1. Anybody know a good chinese supplier of pvc fittings? Recently paid $20 for a 2 inch pvc union at southern drip irrigation. 2. My system is half pvc and half poly. I will switch to all poly as temp gets down to minus 12 in winter. I will continue to use pvc valves and unions because it is impossible to disconnect poly compression couplings in cold weather. 3. The majority of the system is not buried so I have to allow water to drain during the winter so that there is constant flow. A dripping tap is not enough. During summer the drain is shut off. Some of the line is a few inches from ground so I will bury that. I think that will add some energy to the system during winter. 4. A flat area of pipe near the end of the line seems to freeze first when I forget to open drain. The steeper area closer to intake takes at least a couple days to freeze. 5. I was going to ask about how to make a gradual 90 degree turn with pvc pipe but I guess I will just use a piece of poly. Once i convert to all poly this will be moot. Currently using two 45 degree elbows. 6. Why pvc doesnt work. a. gets fragile when cold and breaks when undoing union. b. ice expansion breaks it easily c. ice builds up on outside of pipe and weighs it down and breaks it d. plastic weld joints fail sometimes I guess this is more a tutorial. Hopefully, someone will not make the mistakes i made.