Values of C for the Williams-Hazen Formula

**Values of C for the Williams-Hazen Formula**
Type of pipe	Range	Average value	Design value
Cement = asbestos	160–140	150	150
Fiber	-	150	150
Bitumastic- or enamel-lined iron or steel, centrifugally applied	160–130	148	140
Cement-lined iron or steel, centrifugally applied	-	150	140
Copper, brass, or glass piping or tubing	150–120	140	150
Welded or seamless steel	150–120	140	140
Wrought iron	150–80	130	100
Cast iron	150–80	130	100

SOURCE: Cameron Hydraulic Data, 15th ed., Ingersoll Rand Company, Woodcliff, N.J., 1977; used with permission.