the reason we do not need expansion tanks on wet systems is due to water's low coefficient of thermal expansion, but since it is not zero, and assumed potable, we use a 1/2" relief valve. why on grids but not trees?, (until 13-2013)-- because with an aux drain on the secondary main, most of the air (cushion) can be purged at system charge or recharge. now with the emphasis on getting the air out, best to use a relief valve on trees too. this is my understanding-- i might be mistaken.
-----Original Message----- From: Ed Kramer [mailto:[email protected]] Sent: Tuesday, July 31, 2012 9:07 AM To: [email protected] Subject: RE: E x p a n s i o n T a n k s You don't. If that were the case, we'd have expansion tanks on wet systems also. Figure the tank size based on the volume of pipe exposed to temperature swings. But be conservative - some of the summer heat and winter cold will extend a short ways into the conditioned space. Ed Kramer Manhattan, KS > If anti freeze expands only when temperature extremes are encountered, > why size a tank for the whole system that sits in in conditioned or > heated air? _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum
