You have probably walked by them and not noticed them but other times you may have with any where from 2 to 6 or more little individual hand valves on them depending on the size and volume pump puts out
They serve an important purpose they are used to test the Fire Pump which boosts the pressure to sprinkler system which protect buildings. Since water can not be run thru the sprinkler piping while testing the pump this bypass valve arrangement is installed and hoses attached to allow the water to flow towards a street drain. the valves can be individually open and closed to allow pressure against the pump while being tested . Got to see a test at a large storage facility once and was very impressive .
Check out this Youtube Video of a test being performed by a contractor
Yes unfortunately I run across Inspectors who are so attentive to absolute strict compliance of code they often end up causing code issues and often times because they are so attentive they miss major issues .
Take the case of a recent wedding venue I attended that just opened in an upscale community .
This particular inspector insists pull stations no more then 5 ft NFPA 72mandates how ever not taking into consideration the buildings design and ADA rules yes you guessed it every one of them are blocked .
As you can see in the picture the chair blocks the pull station . Had the inspector let the pull station be put on the side wall near corridor it would be free and clear and easy to operate but thats too far. But remember the inspector has the right to allow local judgement especially when it comes to something like this . Its called common sense and these inspectors do not have it and will not use it.
In the mean time while they where doing all of the inspections and their obsessions with tape measures to make sure everything is correct they totally missed the fact the raised platform where participants sit is of same material's main floor and has no safety edge to warn you are stepping down the result the night of wedding a 80 yr old women participant fell and severely bruised both knee's which more than likely is not going to end well.
Never fails I see this all the time over obsessed with compliance instead of using common sense to avoid issues it is just a matter of time this community is going to be hit with a major lawsuit because its inspectors have failed to protect the community by missing and or contributing to a major code violation where there is a loss of life. The clock is ticking .