Vacuum booster vs. tubing

[tuolumne]

My son is contemplating a vacuum booster on one of our mainlines - we are going vacuum for the first time, so the bush is not set up that way - we'll make do with what we have for now. But my question is a little more theoretical than practical, but I'll describe the existing condition.

This is a 2500', 3/4" mainline with 900 taps (all 3/16" lines). The top 1500' of of the line has all of the taps and is consistently sloped around 5% with adequate side ties to keep it there. The lower 1000' gets a bit shallower and has some longer sections between ties where the slope can be very marginal when the line is full (which it often is!).

A 8"x18" booster (850 cubic inches of volume) could be easily put on the line near where the laterals stop coming in unless a different location makes more sense. That would be a bit over $220 with fittings.

But...for less money I could replace 100' of the 3/4" line with 2" pipe which is 3600 cubic inches of volume. How does this behave in comparison?

Or...for similar money I could add a 3/4" dry line for the first 500' - which does not seem like it would do much of anything.

Has anyone tried installing such a "linear" vacuum booster?

[sugaringman85]

Before considering a vacuum booster or adding 100' of 2' line. Consider at least a dry line. 1" dry line installed over the 3/4" line would be where I would start. From there I would consider the vacuum booster at the top end of that 1000'. That way when the 3/4" line is full, your still getting vacuum to the top of the 1000'. Even consider putting a manifold in at 1000' and another 1000' of 1" dry line so you get vacuum further up the hill. Do some research into line sizing and wet/dry systems. I think you'll find your answer there.

[DrTimPerkins]

Yes....this is good advice. Some people use boosters (a misnomer if there ever was one), but most have moved away from this and have gone to installing wet/dry lines. Cost is roughly comparable, but benefit is higher.

[tuolumne]

Yes, I understand that a complete dry line system is best. That will wait until the whole area gets reworked. My question is theoretical about what is happening in the booster vs. in a linear arrangement.

[GeneralStark]

I must be missing something here... what's the point of a booster without a wet and dry line running between it and your releaser?

In my experience boosters are used when there are many lateral mainlines converging with wet and dry conductors. From your description the issue you are trying to resolve is low slope and pooling of sap in the mainline. Yes, a larger pipe will better allow air to be removed from the system if the pipe is consistently sloped. A dry line above the wet line will also allow better air removal and if the wet line is frozen it provides an alternate route for the sap until the wet line thaws.

Without knowing what you are planning specifically for "adding vacuum" it's all kind of a shot in the dark anyway as how you are removing air from the system will impact how the system should be set up.

[Brian]

A booster is a pvc tank that looks close to abody of a releaser. You run a few main lines into it and have one big line leaving the booster to carry the sap down to the releaser. No manifolds and no two line system. If you are doing a bunch of diffrent sections this is ok like 3-5 hundred, after that you would have to run another single line from the release to the next booster and so on depending on line size and vac pump. The two line system(wet-dry) is way cheaper to run if you have 500 or more tap system to put in in my opinion and if sized right it will maintain better vacuum through the whole system.