Shurflo vacuum design question

[82cabby]

Hi gang,

I am in the process of building my first vacuum system. It will have a Shurflo 4008 and a temperature controller for on/off, all built into a cooler…. My question is about connecting the incoming lines to the pump. I have 6 5/16 lines each of which has about 20 taps give or take. The lines all join at a ‘star’ connector which I usually connect right to the top of a 275 gal IBC tote. The tote is on a platform and star connector is about 5 feet above the ground.

Because I use 3/4” line and banjo cam locks to pump sap up the (big) hill, I have some extra 3/4” fittings and line.

What I would like to do is put a 3/4” cam locks on the star connector, the input and output of the vacuum, and on the top of the tote. Then on days when I want the vacuum I can run lines from the star connection to the vacuum setup and from there to the tank. And on days I need to bypass the vacuum I can just connect the star fitting straight to the top of the tank.

My question is about the lines connecting the star to the vacuum and the vacuum to the tank. The easiest place for the vacuum setup to sit is on the ground beside the tank. This is about 6 feet almost straight down from the star fitting.

A) will I end up getting some sort of air lock with a vertical drop right before the pump? I’m worried it won’t be able to clear the inevitable bubbles in the line.

B)What size line should I use to connect the star fitting to the pump? I guess the obvious options are 3/4” which I have kicking around. Or 3/8” which is the size that the pump will be plumbed with. But really I could use anything.

C) I guess I could put the vacuum setup on top of the tote and minimize the vertical drop, but that would make it tough to access.

Any feedback is appreciated!

[SeanD]

I tried to put responses into your questions below, but MT is giving me a little trouble with it. Sorry if it is confusing to read.

A) will I end up getting some sort of air lock with a vertical drop right before the pump? I’m worried it won’t be able to clear the inevitable bubbles in the line.

I can't speak to the air lock from a vertical drop, but if you do anticipate one, can you slope the incoming lines to the vac box and not to the top of the tank. Then when you disconnect and switch to gravity, you can just lift the disconnected end where your star fitting is and lift up into the opening of the tank.

B)What size line should I use to connect the star fitting to the pump? I guess the obvious options are 3/4” which I have kicking around. Or 3/8” which is the size that the pump will be plumbed with. But really I could use anything.

My Shurflos use 1/2" fittings. I have 3/4" mainlines coming in, so I have a reducer right at the input to the pump. I try to leave as much space for air/sap exchange as possible. Before switching to a mainlines, I made a simple manifold out of a couple feet of 3/4" and had saddles run into it. I could remove it with cam locks as needed. Sounds a bit like your star fitting idea - only I didn't have that fitting.


C) I guess I could put the vacuum setup on top of the tote and minimize the vertical drop, but that would make it tough to access.

It's a tradeoff. If you have the pump pumping sap up 6' to the top of the tank, you will lose some vac on the side coming in. Those little pumps can only do so much. That said, I have my vac boxes below my tank like that in two spots with no ill effects. One has 30+ taps and the other has 155+ taps. In those spots, it's a million times easier to access the box and improve the overall slope of the mainline to drop them down below the top of the tank. When everything is tight, I'll still get 25-27". You could try to split the difference and put the box on a small stand low enough for you to get into it easily, but higher off the ground so the pump does not have to lift the full height. Or, put the box on the top of the tank and build a stand or have a simple step ladder to give you access to the box. I did that before.

[82cabby]

Thank you! I really appreciate your help. That’s a good point about having to pump up 6 feet so I’m going to see what I can do to build some kind of stand to at least get the vacuum setup a bit higher. I could probably get it 3’ higher pretty easily. I’ve progressed to having the electronics all working now it’s time to build all the plumbing aspects of the project.

[82cabby]

Got the unit finally finished today (except for the heater, still working on that). Ran a test in the kitchen using a clean pot of water and it is sucking air badly somewhere.

Sigh…. Looks like tomorrow is trouble shooting day…..at least the electronics seem to work.

[82cabby]

Easiest troubleshooting ever. The cover on the strainer was loose and drawing in tons of air. Fixed!

[SeanD]

Get rid of the strainer. You'll get more headaches from that part than any other. The screen clogs too easily with gunk during warm spells, it's very easy to mess up the threads and gasket when putting it back on, and the plastic cap cracks easily. It's not worth any potential benefit of screening ice out.

[mainebackswoodssyrup]

We also have removed the screens from our Shurflo setups. They will plug and you never know when it could happen. Have not had any diaphragm issues in doing so. But yes- first spot to check for a leak with a Shurflo is the filter/strainer. Leaks develop easily if the gasket isn't set right.

[82cabby]

Hmmm. That’s a thought. I was considering moving the strainer from inside the cooler to outside so I could see/clean it more easily.