Stubbies and Extensions

[maplwrks]

For the sake of discussion--What do you folks like to use for stubbies(straight or ninety degree) extensions (5/16 or 7/16) adapters(do you wash or throw away?)
I like straight stubbies and throw away my adapters each year. I have 30" drops and put a long "sweep" in the drop to go straight into the tree. (check my photo album) The theory for straight stubbies is this--the vacuum does not need to make a ninety degree turn to get to the spout. Liquid and vacuum flow is interrupted by the sharp change in direction. Does it make a difference?? Hell, I don't know, but it sure sounded logical to me!! What do you guys think???

[Thompson's Tree Farm]

Just started switching to stubbies and I got the 90 degree ones. Hadn't given much thought to turbulence and flow right at the tap hole. I discard extensions. I believe the research that shows you really can't effectively clean them.

[Brian Ryther]

There can't be that many cfm's at the tap hole to make tirbulance. Unless you have a leak. I was using the 90 taps with extensions last year. They produced 22 gal of sap per tap last year. I was very happy with that result. This year I am switching over to stubbies and check valves. If I do not do better than 22 gpt then ..... I will be full of excuses.

[KenWP]

There is a formula someplace that tells you what a 90 degree fitting is equal in length of pipe. So all those 90s would actually add up after a while plus the 90s in the mainline and from the vacuum pump. So the straight fittings do have value when it comes to putting them against 90s. Ask any gas fitter about this.

[DrTimPerkins]

The theory for straight stubbies is this--the vacuum does not need to make a ninety degree turn to get to the spout. Liquid and vacuum flow is interrupted by the sharp change in direction. Does it make a difference?

The hydraulic resistance (for vacuum or sap) due to a single 90 degree bend is real (so the salesman was telling the truth), but it is extraordinarily small at the flow rates encountered from the tree. Thus the functional difference is essentially negligible. It comes down more to a matter of preference.

The primary benefit of the stubby/adapter combination is that the adapters can be replaced EVERY year (glad to hear that's what you're doing), and you can thus maintain a cleaner interface between the taphole and the tubing system. If you're not doing it this way, then you aren't getting the benefit of using this system. By using a new adapter (or a new spout) each year, you can expect to see about a 10-15% increase in sap yield (if you tubing is more than a few years old).

[Russell Lampron]

I have been using the stubbies with good results. 19.2 gals of sap per tap from red maples. This season I am going to install some of the straight taps to see how I like them. I too use the adapters and discard them. I am also going to use 100 CV adapters this season on the tubing that was new last year.

[Amber Gold]

I use the 90 degree stubbies and spout reducers. I'm switching to the straight stubbies for stuff I'm adding this year. I think it'll make putting taps in easier and getting a better flow path, especially on the smaller trees.

Going to run a little experiment this year. If I can get them I'm going to run 2-300 of the CV spouts. I'm going to have a short mainline w/ 25 taps on it w/ used, sterilized spouts, another mainline w/ new standard reducers, and the rest on the CV spouts. See which stops when.

[DrTimPerkins]

Going to run a little experiment this year. If I can get them I'm going to run 2-300 of the CV spouts. I'm going to have a short mainline w/ 25 taps on it w/ used, sterilized spouts, another mainline w/ new standard reducers, and the rest on the CV spouts. See which stops when.

If ALL the lateral line is new tubing, I wouldn't expect that you would see much of any difference. The CV spout was designed to prevent contaminated sap from tubing from getting back into the taphole. If the tubing is new, it has very little microbes in it for the first season, so the benefit from the CV spout will be far lower than normal (although there would still be some small sap gain from the reduction in reabsorbtion during refreeze) . The older the tubing the greater the potential benefit.

[Amber Gold]

All but the taps I add this year will be on 1 year old tubing. Most of the new stuff will be on the CV mainline so the CV spouts will be on a combination of old and used tubing...mostly used. I want to keep the different spouts on different mainlines so if I find out one spout stops sooner I can just turn a valve and shut the mainline down while the others still run.

[caseyssugarshack93]

Dr tim, lets say im on Vac but with a Gas pump would the Cv adaptor be benifical with a new tubing on gas pump= When the Gas runs out? i plan on adding like 300 on BRAND NEW TUBING but with a gas pump and probably A other 200-300 on new tubing but connected to a season old system,?

[DrTimPerkins]

Dr tim, lets say im on Vac but with a Gas pump would the Cv adaptor be benifical with a new tubing on gas pump= When the Gas runs out? i plan on adding like 300 on BRAND NEW TUBING but with a gas pump and probably A other 200-300 on new tubing but connected to a season old system,?

On brand new tubing there will be only marginal benefit beyond that of using a regular annually replaceable spout adapter. The benefit increases as you increase the age of the tubing system.

The amount of backflow you get depends upon many things....your pump, your releaser, your management of the vacuum system, leaks, etc. In general, if you shut your pump off during the season, CV spouts will help. If you have a mechanical releaser, CV spouts will help. When you get leaks, the CV spouts will help. Every time the trees refreeze, the CV spout will help. How much they help at each of those times depends upon a lot of things, but one of the bigger influences is the age (and thus the level of contamination) of your tubing system.

[caseyssugarshack93]

the vac pump will be shut off and i have mechainal releasers and i get leaks but fix then, I walk the lines pretty much everyday, so Im guessing i still will see it being benifisa sincei have gas pump= shutting off and mechaical releasers,

[sapmaple]

I am putting up some brand new tubing this year and want to have the option to use the CV spouts in the future so any thoughts on which stubby would work best with the CV spout
I know all the brands will fit except CDL's

Seen some fit better on the CV then others the leader stubby does not slide in all the way others do, ie D&G some seem tighter on the inside area
Any input would be helpful
Hope I'm not to far off topic that Mike started
Thanks Kevin