How do I know what size hydraulic hose I need?

When it comes to hydraulic hose sizing, selecting the right size hydraulic hose is essential for the safe and efficient operation of hydraulic systems. An incorrect size can lead to reduced performance, system failures, and even safety hazards. In this guide, we’ll explore the key factors to consider when determining the correct size hydraulic hose for your needs.

Hydraulic Hose Replacement

Understanding Hydraulic Hose Sizing

Hydraulic hoses are measured by their internal diameter, external diameter, and length. These measurements ensure the hose fits the system components properly and can handle the required flow rate and pressure. The wrong size can cause issues such as restricted flow, increased pressure drops, and overheating.

Key Factors to Consider

  1. Flow Rate The flow rate of the hydraulic fluid is a critical consideration when choosing hose size. The internal diameter (ID) of the hose affects the fluid velocity and flow efficiency. A hose that’s too small for the required flow rate can cause turbulence, leading to energy losses and increased heat generation.
  2. Pressure Ratings Hydraulic systems operate under high pressure, so the hose must be able to handle the working pressure of your system. Always check the pressure rating of the hose and ensure it matches or exceeds the system’s maximum operating pressure. Using a hose with an inadequate pressure rating can lead to dangerous bursts or leaks.
  3. Length of Hose The hose length impacts pressure drop in the system. Longer hoses tend to experience greater pressure loss, which can reduce system efficiency. Additionally, ensure the hose is long enough to accommodate movement and flexibility without being stretched or stressed.
  4. End Fittings The size and type of end fittings must match the hose and the equipment. Improperly sized fittings can lead to leaks, inefficiencies, and potential equipment damage. Always use fittings that meet industry standards and are compatible with the hose and system.
  5. Standards and Manufacturer Guidelines Hydraulic hoses are designed to meet specific standards, such as ISO, SAE, or EN specifications. These standards provide guidance on dimensions, performance, and safety. Refer to the manufacturer’s documentation to ensure the hose meets the requirements of your application.

Measuring Hydraulic Hose Size

To determine the correct size, follow these steps:

  • Measure the Internal Diameter (ID): Use a calliper or refer to the hose’s specifications to measure the internal diameter. This measurement ensures the hose can accommodate the required flow rate.
  • Calculate the Length: Measure the distance between the system’s connection points and add extra length for flexibility and movement.
  • Check External Diameter (OD): For routing purposes, ensure the external diameter fits within the available space and doesn’t interfere with other components.

Using Dash Numbers

Hydraulic hoses are often sized using “dash numbers,” which correspond to the hose’s internal diameter in 1/16-inch increments. For example, a “-08” hose has an internal diameter of 8/16 inches (or 1/2 inch). Ensure you convert these measurements if needed to match UK metric units.

Get Expert Advice

With 86 centres located around the UK and Ireland one of our UK Hose experts will be able to help you with your hydraulic hose needs, stocking all the components you will need.