Follow The Lee Company
RESISTANCE TO FLOW IN TUBING
The Lohm Laws accurately relate flow, pressure drop, and Lohm rating for individual components. For tubing, however, these variables are best related in graph form. The following graphs show pressure drop and flow rate for four different standard sizes of tubing offered by The Lee Company. A 10 cm length of tubing is used in the graphs. If your flow problem involves longer tubing length, increase the pressure drop proportionately.
Example:
To find the pressure drop for a 30 cm length of The Lee Company’s standard 0.032” I.D. tubing flowing 100 mL/min of water, begin by consulting the water flow graph. The graph shows that the pressure drop is 4 psia for a 100 mL/min flow rate. Adjust this to your length of 30 cm by the ratio:
Due to slight variations that normally occur in the tubing I.D., these flow calculations for tubing are not exact but are useful for most design work.
Always verify flow calculations by experiment.
*There are many parameters to consider when determining V-Factor. Click here for more information.
