3/16 tubing contraction in cold weather?

[katmike]

Just put up some CDL semi-rigid 3/16 tubing for next season and my first attempt at any type of tubing (gravity).

As I was putting it up I was amazed at how the barbed connectors keep it from slipping off even as tight as I was pulling it. Still seeing some sag in a longer run between a couple trees. Since it was about 80 when I put it out, can I expect much contraction in the colder months?

[WESTVIRGINIAMAPLER]

It won't pull apart if you are concerned about that. When he had crazy February weather last year and many times temps and wind chills way below zero, not a single issue even with it frozen completely full of sap. The fittings hold well. Little sag now won't be an issue in syrup season but if it is 80 outside, no need to stretch it crazy tight.

[Daveg]

According to "The Engineering Toolbox", the contraction should be about 1%.
"Tight, straight, downhill" is the tubing mantra. Sags are ok AS LONG AS THE SAG IS ALSO SLOPING DOWNHILL.