3/16 Vacuum Problem

[Crowsap]

I have five 3/16 lateral's connecting to one 3/4" main line and they were all running really well today,(At least where they connect to the mainline). When I went to check my vac gauge's at the start (top) of each lateral they all read 0 vac? I have been told I have a blockage in a "T" fitting downhill from the gauge's. I did not walk the lines yet.The vac gauges are installed correctly. Would there be any other reason for this? This is my first year so very little experience.

Thanks

[Haynes Forest Products]

Don't count the 3/4 line when it comes to the vacuum. What I mean is if your going 15 ft to the 3/4 and then down hill 30-50-60 ft to you tank you only getting the 3/16 worth of vacuum.

[Crowsap]

Yup understood. My 3/16 lines are 500 plus ft long and tie into the mainline way down low closer to collection tank. I have 200 feet of drop from top to bottom with almost all of the trees 30 plus ft above the tank. Pretty steep grade.
Thanks for the reply.

[wnybassman]

If they are running good, on that slope, you have vac. Seems odd all five all doing the same thing, that's too coincidental. Is there sap moving in the lines right near the gauges?

[Crowsap]

I only had time to check 4 of the 5 gauges. The first 3 had no sap running at the gauge the 4th one was flowing really well but the gauge was at 0. I was on lunch break so didn't have time to check 5th gauge or walk the lines. All of them were flowing very well down low into the mainline. I guess I'll have to walk them from bottom to top to find where the potential restrictions are.

[mol1jb]

Busted gauges maybe? I hear those 8 dollar vac guages arent super durable, especially if left in the elements.

[Crowsap]

They are all new and I tested them before installing. Not cheap ones either.

[Alex Davies]

Take needle nose vice grips, grip/pinch the dropline at your uppermost tree. Pull the tap, put your tongue on the end of the tap, and release the vice grips... You'll know if there's vac.

[Crowsap]

Thanks I will give this a try.

[steve J]

I am on my 5th or 6 th year with 3/16 and I have yet to get a gauge to register but you can see the sap racing thru the line so you know its truly working. I am just tapping now and this year I added stubbies and clear check valves and what I have noticed is less air bubbles in my lines so it appears to be moving even more sap.

[Biz]

Do you see sap in the lines going to the gauges? I had a problem last year with gauges on 3/16 lines, about half of them failed, possibly due to sap backflow into the gauge and freezing.

[maple flats]

Never put your tongue on any tap, that's a sure fire way to contaminate that tap and kick start the tree to close off that tap, the bacteria in every ones mouth will contaminate the tap. You could however try a clean baggy or similar.
For vacuum gauges, there is no reason to buy pricey ones for the inline gauges. A $3-4 gauge will be just as reliable. Spend your $ on things that will help you make more syrup. I bought mine for $3.25 off ebay last year. I just did a quick search and see some for $3.40. The failure rate will be very similar to ones costing 3-4X that: https://www.directmaterial.com/1-1-2-utility-pressure-gauge-wog-black-steel-1-8-npt-lower-mount.html?gclid=CjwKCAiA8bnUBRA-EiwAc0hZk657iekjniX-uXGdZgY72lsILdxqAEhscsMJG2T0GcFohmDh_ntueRoCM7gQAv D_BwE

[Crowsap]

I guess if it is flowing good I am not going to worry about it. The lines to the gauges are empty. Good call on using a bag vs tongue. Thanks for all the replies.

[wnybassman]

Key words I am seeing here from a couple of you with gauges not reading anything. Sap "racing by" and "sap moving really well". You don't have the lines vented at the tops of the laterals, do you? They can not be vented.

[Crowsap]

No my lines are not vented.

[wnybassman]

Hmmmm.

I would definitely pull a tap and check with a bag. Just pulling it during good flow there will be a huge sucking sound.

I have checked gauges by attaching a couple foot long or so chunk of tubing and sucking on it.

[BAP]

Sap should not be racing through the lines if you have a tight line. It should flow at a steady pace but not fast. If it is fast you have a leak.

[Crowsap]

Ok thanks for all the feedback. I will be checking for leaks tomorrow.

