fire sprinkler

Has anyone run into a multipurpose fire/domestic system?(Single family dwelling) Solo 1" service line in with a single fire meter upstream from the domestic branch line. The water within the fire suppression piping and domestic piping are co-mingled. Apparently this multipurpose system was...

Hello, I have this plumbing on the incoming water line coming into the home (See Pic). The pipe I have circled in black has sprung a very tiny leak . Does someone know what this type of pipe is called and why does the diameter get so constricted? I assume it may have to do with the fire...