FIGURE A

SAMPLE SCHEMATIC DRAWING

**Be sure to add the pipe size for each run/length of piping

A sample schematic drawing of a gas piping system. It illustrates the layout from a gas meter through various sections (Section 1, 2, 3) to outlets (A, B, C, D) serving a furnace, automatic water heater, gas refrigerator, and range. Lengths in feet and millimeters are provided for each pipe run.
Method for determining correct pipe sizing per 1216.1.1:
  1. Compute CFM demand for all appliances
    • Maximum gas demand of outlet A:
      • 32 cubic feet per hour (from Table 1).
    • Maximum gas demand of outlet B:
      • 3 cubic feet per hour (from Table 1).
    • Maximum gas demand of outlet C:
      • 59 cubic feet per hour (from Table 1).
    • Maximum gas demand of outlet D:
      • 136 cubic feet per hour [150,000 Btu/hour divided by 1100 Btu per cubic foot].
  2. Determine the length of pipe from the gas meter to the most remote outlet (outlet A) is 60 feet.
  3. Using the length in feet column row marked 60 feet in Table 2:
    • Outlet A, supplying 32 cubic feet per hour, requires ½ inch pipe.
    • Section 1, supplying outlets A and B, or 35 cubic feet per hour requires ½ inch pipe.
    • Section 2, supplying outlets A, B, and C, or 94 cubic feet per hour requires 3/4 inch pipe.
    • Section 3, supplying outlets A, B, C, and D, or 230 cubic feet per hour, requires 1 inch pipe.
  4. Using the column marked 60 feet in Table 2 [no column for actual length of 55 feet]:
    • Outlet B, supplying 3 cubic feet per hour, requires ½ of an inch pipe.
    • Outlet C, supplying 59 cubic feet per hour, requires ½ of an inch pipe.
  5. Using the column marked 60 feet in Table 2:
    • Outlet D, supplying 136 cubic feet per hour, requires ¾ inch pipe.