Tubing venting

[richwilly]

Thought i read somewhere not to vent gravity lines.just out of curiosity i vented end of runs and seem to get more flow.any thoughts?

[psparr]

You will get more flow until the added bacteria close the hole sooner. It has been studied and proven venting produces less sap overall.

[GeneralStark]

Do some searching here as to the why, but I can also save you some time by saying....don't vent your lines.

[DrTimPerkins]

Thought i read somewhere not to vent gravity lines.just out of curiosity i vented end of runs and seem to get more flow.any thoughts?

When you put in a vent, the sap that is in the line suddenly runs out very fast because it is no longer held in the line by capillarity. However it will very quickly stop, and you will end up with one drip in, one drop out. More importantly, by introducing microbes into the system through the vent, you will end up with far less sap at the end of the season due to taphole drying. So basically your choice is to get your sap really fast for a short period of time (minutes), or to get FAR more over the season. Most people choose to NOT VENT and go with the "more sap" is better.

[dirtnworm]

I am wondering about my system too. All on gravity with 1/2" main and 5/16" laterals and drops. All are full of sap but I'm not seeing much flow into barrel. I have around 2% slope. I'm about to go back to buckets cause I am stumped.

[Cody]

Try a shurflo pump on end of mainline into collection point,or if you have slope 3/16 line.Since you have it up I would try the shurflo pump.Allot of info on these pumps can be found in here.

[dirtnworm]

run the pump all the time? or once a day? I would have to haul a generator out there.

[DrTimPerkins]

I am wondering about my system too. All on gravity with 1/2" main and 5/16" laterals and drops. All are full of sap but I'm not seeing much flow into barrel. I have around 2% slope. I'm about to go back to buckets cause I am stumped.

It isn't a real problem if your laterals have sap in them, but they do need some slope to avoid building up back-pressure and reducing flow. However if your mainlines are truly full of sap and not running, they are not sloped properly. Mainlines should drain freely. On such low slope, you have to be very careful and use a level to ensure they do have some slope on them.

[Cody]

12 volt deep cycle battery.Turn it off at night when freezes.

[dirtnworm]

Great, thanks for the info. I will check my slope and ensure the mainline is full of sap. Forgot to mention I'm using 6 way star fittings on mainline. I should have done more research, seems like everyone else is using saddles on gravity systems.
thanks

[DrTimPerkins]

Great, thanks for the info. I will check my slope and ensure the mainline is full of sap.

Hopefully you mean ensure the mainline is NOT full of sap.

[dirtnworm]

Well you have me thinking maybe my slope is not enough and my mainline is probably full. If that's the case hopefully I can adjust my slope to fix the issue.

[dirtnworm]

So I checked the slope and for the most part I have over 3 percent. Close to the collection point it does level out around 2 percent. maybe a little less. the mainline was empty when I checked today and the laterals were full. So I guess we'll see when we get above freezing.

[mapleack]

So I checked the slope and for the most part I have over 3 percent. Close to the collection point it does level out around 2 percent. maybe a little less. the mainline was empty when I checked today and the laterals were full. So I guess we'll see when we get above freezing. Dirtworm, gravity laterals need to have slope as well, no low spots, more slope the better. As long as they are sloped do not worry about sap being "backed up" remember you are only looking at a snapshot in time, not the sap total at the end of the season. The 6 way stars are "ok" for gravity, however they are usually only in a convenient spot for maybe two laterals. You end up running more lateral tubing just to reach a star with a couple more lines. If you do the math on the cost of tubing per foot compared to the cost of saddles you'll find that something like an extra 15 feet of tubing ends up being the same as a saddle, so then you're better off with saddles. When you have vacuum, separate saddles are a necessity so you can isolate leaks and also so a leak in one lateral doesn't negatively impact vacuum in another lateral. I've been down this whole road in the last 30 years, vented gravity tubing on the ground, aerial tubing that looked full going into star fittings and now high vac with everything to individual saddles. Mapletrader is here to shorten the learning curve! Goodluck!

[dirtnworm]

Thanks Mapleack,

I appreciate all the help I can get.