Skill Level 1 Standard Machine. An OEM Production machine where the design has been proven to work well under all operating conditions.
Skill Level 2 Repaired Machine. A recently repaired or newly commissioned machine with potential setup issues.
Skill Level 3 Unproven Design. A specialist, custom or new design of machine, or one that is being used in under new environmental conditions.
See all of the potential issues associated with this diagram.
Safety and Environmental risks
Risks to health or the environment for which safety precautions are required or the operators require safety awareness training.
Contamination / Reliability
With over 80% of failures caused by contaminants in the fluid, this section highlights the most common areas where dirt can enter the system, or be generated inside the hydraulic system. It also highlights common faults with sensitive components.
Noise (Low or high-frequency sound, not load judder)
Unusual noises are sometimes the first sign of a problem. Measuring the frequency of the noise is a good way to establish the causes although often measuring the accompanying flow effect or pressure signal will provide more useful information for diagnosing the cause. A low-cost mobile phone spectrum analyser app can help find the key frequencies.
Temperature (Ambient temperatures and heat generation)
Increased or reduced temperatures are often a good way of predicting where faults occur. The reservoir temperature is always critical but measuring pipe temperatures after relief valves, for example, can show if the valve is open or leaking. Keep a record of normal operating temperatures so that you can compare these with new readings later.
Speed (Flow rates and actuator movement)
Timing the speed at which actuators move or sequences switch can give a clear indication that something is wrong. It is helpful to be able to compare faulty actuator timings against a record of original equipment speeds.
Force (Pressure and load affect changes)
If actuators are unable to move the load or respond too harshly then the operating forces are probably not balanced correctly. System load regularly change during operation and often cause complex shock or standby conditions. Pressures can read lower than normal if force issues arise.
Sequence (switching and timing order)
Sequence faults might include equipment operating sequence or timings not performing correctly. This may include an electrical signal, limit switch or pressure sequencing device errors.
Judder/erratic operation (low or high-frequency oscillations of the load)
Harsh cylinder banging, pipes or loads shaking are all indications of hydraulic judder.
Control (when loads are regulated and not just open or shut.)
Servo and proportional systems may suffer from control errors such as positional or force accuracy, hysteresis, speed, or response times etc.
Intermittent (Faults that only occur now and again)
Many faults arise from unexpected or extreme operating conditions that have not been properly protected against. For example, trapped in pressure, shock loads on a cylinder or high and low temperatures are not unusual but are often not fully protected against by the original design. These also include standby or extreme limits, intermittent or exceptional load conditions and undemanded movement.
Efficiency (identifying areas where the energy used can be reduced)
The present climate emergency means it's vital we make every effort to reduce energy consumptions and therefore the burning of fossil fuels. This section will help you identify areas where this may be possible.