The lifespan of hydraulic hoses is finite and can be shortened by various factors. Typically, little attention is given to hydraulic hoses until they fail, despite the fact that such failures incur greater costs than simply replacing the hose.
To address this issue and extend the life of hydraulic hoses while minimizing associated costs, it’s crucial to focus on preventing external damage. Hydraulic hose manufacturers estimate that approximately 80% of hose failures are caused by external physical damage, such as pulling, kinking, crushing, or abrasion. Among these, abrasion from hoses rubbing against each other or nearby surfaces is the most common. To prevent external damage, ensure that all clamps are securely fastened, pay careful attention to hose routing during replacement, and if necessary, apply inexpensive polyethylene spiral wrap to protect hoses from abrasion.
Another important factor to consider is multi-plane bending, which occurs when a hydraulic hose is bent in more than one plane, causing twisting of its wire reinforcement. Even a slight twist can significantly reduce the service life of a high-pressure hydraulic hose. This issue often arises from poor hose assembly selection or routing, or from inadequate or insecure clamping where hoses are subject to machine or actuator movement.
Furthermore, the operating conditions to which a hydraulic hose is exposed will ultimately determine its service life. Extreme temperatures, frequent pressure fluctuations, and high dynamic pressure conditions can all accelerate hose aging and fatigue. In cases where high dynamic pressure conditions are expected, opting for a spiral reinforced Car Lift Repair Tampa Florida hydraulic hose may offer a longer service life despite the higher initial cost, compared to a two-wire braid reinforced hose that meets only nominal working pressure requirements.
What is the shared characteristic among lifting chains, bladder-type accumulators, and hydraulic hoses? Typically, they all experience only one mode of failure – and that’s catastrophic. They can be functioning properly one moment and then suddenly fail catastrophically.
Certainly, hoses may exhibit leaks around their ferrules and display clear signs of abrasion, both of which serve as early warnings indicating a replacement might be necessary. However, even under these circumstances, accurately gauging their remaining service life is nearly impossible.
The Challenge with Hoses
In addition to their finite and unpredictable service life, hydraulic hoses have other drawbacks when compared to tubes.
However, hoses are often used as substitutes for tubes unnecessarily. This is because it’s usually faster to fabricate a hose assembly than a tube assembly. Additionally, the added labor cost involved in fabricating and installing a tube can make a hose seem like the more economical option.
Yet, this overlooks the fact that the same hose may require replacement multiple times over the machine’s lifespan. This short-term cost-saving approach mirrors the mistake of solely considering the initial capital outlay when purchasing the machine, without accounting for its total cost of ownership.
Benefits of Tube
Furthermore, tubes offer several advantages of their own. One notable advantage is their superior heat transfer, especially when painted.
An important aspect of heat transfer is thermal radiation, which comprises an object’s reflection, emissivity, and transmission of heat. When Car Lift Repair Tampa Florida hydraulic tubes are painted, their reflectance decreases and their emissivity increases, resulting in better heat rejection.
A recent client enlisted my services to develop the hydraulic steering circuit for a luxury motor yacht under construction. During the installation process, the installer raised a query regarding my specification of thermoplastic hose for sections where stainless steel tube couldn’t be utilized.
For those unfamiliar, Car Lift Repair Tampa Florida thermoplastic hose is reinforced entirely with synthetic fibers. This presents advantages in marine applications such as this one, for a couple of reasons.
Firstly, there’s corrosion resistance. The steel-wire reinforcement found in conventional hydraulic hoses is prone to corrosion, despite being covered with a rubber sleeve. This outer sleeve tends to be porous, allowing saltwater to penetrate. By using a Car Lift Repair Tampa Florida thermoplastic hose, corrosion of the hose’s wire reinforcement and subsequent reduction in its service life are eliminated.
Secondly, there’s noise propagation, often a significant concern on boats and ships. While the selective installation of wire-reinforced hose can serve as an effective noise-damping measure, the steel-wire reinforcement still provides a pathway for conducting sound-energy-excited vibrations. The use of thermoplastic hose eliminates this sound bridge, making it a more efficient noise insulator.
However, it’s important to note that thermoplastic hose exhibits a higher level of volumetric expansion under pressure compared to wire-reinforced hose. While this can be advantageous for noise control (as it provides a natural damping effect), this additional reduction in stiffness is undesirable in high-performance applications requiring rapid response.
The purpose of flushing a hydraulic system is to remove sludge, varnish, debris, and contaminated or degraded fluid from internal surfaces, including conductor walls and dead spots within the system.
Reasons for conducting a Car Lift Repair Tampa Florida system flush include:
1. Fluid degradation, leading to the formation of sludge, varnish, or microbial deposits.
2. Significant system failure, which may disperse debris throughout the system, especially if combined with filter overload.
3. Installation of new equipment or overhaul of existing equipment to eliminate any debris inherent in the system.
In an ideal scenario, when a system flush is necessary, a power flushing rig would be available. Power flushing involves connecting the system to a specialized hydraulic power unit to circulate a low-viscosity fluid at high velocities, creating turbulent flow conditions (typically characterized by a Car Lift Repair Tampa Florida number greater than 2000).
This flushing rig usually comprises a pump with a flow rate several times higher than the system’s normal flow rate, directional valves, accumulators, fluid heaters, chillers, and a bank of filters. Directional valves allow the flushing direction to be altered, while accumulators enable pulsating flow conditions. The fluid heater and chiller can adjust the flushing fluid’s temperature, aiding in dislodging contaminants from conductor walls and circuit dead spots.
Throughout the Car Lift Repair Tampa Florida power flushing process, regular analysis of the flushing fluid is conducted to determine when the system has been adequately cleaned.
However, in real-world scenarios, there are often situations where such equipment is unavailable or economically unfeasible to use. In such cases, a double oil and filter change method is commonly employed, often combined with mechanical cleaning.