[johnpma]

Where are you guys installing your gauge? above the last tap?

[BSD]

Where are you guys installing your gauge? above the last tap?top of the line, make sure it's above the tap-hole. i like using the 2 way end of line hooks for them.

[wnybassman]

Mine are all near the top of the runs, most above all taps on line, but some are not. Gotta figure it out, because this is very fun to see!!!

17760

[Crowsap]

Agreed. I wish my gauges looked like that!

[maple flats]

While I by no means have gauges on all lines, on my 3/16 I have them on maybe 20% , at the top tree, entering via a T just like another drop, with the gauge slightly higher than the tap(s) on that tree. Then on 3 or 4 such lines I also have another gauge just under half way down, or more accurately at 12-15' of elevation above the main it is connected to, just to give me an idea. My lines however are hybrid, I have 19" vacuum on the mains and then the 3/16 generates more. The ones at the top tree, all of which are over 30 higher than that main, show 28-29" vacuum depending on the weather. the lower ones are usually within an inch of the top ones. That would not be the case if I didn't have the pump on the mains.

[Crowsap]

I checked all my taps/lines today. I had to tap in the spouts and check valves on most of them as it seemed they were leaking and not fully seated (My bad). Sap was running but I still had 0 vac on gauges. I will check them again once it starts to run better to see if this was the issue. Thanks again for all the replies.

[Crowsap]

I was able to walk my lines again today while the sap was running. I could not find any leaks or plugged t's and my vac gauges still read 0. The sap was running well on all 5 laterals. I installed my gauges with a "T" into the 3/6 lateral at the start (Highest Tree) and ran 3/16 tubing into 5/16 tubing to the gauges and tied to the tree several feet up above. There was a little sap in all the 3/16 tubing but not high enough to reach the 5/16 tubing. I disconnected one of them and pulled vac on the 5/16 line to the gauge and the needle moved as expected. Not sure at this point why they are not reading any vac but the sap is flowing steady so i am not going to stress over it but it does bother me that I can't figure it out!

[BSD]

If the need moves when you apply vacuum (i assume you're sucking on the line) then there is a leak somewhere. it takes my natural vac system at least 20 minutes to regain vacuum if i vent the system to change a T or drop.
Was the whole line moving? i spent the better part of the day chasing plugs in T's today as fall-out from our 74 degree weather we had last week. some lines were running great, but only part way up the hill. above a plugged T it would be full of sap, or even empty since there was no vacuum pulling on the taps. as i cleaned out the plugs i had one line which wasn't running at all finally wake up and go from 0 to 27" of vac in about 2 hours.

[Crowsap]

Ok this makes sense, I walked from the collection tank to the top of each line. On the lower trees there was air between the sap in the line and as I got higher in elevation the lines were full with no air in between. I grabbed the lines in each case where they seemed full and bent it to a 90 degree upward shape and it created air separation so I could actually see the sap flowing. It was flowing in this manner on all of my lines as I got higher i had to use this method to see if it was full or empty of sap. It was full in every instance. I noticed at one of my T's it was solid liquid uphill and then as it exited the T it was creating the air separation I could see down below. This T must have the obstruction? I could not pinpoint this on every line but this must be my problem?

[BSD]

Ok this makes sense, I walked from the collection tank to the top of each line. On the lower trees there was air between the sap in the line and as I got higher in elevation the lines were full with no air in between. I grabbed the lines in each case where they seemed full and bent it to a 90 degree upward shape and it created air separation so I could actually see the sap flowing. It was flowing in this manner on all of my lines as I got higher i had to use this method to see if it was full or empty of sap. It was full in every instance. I noticed at one of my T's it was solid liquid uphill and then as it exited the T it was creating the air separation I could see down below. This T must have the obstruction? I could not pinpoint this on every line but this must be my problem?I would start at the T where the bubbles start (from the drop). pinch the line off above with needle nose vise grips about 6" above the fitting so you don't take a sap-bath. put a piece of tubing over the pliers so you don't put any hard creases in the 3/16. replace the T. i bet it's plugged or manufacturer defect.

[Crowsap]

Ok thanks a lot I appreciate it.