Sizing wet line for remote section

I have an upper section of woods that I'm reworking my conductor lines this year to increase vac to the far end and remove the lower section that has manifolds directly into the wet line. The old wet line will just be its own mainline direct to the releaser. The section starts about 1000 feet from my releaser and then the farthest mainline branches off another 1500 feet from that point. All my mainlines branching off this section are 1" pipe. It will have approximately 2000 taps on it. I purchased 1000 feet of 1.5 inch line for the dryline to the first juction and then it will drop down to 1.25 inch for the dry the rest of the way. I wanted to know what everyone thought was the right size wet line to use for the 1000 feet coming from the first junction to the releaser. My instinct is to use 1.25 line but after reading a bunch of posts it seems like you want to try to get the smallest diameter you can to keep sap temps lower. Would 1" be a better choice for my wet line? It runs about a 5-6% slope through that area.

The other necessary information is how many CFM's is you vacuum pump and what is the total taps on the line, old and new?

Joe

Ok, I'll give more detail. The plan is to have 2000 taps on this section by the year after next. I think I have the math figured out for CFMs. I have an 80cfm pump running 2 releasers. The first one is capturing only 800 taps and there really isn't much growth available. This section's releaser will have around another 1000 taps feeding off other ports. So a total of 3800 taps total for that pump and around 3000 taps to the releaser with the section I am talking about. This releaser is approximately 600 feet from the pump and I am switching from a 1.25 inch line feeding vac to it to a single 2" line. That should increase my CFM to around 48 at the releaser from around 15. This year I had only 1400 taps on this releaser and was running into trouble having enough vac at the end taps Started the season at 14HG at the top of the bush and finished the season around 23" after many leak checks and fixes. Smaller releaser started at 19" and ended the season at 27"
Based on upgrading to a 1.5" dry line even if my wet line is completely full my dry line should still have 21 CFM at the start of my 2000 tap section and more if the wet line has air capacity. The big question is go with a 1.5 dry 1.25 wet and have approx 31CFM capacity at my 2000 tap section or go with a 1.5 dry and 1" wet and have 29CFM at that section. Normal planning is to have 100 taps per CFM so both are enough vac capacity but should I go with the smaller wet line to keep the sap cooler? My first instinct was to go with 1.25 but it is a very open section with no trees blocking the afternoon sun so reading about using minimum wet line sizing started making sense. Hopefully that is enough detail to get some opinions. :)

My first suggestion is to go with 1 1/2 " wet line. I an pretty sure that 1" is way too small for 3,000 taps. Too small of a wet line will block any air movement in the wet line and reduce the vacuum available.
The following comments do not take into account the amount of CFM's used by the other releaser
It does not matter how big your vacuum pump is, at 600' with 1 1/2" dry line, a 60, 80, or a 100 CFM pump will deliver the same amount of CFM's.
If you install 11/2 dry line 600' from the pump, that line will have 21 cfm's available and capacity for 1,700 taps. At the end of the dry line, there will not be very many CFM's left.
If you want to maximize your vacuum level to as close to 27" or 28" as possible, I would suggest using 3" pipe for at least the first 600' to the releaser. This would give you 72 CFM', (less the CFM's used by the other releaser). Then continue the dry line with 2" to the end of the mainlines. This should give you enough CFM's for the 3,000 taps.

As you know, the longer the length of the dry line, the more friction loss and reduced CFM's. Start big and get the proper capacity of vacuum to the taps where it counts.

Joe

I suggest you get a copy of Steve Childs' Maple Tubing Notebook. it will give you the info you need.

I have 2000 on 1 1/4” over 1 1/4” that runs 2500 then branches off. Run 27+ all season and average .40 gals every year. Maybe should go 1 1/2” on dry line but just too lazy. Also have no problems with temp in lines, usually a lot of med/light syrup. Just for your info...

Thanks! I'll just stick with my original plan of 1 1/4 wet with the 1 1/2 Dry. My 2 inch feed to the releaser should put enough CFMs for the section and i won't worry about the sap temp.