Working with Liquids

Every engineer will be interested in our simple method of defining the resistance to fluid flow for hydraulic components. Just as the Ohm is used in electrical engineering, we find that we can use a liquid Ohm or “Lohm” to good advantage on all hydraulic computations.

When using the Lohm, you can forget about coefficients of discharge and dimensional tolerances on drilled holes. These factors are automatically compensated for in the Lohm calculations and confirmed by our testing of each component to establish flow tolerances. The resistance to flow of any fluid component can be expressed in Lohms.

The Lohm has been selected so that a 1 Lohm restriction will permit a flow of 100 gallons per minute of water with a pressure drop of 25 psi at a temperature of 80°F.

Due to the differences in fluid properties between gases and liquids, the equations for calculating the relationship between flow restriction, pressure differential, and flow rate are different.

View the resources below to learn all about Lohm Laws in applications for liquid flow:

• How to Calculate Flow Resistance for Liquids
  Define and measure resistance to hydraulic flow to ensure the proper flow rate
• Two Formulas for Combinations of Restrictors
  Learn how liquid Lohm equations apply to restrictions in series and in parallel
• Viscosity Compensation Factor “V” for a Single Orifice
  Discover how changes in pressure will impact the viscosity of a liquid
• Viscosity of Typical Fluids vs Temperature
  Determine how temperature will affect the viscosity of typical fluids
• Specific Gravity of Typical Fluids vs. Temperature
  Learn how the specific gravity of common fluids changes with temperature
• Lohm Calculator
  Use the online tool to have Lohm rate, flow rate, or pressure differential easily calculated for you