Selecting the right line size for a hydraulic system is essential to ensure maximum performance and longevity of your hydraulic components. There are four main types of pipes in a hydraulic system: the suction pump, the return pump (low pressure), the hydraulic hose, and the hose arrangement. The hoses should have their part number, nominal pressure, and size stamped along the outer cover. Hose manufacturers usually provide a nomograph or table that allows you to easily calculate the optimal diameter for a given flow and hose length.
Most hydraulic hoses are composed of layers of braided wire and include steel fittings at the end of the hose assembly. The SAE J517 standard for the common series of hydraulic hoses 100R also classifies leaks and also the separation of hoses from hose fittings, such as breakage pressure faults. When it comes to selecting the right pressure rating for tubing in a hydraulic system, it's important to understand that static pressure classification is equal to dynamic pressure rating multiplied by 1.33. This means that if you have a dynamic pressure rating of 10,000 psi, then your static pressure classification should be 13,300 psi. For information on higher nominal pressures, contact Parker Hannifin Tube Fittings Division or Motion. When designing a new hydraulic machine or reconstructing an existing one, it's important to choose a hose with a maximum working pressure (WP) equal to or greater than the normal maximum pressure of the hydraulic system.
The inner diameter and nominal working pressure of a hose are typical factors to consider, but the outer diameter and weight of a particular hose model are often critical in mobile machines. Supporting hoses is also important in order to avoid tension on the fittings, eliminate the risk of tripping, and prevent them from shaking when pressurized and contracted. Bending and twisting can also cause serious strain on most hydraulic hoses, so it's important to take this into consideration when selecting your line size. By using this information and selecting the right line sizes for your hydraulic equipment, you'll enjoy better performance and a longer lifespan of your hydraulic components. With this technical tip, you can make an informed decision when choosing your line size.