When it comes to hydraulic systems, the inner diameter (ID) of the hose is the hole through which the fluid must travel along a given length. The outer diameter (OD) of the hose is also important, as it affects factors such as where the hose will fit and how strong it is. A thicker, high-pressure hose will have a greater thickness relative to its internal diameter. The length of the hose will determine what types of flows you can handle, taking into account its inner diameter.
To make this easier, you can use the Gates nomographic chart found in the Gates Hydraulic and Fleet Hose catalog. This chart helps you determine the right size of the hose depending on the flow and velocity of the fluid. When it comes to hydraulic hose assemblies, several measures must be considered to ensure their correct ID size, OD and length. You only need to know two of the three axis values to determine the third value, draw a straight line between the known values and extend the line to determine if the flow rate and flow velocity are at acceptable levels.
When replacing an existing hydraulic hose with a new one that has a smaller internal diameter, the same amount of fluid that flowed through the original, larger hydraulic hose is now passed through the new, smaller one. Flow rate is an important consideration here, as it is measured in gallons per minute (GPM) and is determined by the volume of hydraulic fluid produced by the hydraulic pump over a specific period of time. Changing the flow of the hydraulic pump but leaving the same size of the hydraulic hose will affect its flow rate. To calculate flow velocity, you need to use a constant, such as the cross-sectional area of the hose and the flow rate of the hydraulic pump with a flow meter.
While it may be convenient to replace an existing hydraulic hose with one that has a different size than intended for that particular system, it can cause unwanted damage and result in equipment inefficiency. The temperature of the fluid has been empirically related to a significant reduction in the life of hoses, so reducing their size can also cause system downtime. To avoid this, it's best to rebuild your hose assembly using a smaller hydraulic hose with a smaller connector. Using Gates' nomographic chart can help you identify which size and length of tubing is best for your hydraulic system.
It's important to consider all factors when selecting your tubing, including ID, OD, length, flow rate and velocity. This will ensure that your system runs efficiently and effectively.