Velocity =

Roughness Coefficient =

Hydraulic Diameter =

Slope =

Calculates the Hazen-Williams equation on pipe fraction. [http://en.wikipedia.org/wiki/Hazen–Williams_equation|Per Wikipedia]:

"The Hazen–Williams equation is an empirical formula which relates the flow of water in a pipe with the physical properties of the pipe and the pressure drop caused by friction. It is used in the design of water pipe systems[1] such as fire sprinkler systems,[2] water supply networks, and irrigation systems."

This version assumes US customary units.

- V: velocity

- C: roughness coefficient

- d: hydraulic diameter

- s: slope of the energy line

Roughness coefficient (low-high):

Asbestos-cement: 140

Cast iron new: 130

Cast iron 10 years: 107-113

Cast iron 20 years: 89-100

Cast iron 30 years: 75-90

Cast iron 40 years: 64-83

Cement-Mortar Lined Ductile Iron Pipe: 140

Concrete: 100-140

Copper: 130-140

Steel: 90-110

Galvanized iron: 120

Polyethylene: 140

Polyvinyl chloride (PVC): 150

Fibre-reinforced plastic (FRP): 150

Contributed by Anthonie Schuur

Velocity

Roughness Coefficient

Hydraulic Diameter

Slope

-------------