« on: January 06, 2010, 08:43:15 PM »
Most of the clear vinyl tubing I've seen at hardware stores is rated to 175F which should be fine for mash temps. In fact, I've been using this for a steam infusion line (250F) and it has held up for a couple of mashes, though it will need to be replaced soon with something better.
Not sure what tubing you're using, but it doesn't sound like it has a very good temp rating. Some of the stuff I see from Micromatic and elsewhere is rated to 212F and folks use it in their recirc systems.
I just read somewhere that if you start your run-off too quickly, it could create a vacuum and compact the grain bed. Sounds like using smaller diamater tubing is the opposite of that.