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A fixture unit is equal to one cubic foot of water drained in an 1 1/4 pipe over one minute ( 7.48 US gpm, 0.47 l/s). Fixture Units are used in plumbing design for both water supply (WFSU) and waste water (DFU).

A fixture unit is equal to one cubic foot of water drained in an 1 1/4 pipe over one minute ( 7.48 US gpm, 0.47 l/s). Fixture Units are used in plumbing design for both water supply (WFSU) and waste water (DFU).

The most common plumbing fixtures are bathtubs, sinks, showers, tubs, toilets and faucets. While a fixture can be fixed into walls or the floor, a fitting is an item that can be hung by a hook, screw or nail. Various types of pipe fitting are available in plumbing systems for different purposes and functions.

1 inch= 25.4mm, 1 ft. = 304.8mm, 1 gallon/m=3.785L/m. Water velocity should not be greater than 2.438m/s at valve seat to prevent noise and erosion. So, Pipe area should be at least equal to water flow rate divided by eight.

Add up the total number of water supply fixture units (wsfu) required in the facility. Estimate demand using the table from the IPC that correlates wsfu to expected demand. Size the pipe using demand vs.

A 3/8-inch line is sufficient for lengths up to 250 feet; 1/2-inch line will deliver adequate water pressure up to 350 feet; and 3/4-inch tubing is necessary to run a 500-foot line.

The most common pipe diameter for water mains is 6 to 16 inches, with 8, 10, and 12 inches also being used. Branch lines providing service to individual homes, offices, buildings, and businesses vary in size from as small as half an inch in diameter up to 6 inches.

200 fixture units are equivalent to a flow rate of 64 gpm (4 L/s) in a flush tank water closet system, or 90 gpm (5.7 L/s) in a flushometer valve system. 1,500 fixture units are equal to a demand of 270 gpm (17.04 L/s).

The more water that is being forced through a pipe, the more pressure there will naturally be. Through any pipe size, higher water pressure will cause greater water flow. The pressure will decrease downstream, however, because of loss of friction and water velocity increase.