Re: Sprinklers - Pressure relief

["pulic emeny" <spam@xxxxxxx>]

"Bob La Londe" <nospam@xxxxxxxxx> wrote in message
news:45c13071$0$1876$88260bb3@xxxxxxxxxxxxxxxxxxxx
>
> "nick markowitz" <nick-markowitz@xxxxxxxxxxx> wrote in message
> news:Q_awh.8445$SE6.7503@xxxxxxxxxxx
>> All new sprinkler systems have a backflow prevention valve older systems
>> had check valve
>
> Ok, but how is the pressure relieved in a sprinkler system from the
> expansion and contraction of the water trapped in the system?

don't know about  sprinklers but my hot water heater has an air tank.:)