Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Waste Water Piping - Flow Capacitiy vs. Dimension

In sewage piping and pumping systems the fluid flow rate must be kept within certain limits to avoid operating problems.

In sewage piping and pumping systems the flow velocity must exceed certain limits to maintain trouble free operation and to avoid settling and sedimentation of solids:

  • for horizontal wastewater pipe systems with solids the speed should exceed 3 ft/sec
  • for wastewater water system with organic solids the speed should exceed 2 ft/sec

On the other hand, the flow velocity should not exceed certain limits to avoid potential wear and tear due to erosion and abrasion:

  • the flow velocity in high-grit sewage handling systems should not exceed 12 ft/sec
  • the flow velocity in sewage systems with low grit concentrations should not exceed 18 ft/sec

Flow rate capacities in US gal for sewage piping and pumping systems within the limitations:

Waste Water Piping - Flow Capacities
Pipe Dimension
Flow Rate (US GPM)
Minimum VelocityMaximum Velocity
2 ft/sec
(0.6 m/s)
3 ft/sec
(0.9 m/s)
12 ft/sec
(3.6 m/s)
18 ft/sec
(5.4 m/s)
3 45 65 270 400
4 80 120 480 700
6 180 260 1050 1600
8 300 500 1900 2800
10 500 750 3000 4400
12 700 1100 4300 6400

Note! - based on clean pipes. The friction coefficient may vary with the pipe material.

Related Topics

  • Sanitary Drainage Systems

    The purpose of the sanitary drainage system is to remove effluent discharged from plumbing fixtures and other equipment.

Related Documents


Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .


This page can be cited as

  • The Engineering ToolBox (2003). Waste Water Piping - Flow Capacitiy vs. Dimension. [online] Available at: [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter