Friction loss in piping refers to the amount of pressure that is lost as water moves through the piping. As the pipe diameter decreases or flow increases, the amount of friction loss or pressure drop increases as well. There are two ways to conserve pressure in piping systems. The first way is to decrease the flow rate of the system. If this is not a viable option, you can also increase the diameter of the pipe as a means of conserving pressure.
Below are charts for friction loss (pressure loss) for different types and diameters of pipe at various flow rates. The left side of the column shows various flow rate expressed in gallons per minute. Along the top of the chart are the different pipe sizes. Underneath each pipe size is the velocity of the fluid in motion expressed in feet per second (ft/sec) and pressure loss per 100' of pipe.
The shaded area of the chart shows where the velocity exceeds 5 feet per second. Avoid using pipe sizes and flow rates that fall within this area as this exceeds the maximum safe flow for piping systems.
If you already know the flow rate of your system, the type of pipe used, and the length, then you can enter that information into the Piping Friction Loss Calculator to automatically calculate the pressure loss.
|Class 160 PVC (SDR-26)
||Schedule 80 PVC|
|Sizes 1/2"-5"||Sizes 1/4"-3"|
|Sizes 2.5"-16"||Sizes 2.5"-16"|
|Class 200 PVC (SDR-21)
||Type K Copper|
| Sizes 3/4"-8"
|Schedule 40 PVC|
| Sizes 2.5"-16"
|Pipe Friction Loss Calculator
| Download Excel File
Pipe Dimension Guides
These guides are for common pipe types and sizes and are for reference only. All dimensions should be checked with the manufacturer and are subject to change.
SDR 21 - SDR 26 Specs
Sch 40 - Sch 80 Specs
Pipe OD Guide
Whether you have PVC, CPVC, or ABS piping, make sure you get the right cement and primer for the best joints. The links below will help you select the best cement for your application as well as give you vital information on cure times and applications.
Cement and Primer Selection Guide
Glue Set Times and Number of Joints per Quart
PVC Glue Types
CPVC Glue Types
ABS Glue Types and ALL Primer types
Aluminum Pipe Gasket Catalog Pages