The sizing, design and layout of the drainage system shall be permitted to be designed by approved computer design methods.
The load shall be computed from the simultaneous or sequential discharge conditions from fixtures, appurtenances and appliances or the peak usage design condition.
The discharge profiles for flow rates versus time from fixtures and appliances shall be in accordance with the manufacturer's specifications.
Pipe shall be sized to prevent full-bore flow.
Pipe size calculations shall be conducted with the pipe wall roughness factor (ks), in accordance with the manufacturer's specifications and as modified for aging roughness factors with deposits and corrosion.