<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by HooKooDooKu</i>
<br />Can't help you on the codes for NJ.
This is because in a critical failure, the device provides no protection, where as with an RPZ, a critcal failure usually results in lots of water comming out of the device and not back-flowing into your potable water supply.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Need help understanding, critical failure in the backflow device or in the sprinkler system? Next thing I need help with is, how does water get sucked backwards thru a control valve? If a control valve fails open - you see water passing thru to the sprinkler head. Do control valves fail in the closed position just enough so that when you use water in the house it creates enough vacuum to suck dirty water in from your sprinkler system? Wouldn't I notice air in my house water lines if that happened? I'm for backflow prevention, I just want to know more, yes I have read the tutorial from Jess. I do think of one example, if the water company had a break and had your water off, no backflow prevention on system, your controller opens valves to water, no pressure. Then would it run back into the house and the water main?