How to determine fluid velocity & hose ID

Flow velocity is determined by hose bore size and fluid rate. Our engineers have drawn a simple and easy-to-use nomograph to help you determine the media velocity. In most cases, fluid velocity should be among a safe range for different applications. Velocity varies depending on specified purpose. For example, fluid velocity is much higher than that of suction lines.

How to determine fluid velocity of hydraulic hose?

Oil velocities should be kept in the recommended range in the following chart. If it exceeds the range, turbulent flow occurs causing loss of pressure and excessive heat. Depending on the length of the hose and fluid transportation conditions, there are two options.

  • For long hose or the flow of the contents is continuous, it is recommended to use the velocity figure at the lower end of the maximum recommended velocity range.
  • For short hose or intermittent flow, velocity figure is usually rated at the higher end of the maximum recommended velocity range.

How to use this nomograph in the correct way?

  • First, determine the two known figures;
  • Second, draw a straight line to intersect the two values;
  • Third, the value on the third value line should be the figure you need.