Each hot-water riser throughout the building shall be accompanied by a corresponding circulation pipe, |-inch in diameter, which shall be connected to the hot-water riser by means of a return bend on the top floor of the building. The hot-water riser, also the circulation riser, shall be supported only at the second floor of the building, so the ends will be free to expand up and down.

Water-Heating Apparatus

The contractor shall provide and set up where shown on the plans, one steel hot-water tank 48 inches in diameter and 8 feet high, made of 5/16-inch steel plates double riveted, the seams calked perfectly water tight, and guaranteed to withstand a pressure of 300 pounds per square inch. The tank shall be connected by means of a 2 1/2-inch flow and return pipe to a cast-iron Ideal, Yale or Sunray water heater containing 6 square feet of grate surface and having a smoke flue of 10 inches diameter. The tank shall stand upright alongside the heater and both shall rest on a cement base especially provided for the purpose. Cover the hot-water tank with 1 1/4-inches of asbestos plaster smoothly troweled on over a band of expanded metal.