vacuum gauge

[Big Stoney]

When using a gauge to check your vacuum on a 3/16" line should you have a separate gauge for each line or can you just use one gauge and check each line? Also, is there a good place to purchase the gauges?

[sugarsand]

Big Stoney, there are a lot of places to get vacuum gauges. I've bought them on the internet at 3 or 4 bucks each, about half of which were junk. FW Webbis supposed to have a good inexpensive gauge, thats where I plan to try next. Maybe others on here will suggestions also. I put a gauge on the upper end of every line, that way I can check most of them from the seat of my wheeler.

sugarsand

[unc23win]

You could do it either by having a gauge at every line or I guess you could use the same gauge if you made it easy to change. Although moving the same gauge might have you chasing your tail. I shopped around for gauges before I found best price for good gauges $6 from Lapiere dealer.

[morningstarfarm]

Go with webbs gauges..I have used them for years and they are around 5 bucks each...no probs yet...

[Big Stoney]

Thanks so much for the help. There is so much to learn and everyone's help is really appreciated.

[DrTimPerkins]

...should you have a separate gauge for each line or can you just use one gauge and check each line?

The most representative reading will be made by having a separate gauge for each line. If you allow air to bleed in, you're creating a vent (a huge leak) that will allow the sap to run out freely from the bottom of the line, thereby dropping your vacuum level. Same thing happens on a 5/16" pumped vacuum line, but in reverse. If you create a leak to check the vacuum, all the sap goes rushing out of the line, you put your gauge on it, and vacuum is really high. In actuality, it might be higher or lower than that reading depending upon the circumstances. You can move the gauge, but you have to have a way of doing it that won't let (much) air into the line when you change it over.

Please also note that most of these cheap gauges are +/- 4% FS, which means that the same gauge on the same line might read up to 2.4" Hg different. So don't spend a lot of time beating your head against the trees and tubing over trying to figure out why one line is getting 1" more vacuum than the one right next to it.....it probably isn't real.

[Biz]

Here's a funny story, I used 3/16 gravity tubing last season for the first time and bought some cheap gauges from ebay. One seemed to work OK and was accurate, about 15' of drop and reading 15" vacuum, but another one with similar drop never read more than a couple inches. Line ran really well so I thought it was a bad gauge.... until I was taking the lines down and heard a slight sucking sound. There was a slice in the tubing near the very end and leaking air in. The gauge was telling me something was wrong and I didn't listen to it!

Dave

[maple flats]

I have a gauge for the top of every line on 3/16 and top as well as bottom for the rest on vacuum. I hope my gauges prove good, they were about $4 ea. If they have a high failure rate, I'll be trying a bunch from Webb next.

[MISugarDaddy]

Where did you find Webb vacuum gauges for $5?
Gary

[JoeJ]

Just in case that there is some confusion about FW Webb vacuum gauges, FW Webb is a plumbing supply company located in 8 states (mostly in New England) with 35 locations. The vacuum gauge
from FW Webb that I have used for 3 years are the Westwood No S100-500 vacuum gauge that is 1/8". I looked up my invoice and they cost me $6.80. I have about 30 of these in my woods and have had only one fail in three years.

These vacuum gauges might vary slightly, but I am mostly using them at my main line intersections to check for vacuum leaks. Turn off the ball valve, watch the gauge for 10 seconds, if no drop in vacuum, move on to the next line. If the vacuum drops even the slightest amount in 10 seconds, there is a leak on that main line. Go find the leak.

Joe

[pdr]

Let's say I have a 3/16" line with 50' of drop and a leak somewhere in the lower few feet of that drop. I assume a gauge at the top will miss the leak because it will still indicate full vacuum. Any thoughts?

[Chicopee Sap Shack]

No you will still have lower vacuum at the top. You need a tight system from top to bottom. That leak at the bottom will allow air in the pipe and that will lower the total sap in he pipe that is making your vacuum


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[DrTimPerkins]

These vacuum gauges might vary slightly, but I am mostly using them at my main line intersections to check for vacuum leaks. Turn off the ball valve, watch the gauge for 10 seconds, if no drop in vacuum, move on to the next line.

That is a great example of a good use for these types of gauges. They'll give you a ballpark vacuum level, but are sensitive enough so a leak will show up quickly when used in this way.

[Super Sapper]

Let's say I have a 3/16" line with 50' of drop and a leak somewhere in the lower few feet of that drop. I assume a gauge at the top will miss the leak because it will still indicate full vacuum. Any thoughts?

You are right, as long as you have 30 feet of drop to the leak you will show max. vac. at the top if there are no other leaks.