Hazen & Williams - Friction Factor C
Type of Pipe	Values of C
	Range High = Best Low = Poor	Average Value for Clean, New Pipe	Commonly Used Value for Design Purposes
Cement- Asbestos	160-140	150	140
Fibre	-	150	140
Bitumastic-enamel-lined ironed or steel centrifugally applied	160-130	148	140
Cement-lined iron or steel centrifugally applied	-	150	140
Copper, brass, lead, tin or glass pipe and tubing	150-120	140	130
Wood-stave	145-110	120	110
Welded and seamless steel	150-80	130	100
Interior riveted steel	-	139	100
Wrought-iron, cast-iron	150-80	130	100
Tar-coated cast-iron	145-50	130	100
Girth-riveted steel	-	130	100
Concrete	152-85	120	100
Full-riveted steel	-	115	100
Vitrified, spiral-riveted steel (flow with lap)	-	110	100
Spiral-riveted steel (flow against lap)	-	100	90
Corrugated steel	-	60	60

Values of C	150	140	130	120	110	100	90	80	70	60
*Multiplier (Basis C = 100)	.47	.54	.62	.71	.84	1.0	1.22	1.50	1.93	2.57

Increase in Friction Loss Due to Aging of Pipe

The deterioration of pipes over time is a function of the chemical properties of the the materials from which it is made, the liquid flowing within it, and the material that the pipe itself is held in. In general, the friction loss increases with age as patches of corrosion and buildup form.

These values are largely theoretical and should be used for estimation purposes only. The wide variety of water conditions around the world makes any precise calculation of values impossible. This table is based on the best-known available data, but should still be used with discretion.

Multipliers for Use with Friction Loss Tables