As machines get bigger and workloads increase, the operating pressures within these hydraulic systems in also increasing. These pressures put more strain on hydraulic fluid hoses, joints and in particular seals.
When a hydraulic hose bursts during operation, the results can be spectacular. Hundreds of litres of hydraulic fluid can be discharged into the workplace in a matter of seconds, proving potentially dangerous to personal as well as the surrounding environment.
According to estimates from hydraulic hose manufacturer Gates, around 370 million liters (98 million gallons) of hydraulic fluid is estimated to leak from hydraulic equipment every year globally.
But it would be wrong to think that all hydraulic fluid is lost through catastrophic hose ruptures. Indeed, a significant portion of the 370 million litres is lost through very small leaks, for example, around hydraulic ram seals and various system couplers. These may be extremely small, and yet a leak producing just one drop of oil per second results in the loss of about 1,500 litres of hydraulic oil per year. Whilst these leaks might not be considered as dangerous to the health of employees as a burst hose, nevertheless, they can prove to be a hazard to the environment, not to mention the cost of replenishing the hydraulic oil.
When a hose bursts, it’s not difficult to identify where the problem has occurred; it manifests itself very visibly! However, when extremely small leaks are encountered, identifying the source of the problem is often the most difficult task. The fluid has often soaked the surrounding area and will simply be dripping from the lowest component on the system, as gravity takes its course, rather than from the source itself.
There are further issues to be considered in very high-pressure systems. In such systems, for example, above 200 bar, when a seal or hose develops a micro-crack the oil escapes at extremely high velocity, and if the pressure is high enough the oil can atomise and form a fine mist or aerosol, making detection with the naked eye more difficult. These types of high-pressure systems are more commonly found in heavy-duty industrial, mining, aerospace, and energy applications where high force, precise control and durability are required.
Such leaks can prove to be not only costly but extremely dangerous. Atomised standard hydraulic fluid is easily ignited, resulting in an out-of-control fire and potentially even an explosive environment.
Early detection of such leaks is key. Micro-cracks in seals, hoses and other components can often progress into much larger leaks that require prolonged periods of unscheduled downtime. Whilst the cost of this varies depending on the operation, unscheduled downtime is inevitably expensive. For example, in a large mine, the cost of shutdown can typically be $500,000 per hour. So it’s not difficult to understand why operators prefer to identify potential problems in embryo so they can be rectified during a planned maintenance operation.
Recently, operators using high-pressure hydraulic equipment have reported on the ability of acoustic imaging cameras being able to identify and locate such leaks. Leaks that would otherwise have been difficult to locate with traditional detection methods and certainly not visible to the naked eye.
Teledyne FLIR is a global company well known for its research and production of high-quality thermal and acoustic imaging cameras. The pinnacle of their acoustic imaging line is the highly acclaimed FLIR Si2.
This advanced acoustic imaging camera contains highly sensitive microphones capable of detecting sounds over a wide frequency range, namely 2–130 kHz. However, it’s not just the frequency range that sets the FLIR Si-2 camera above the competition. The camera onboard AI coupled with exceptional sensitivity has proven to be a substantial advantage when detecting air, gas, steam or high-pressure hydraulic leaks.
It is this instrument, well established in the field of gas detection, that is now being used by customers to identify fluid leaks in high-pressure hydraulic systems.
Images captured by the 12-megapixel camera are displayed on a new high-definition five-inch 1280 x 720 screen which is brighter and sharper than its predecessor. The 8x zoom feature also allows more distant problem areas to be brought into focus.
To find out more about the FLIR Si2-series of acoustic cameras or to arrange an onsite demonstration please contact your local FLIR agent or distributor.
