In a nutshell, yes a back flow preventer is basically a check valve. However if it is on your fresh water line from the meter there is a little more to it than that. here in Cali it will cost a grand and up for a proper BF device between permits, purchase price, installation, inspection, testing and certification. I don't know about Ohio, but out here you better put a cage anchored in cement around the BF or it will get stolen sooner or later. Metal thieves will get a few bucks for the brass, leaving you to pay hundreds or thousands to replace it.
Dedicated Stick Burner, Pitmaster @ All About The Q, facebook.com/itsallabouttheq KCBS CBJ