Noise reduction in hydraulic systems often requires the isolation of the pump/prime-mover assembly using flexible mounts known as isolators. This isolation is maintained by utilizing hose connections between the pump/prime-mover and the rest of the system.
However, it’s important to note that while long lengths of hose can diminish structure-borne noise, they are proficient radiators in the frequency range where most energy is generated, typically around 600, 900, and 1200 Hertz.
Regarding vibration and noise conductivity, a long length of pipe or tube is the least favorable configuration. Although better than pipe or tube, a long length of hose still poses drawbacks. Optimal noise reduction is achieved with one section of pipe or tube connected to one section of hose. The most effective configuration entails one section of pipe or tube with a section of hose on each side, forming hose > tube > hose.
Consequently, forces are exerted on connecting structures. To mitigate noise when bending hose, solid bends (90° or 180°) with hose sections on either side are recommended.
For instance, during testing, a Car Lift Repair Tampa Florida hydraulic power unit with a 150-gallon reservoir and a 40 GPM piston pump running at 1200 rpm and 750 psi exhibited a noise level of 88 dB(A). By reconfiguring the pressure hose into two hoses separated by a 90° swept elbow, the noise level decreased by 5 dB(A).
While a 5 dB(A) reduction might seem insignificant, the logarithmic nature of the decibel scale translates to a 44% reduction in sound pressure and a 68% reduction in sound power. This demonstrates the effectiveness of adjusting the pressure hose configuration, which is simpler, cheaper, and easier to implement compared to alternative noise reduction measures such as increasing mass or installing isolating mounts or acoustic filters.
Car Lift Repair Tampa Florida Hydraulic oil leaks were once commonly accepted as a natural aspect of hydraulic machinery. However, with advancements in sealing technology and the evolution of reliable connection systems, achieving leak-free hydraulic plumbing is now easily attainable.
The foundation of leak-free reliability lies in the careful selection of hydraulic fittings during the design phase for port, tube-end, and hose-end connections.
Ports – Car Lift Repair Tampa Florida Connectors featuring elastomeric seals such as UN O-ring, BSPP, and SAE 4-bolt flange provide the highest seal reliability. On the contrary, NPT and BSPT connectors are less reliable for high-pressure hydraulic systems due to the tapered thread, which inherently creates a leak path. In existing systems, tapered thread connections should be replaced with UN O-ring or BSPP connectors to ensure leak-free reliability.
Tube and Hose Ends – While ORFS tube and hose end connections offer high seal reliability, their cost limits their widespread use compared to compression fittings and JIC 37-degree flare connections.
Although Car Lift Repair Tampa Florida lared connections are popular for their simplicity and affordability, the metal-to-metal seal of the flare does not always guarantee a permanent, leak-free joint, especially in tube-end connections. However, the use of a purpose-built seal developed by Flaretite can eliminate leaking flare joints. The Flaretite seal, a stainless steel stamping with concentric ribs containing pre-applied sealant, crushes between the joint faces upon tightening, ensuring a leak-free joint by eliminating misalignment and surface imperfections.
Incorrect Torque – Improper torque application is a common cause of leaks from flare joints. Insufficient torque leads to inadequate seat contact, while excessive torque can damage the tube and fitting through cold working.
Vibration – Vibration can stress plumbing, affecting hydraulic connector torque and inducing fatigue, with tubes being more susceptible than hoses. Addressing the root cause of excessive vibration is crucial, ensuring proper support for all conductors, and replacing problematic tubes with hoses if necessary.
Seal Damage – While hydraulic fittings with elastomeric seals offer numerous benefits, their reliability hinges on maintaining fluid temperature within acceptable limits. A single over-temperature event of significant magnitude can damage all seals in a hydraulic system, resulting in multiple leaks.
Leaks are frequently the primary maintenance concern encountered with hydraulic equipment. However, while this perception may have held true four decades ago, advancements in sealing technology and the evolution of dependable connection systems have rendered leak-free hydraulic systems highly attainable today.
Establishing reliable connections is paramount for achieving leak-free operation, ideally commencing at the design phase when selecting hydraulic connections for port, tube-end, and hose-end connections.
Ports – Car Lift Repair Tampa Florida Connectors incorporating elastomeric seals such as UN-O-Ring, BSPP, and SAE 4-bolt flange provide the highest seal reliability. Conversely, NPT connectors are the least reliable for high-pressure hydraulic systems due to the thread’s inherent leak path. The deformation of threads during tightening results in an increased potential for leaks with subsequent loosening or tightening. Hence, NPT connections are unsuitable for high-pressure hydraulic systems.
Tube and Hose Ends – Flared connections, notably the JIC 37-degree flare, have gained widespread acceptance due to their simplicity and cost-effectiveness. The JIC flare is globally renowned for its ease of fabrication, broad size range, adaptability from imperial to metric, and widespread availability. However, the metal-to-metal seal of the flare does not consistently guarantee a permanent, leak-free joint, particularly in tube-end connections. As hydraulic system operating pressures have risen, flared connections have become more prone to leaks, resulting in the contamination of systems with dirt and sludge.
Alternative Car Lift Repair Tampa Florida hydraulic connectors, particularly the ‘O-Ring Face Seal’ (ORFS), are gaining acceptance in the industry. ORFS tube and hose end connections provide high seal reliability through the use of an elastomeric seal. However, ORFS connectors come with certain drawbacks: they are larger in size, offer fewer adaptor options, require precise alignment during installation to prevent O-ring extrusion, and are typically twice the cost of flared connections. Consequently, ORFS is not as widely adopted as compression fittings and the 37-degree flare.
To address leaking flare joints, a Car Lift Repair Tampa Florida conical washer can be installed between the JIC nose and flare. Flaretite manufactures one type of flare seal, consisting of a stainless steel stamping with concentric ribs containing pre-applied sealant. Upon tightening, the ribs crush between the joint faces, eliminating misalignment and surface imperfections. See inset for details on the JIC 37-degree seal washer (Flaretite).