The diagrams below can be used for design of sewage and wastewater gravity conveying systems.
Sewage Pipe Capacity - Imperial units - gpm
Sewage Pipe Capacity - SI Units - liter per second
Example - Capacity of a Sewer Pipe
The capacity of a 4 inch sewer pipe with decline 0.5% is aprox. 25 gpm (1.6 liter/s).
- 1 gal (US)/min = 6.30888x10-5 m3/s = 0.227 m3/h = 0.06309 dm3(liter)/s = 2.228x10-3 ft3/s = 0.1337 ft3/min = 0.8327 Imperial gal (UK)/min
Decline and Slope
Calculate between decline and slope units
d = 8.33 s(in/ft)
= 100 s(ft/ft)
= 100 s(m/m)
= s(ft/100ft) (1)
d = decline (%)
s = slope
Example - % Decline
1/8 in/ft slope can be transformed to % decline as
d = 8.33 (1/8 in/ft)
= 1.04 %
Pipe lines - fluid flow and pressure loss - water, sewer, steel pipes, pvc pipes, copper tubes and more.
The purpose of the sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment.
Dimensions of copper tubes ASTM B306 Drain Waste and Vent - DWV.
Calculate the discharge length from the open end of a partially filled horizontal pipe.
Dimensions of cast iron soil pipes.
Cleanouts provides access to the sewer for rodding.
DFU are used to calculate the drainage flow from fixtures and the required capacities of sewer service systems.
Weight or density of ditch filling materials.
Drain pipes and vent stack sizing.
Support of Drain Waste and Vent - DWV - pipes.
Drainage Fixture Units (DFU) connected to building drains and sewers.
Commonly used standards for fiberglass pipes and their applications.
Recommended drain trap sizes for different types of fixtures
Calculate cross-sectional average velocity flow in open channels.
Relative capacity between larger and smaller pipes.
Calculate expected volume flow load in sanitary drainage systems.
Maximum Drainage Fixture Unit - DFU - loads in sanitary piping systems.
Septic systems handles waste from drain systems.
Viscosity of sewage sludge vs. content of solids.
Roof drain capacities.
Storm-water runoff coefficients for various surfaces
No. of fixture units and required trap size.
In sewage piping and pumping systems the fluid flow rate must be kept within certain limits to avoid operating problems.