The plumber who makes the connection to the municipal water system shall install a main shut-off valve of the inverted key type on the water-service pipe near the curb with a suitable lock of a pattern approved by the Superintendent. The shut-off valve shall be covered with a heavy metal cover having the letter "W" marked thereon, visible and even with the pavement or ground.
The plumber also shall install a shut-off valve and waste cock on every service pipe inside the building near the entrance of the water-service pipe into the building; this must be located so that the water can be shut off conveniently and the pipes drained. Where one service pipe is installed to supply more than one customer, there shall be separate shut-off valves inside the building for each customer so that service to one customer can be shut off without interfering with service to the others.