 54mm all the way and the 54mm take off is reduced to a 28mm gate valve.

Are they both acceptable or is one more beneficial than the other?

Edit your pic has just come up. Now what's the pipe connecting the head to the column for?
Have you a build thread?

[Muddydisco]

Found your build :)
Also now seeing the reasons for the external pipe.

Also found some comments re 2" boka speed vs 3" speed

So now thinking do I change to 3".

Every time I get one thing straight another things comes to mess me up.

So many choices....

[MacStill]

So many choices....

here's another choice :handgestures-thumbupleft:

[Muddydisco]

Shipping is the killer on that one. More than the still itself ;)

[MacStill]

Shipping is the killer on that one. More than the still itself ;)

If your profile was filled out I would've known that :teasing-neener:

[Muddydisco]

Sorry I thought it was :( done now boss :)

I'm sticking with my plan takeoff speed vs cost.
If I start with a 2" and a smaller boiler, I can manage the times. If I get the urge to go large I can then build both bigger.