Every service pipe shall be laid so as to allow at least one foot of extra length in order to prevent rupture by settlement. The service pipe must be placed no less than seven feet below the ground and in a manner as to prevent rupture by freezing. Service pipes must extend from the curb stop box to the inside of the building, or if not taken into the building, then to the hydrant or fixtures which it is intended to supply. All tubing and pipes shall conform to the Minnesota Plumbing Code. All underground joints are to be mechanical, except joints under floors shall be soldered in accordance with the Minnesota Plumbing Code, unless otherwise approved by the Utilities Superintendent. Joints of copper tubing shall be kept to a minimum, and all joints shall conform to the Minnesota Plumbing Code. All joints and connections shall be left uncovered until inspected by the Utilities Superintendent and must comply to the Minnesota Plumbing Code and tested at normal water line pressure. Unions must conform to the Minnesota Plumbing Code. Connections with the mains for domestic supply shall be at least one inch up to the curb stop box.