|Criteria for Selection of the proper components for a fluid flow system:
At a given flow, the pressure drop of the components in a pipe system will add up to a sum equal to the line pressure if the components are properly sized.
The tables are designed to offer a quick reference of pressure drop values for a valve and a given length of pipe. Adding the values together will yield an estimated total pressure drop. The tables are not meant for designing pipe systems. The first column shows the Flow Rate, you can assume readings half-way between the readings shown to have a pressure drop approximately half-way between the pressure drop readings shown.
WATER & OIL* FLOW TABLES:
Due to waters low compressibility, the flow and pressure drop can be shown with a uniform length of pipe of 100 feet. The pressure drops for other lengths of pipe are simple fractions or multiples thereof.
* For light oil up to #3, use the same readings as water. For medium heavy oil add 70% to the pressure readings shown.
GAS FLOW TABLES:
Natural (heating) gas also has low compressibility, however the flow and pressure drop is shown for two different lengths of pipe as the pressure drop at higher pressures are not proportional.
DOWNLOAD FLOW TABLES (PDF)
Flow Table - Air - Table A
Flow Table - Air - Table B
AIR & STEAM FLOW TABLES:
For compressed air or steam, the ratio between quantity and volume changes continuously as the air or steam flows through the pipes and accessories (valves).
Two tables are presented:
Each table shows the pressure drop for two lengths of pipe, enabling the user to estimate the drop for a shorter or greater length of pipe.