rssahlman
New Member
I am fixing a system that had a valve failure and come across an issue that I need help with. The system has a master valve in the basement then a AVB outside on the down-flow side then the zone valves down-flow from there. I thought I would replace the AVB with a PVB. From reading I figure the PVB must be first before the master valve (so I will relocate that into box with zone valves) but the real issue I'm having is that the terrain will not allow the PVB to be above some of the sprinklers (house on a hill). What is my alternatives for back-flow prevention? I've been reading that dual check valves are not effective?