Pressure is a crucial factor in hydraulics. You’ll see burst pressure and working pressure as the ratings for hoses. Working pressure is how we identify the correct hose for your application based on the hydraulic pressure. It is critical that the system pressure never exceed a hose’s working pressure. Burst pressure is the maximum pressure a hose can take before a catastrophic failure. This is an important safety factor. Burst pressure is usually four times the working pressure but you should always be aware of the manufacturers’ rating.
It is critical to know the full range of hydraulic pressures in your equipment when replacing any hose assembly. The relief-valve provides a good estimate for the maximum pressure during work. Any modifications to equipment should be taken into account because this can cause pressure surges that are significantly higher than the relief valve setting. We have diagnostic tools to measure pressure spikes.
The working pressure should always be greater than or equal to the highest system pressure including spikes and surges. A hose that is exposed to pressure higher than its working pressure will fail and have a drastically reduced lifespan. This can cause a work stoppage and shut down your operations.
If you notice rubbing or bending on any hydraulic assembly, it is a good idea to see if the routing or angles can be changed to eliminate this issue.
Differences in pressure between inlet and outlet can reduce system efficiency.
Common Causes:
- Friction: Fluid rubbing against hose walls (at bends) can reduce flow rates
- Viscosity: Lower fluid viscosity is harder to move
- Fluid Temperature: Higher temperatures cause hydraulic fluid to thin so it flows faster
- Hose ID: Size affects fluid for a given flow right. Higher velocities result in more pressure drops. A larger ID reduces pressure drop.
- Flow Rate: Pressure drop increase with flow rate for the same hose size
- Heat Gain: System Efficiency and Horsepower Loss are greatly affected by turbulent flow
Controlling pressure is the key to an efficient and well working piece of equipment.