Pressure drop in a compressed air system is the difference in air pressure from the compressor discharge to the actual point of use. Causes of pressure drop include mosisture separators, filters, dryers, fittings, valves, and resistance to flow within the air system piping. It is desireable to design a compressed air system to avoid excessive pressure drop which will cause an "artifical demand" and substantually higher energy cost. A properly designed system should have less than 10% loss of the compressors discharge pressure. (Also see the Van Air cost of pressure drop calculator.) This online tool is a guide for estimating the pressure drop contribution of the piping system. Simply choose the pipe diameter and the pipe schedule from the drop down menus. Enter the number of each piping component, the total straight length of pipe, plus the estimated pressure, flow rate, and temperature. Add the results to the combined pressure drop of your sytem purification equipment and other component pressure drops for a quick estimate of total system pressure drop.

Pipe Type		Equivalent Length (feet)	Number
Standard-ELL
Long Radius-ELL
T-Run
T-Branch
Globe Valve
Butterfly Valve
Swing Check Valve
Full Port Ball Valve
Straight Pipe
Equivalent Total Length			ft.

This calculation is based on the following assumptions:

1. All entries must be whole numbers.
2. Valves are typical for estimating only.
3. Friction data is for clean commercial steel pipe.
4. Flow is assumed to be in the turbulent zone.