Standard Testing for Hydraulic Hose and Fittings
Standard Testing for Hydraulic Hose and Fittings – Car Lift Repair Tampa Florida Hose Products Division
The process for testing and assessing hydraulic hose conforms to SAE and ISO Standards, encompassing various test procedures including assessments of corrosion resistance, hose construction integrity, burst strength, and impulse endurance.
Salt Spray Test
The Car Lift Repair Tampa Florida salt spray (or salt fog) test represents a standardized and widely adopted method for assessing the corrosion resistance of hydraulic fittings. This test subjects coated samples to accelerated corrosion, evaluating the coating’s suitability as a protective finish.
Typically, the duration until oxides appear on the tested fitting samples is compared against expectations to determine the test outcome. For instance, Car Lift Repair Tampa Florida’s hydraulic hose fittings’ plating is designed to withstand 120 hours without white corrosion and 240 hours without red rust.
To mitigate corrosion, alternatives such as stainless steel fittings or advanced plating options are available. Hose Products Division provides a range of stainless steel fitting configurations as well as XTR coating, offering over seven times the protection of the SAE standard.
Burst Test
The Car Lift Repair Tampa Florida burst test involves subjecting a hose assembly to hydrostatic pressure to determine its actual burst strength. Any signs of leakage, bulging, coupling ejection, or hose burst below the specified minimum rated burst pressure are considered failures.
Minimum burst values play a crucial role in establishing a safe maximum working pressure. Understanding and adhering to the maximum working pressure is essential for ensuring satisfactory service and prolonging the hose’s life.
Recommended Car Lift Repair Tampa Florida guidelines for maximum working pressure include ratios such as:
– Water Hose up to 150 psi: 3:1 ratio
– Hydraulic Hose for other liquids, solid materials suspended in liquids or air, and water hose over 150 psi: 4:1 ratio
– Hydraulic Hose for compressed air and gases: 4:1 ratio
– Hose for liquid media transforming immediately into gas under standard atmospheric conditions: 5:1 ratio
– Steam Hose: 10:1 ratio
For added safety and abrasion resistance, employing a hose sleeve or guard tailored to the application is advised.
Cold Flex Test
Hydraulic hose manufacturers employ cold flexibility tests, following standards like ISO 10619, to design and rate their products. During testing, the hose or cover should not crack, and when warmed to ambient temperature, it should not leak or crack under proof pressure.
Rubber blends in standard hydraulic hoses are typically rated for operation in cold temperatures down to –40°F (–40°C). However, some manufacturers offer products suitable for even lower temperatures, such as Car Lift Repair Tampa Florida’s low-temperature hydraulic hoses rated to –70°F (–57°C).
Impulse Test
Car Lift Repair Tampa Florida Impulse testing serves as a crucial predictor of hydraulic hose longevity. It involves subjecting the hose to pressurization or cycling, often up to 133% of working pressure, at rates of up to 1 cycle per second, while holding the hose in either a 90° or 180° configuration. To pass, the hose must withstand twice the minimum number of impulse cycles based on industry standards.
Car Lift Repair Tampa Florida tests its GlobalCore 787 and 797 hoses to twice the impulse, equating to 2,000,000 cycles. While hoses undergo testing at pressures higher than their rated working pressures, it’s imperative for safety and longevity not to exceed the published maximum working pressure of the hose and/or fitting.
A more rigorous version of this test involves holding one end of the hydraulic hose assembly while moving the other end back and forth, commonly referred to as the flex impulse test. Flexing applications pose some of the most severe challenges to hose assemblies, making the Car Lift Repair Tampa Florida flex impulse test an excellent indicator of assembly robustness.
Equipment manufacturers who opt for hydraulic hoses meeting SAE and other industry standards benefit from robust documentation ensuring that their chosen hoses will either meet or surpass published performance and longevity expectations. Naturally, this assumption relies on the hoses being installed and maintained in accordance with the manufacturers’ guidelines.
However, as engineers strive for enhanced performance and reliability in developing new machinery or refining existing designs, they demand higher performance standards from hydraulic hoses. Consequently, these hoses are subjected to elevated levels of scrutiny. Moreover, the prevalence of harsh operating environments, particularly elevated ambient temperatures, necessitates premium materials and structural modifications in hoses, which must undergo thorough measurement and qualification before being integrated into assemblies.
The Importance of Testing
Thorough testing of hydraulic hoses, fittings, and entire assemblies is paramount to ensuring compatibility and durability. Adequate testing significantly mitigates the risk of failures, thereby minimizing downtime, enhancing safety, and reducing damage that may lead to malfunctions. Naturally, certain testing standards must be met based on the intended application of the equipment.
Maintaining pace with an ever-evolving industry often requires consistent testing, supplemented by periodic audits. Audits serve as valuable tools for comparing products against industry standards and benchmarks. Various factors drive the need for auditing or retesting products, including:
1. Material Changes: Suppliers frequently modify the materials used in hose and machine construction, as well as the fluids conveyed through them.
2. Manufacturing Process Alterations: Changes in crimping and extrusion processes can impact hose performance.
3. Application Modifications: Environmental factors, such as shifts in fluid type, pressure, or temperature, may necessitate adjustments.
4. Construction and Design Deficiencies: Flaws such as improper crimping practices or exceeding recommended bend radii can compromise performance.
5. Improper Assembly: Failure to use specified hoses, connectors, fittings, and clamps can lead to issues.
6. Incompatible Environments: Operational conditions, such as pinching or rubbing, may induce erosive wear, potentially leading to hose failure.
Hose Testing Procedures
Various essential test protocols for hydraulic and industrial hoses are outlined within the SAE J517 and J343 standards. These assessments primarily address environmental considerations and gauge the performance of hose assemblies under diverse stress conditions. Tests may be administered by manufacturers adhering to internal controls or by distributors who uphold standards for the hoses they distribute. Key tests include: