All copper is Type "L" and meets all UPC as well as national plumbing codes. One ball valve per washer inlet on all our bulkheads. All water lines are installed with adjustable clamps attached to unistrut, for ease of adjustment in the field. All copper fittings are pro press fittings clamped to the pipe and sealed with an "O" ring. All fittings are warranted for 50 years.