Hydraulic power offers a highly effective way of transmitting large forces. Better yet, since hydraulic systems use fluid to transfer force, they offer a degree of design flexibility that other power systems simply cannot rival. For this reason, hydraulic power plays a key role in the manufacturing, processing, automotive, and aerospace industries.
Yet like all mechanical systems, a hydraulic system may fall prey to inefficiency that can prevent it from achieving its potential. One common source of inefficiency lies in the phenomenon known as pressure drop. If you would like to boost your knowledge of hydraulics, read on. This article outlines three factors that can increase a system's pressure drop.
1. Hose Assembly Length
Pressure drop occurs in virtually all hydraulic systems. The system naturally loses a certain amount of force as the fluid travels from the pump to the output end of the system. But a hydraulic engineer can use special formulas to account for pressure drop to ensure that your system produces the requisite degree of power.
Yet as your system ages and components wear down, pressure drop may increase beyond intended tolerances. The length of your system's hydraulic hoses plays a huge role in pressure drop. Simply put, the longer the hose, the greater the pressure drop it will cause. For this reason, you must ensure that any replacement hoses meet the precise dimensions of the original.
2. Size of Hose
Even if a replacement hose has the exact same length as the original, excessive pressure drop may still occur. The diameter of a given hydraulic hose plays a huge role in pressure drop, since tube size directly affects the velocity of the fluid passing through it.
The relationship between fluid velocity and pressure drop often confuses newcomers to the world of hydraulic dynamics. Most people imagine that slower velocities mean greater pressure drops. Yet actually the opposite holds true. The faster the fluid moves through your system, the more susceptible it becomes to pressure drop.
Smaller hydraulic hoses force fluid into a tighter space, thus increasing fluid velocity. In other words, as the diameter of the hose decreases, the amount of pressure drop increases. To determine the precise amount of hose-related pressure drop, a system engineer needs to know three things: the size of the hose, the fluid velocity set by the hydraulic pump, and the length of the hose.
The designer then plugs these factors into a hose pressure drop table, which tells them the amount of pressure drop for every ten feet of hose. For instance, when hydraulic fluid flows through a hose with a ½" diameter at a rate of 10 gallons per minute, the system experiences a pressure drop of 15 PSI for every 10 feet of hose.
3. Type of Couplings
Pressure drop doesn't just occur inside of your hydraulic hoses. The fittings used to attach hoses to various components play an equally large role. In many cases, a hydraulic hose has to attach to a system component at a 90-degree angle. In order to meet the component's inlet or outlet straight-on, a hose would have to be far longer — a factor that would increase pressure drop even more.
Yet 90-degree fittings may also exacerbate pressure drop problems, especially if the fitting has a hard angle. To minimize the amount of pressure drop caused by 90-degree fittings, you should always select fittings with a sweeping, curved angle. Such fittings tend to reduce pressure drop by 2 to 3 times compared to a hard-angled fitting.
Pressure drop can lead to insufficient power, tool overheating, and other serious problems for a hydraulic system. For more information about how to ensure that your system's pressure drop remains within acceptable levels, contact our experts at Anything On-Site Repair LLC.