![]() Individual element manufacturers determine the Beta Ratio specification for their elements. The ISO 16889:1999 standard for multi-pass testing states that this test is applicable for filter elements that exhibit an average Beta Ratio greater than or equal to 75. In most instances, the multi-pass test is completed when the element differential pressure reaches the specified limit or the Beta Ratios fall below a specified level.īeta Ratios for filter elements are determined during the multi-pass test as outlined above. This cleaned fluid is contaminated again by the injection fluid, and is once again pumped to the test filter.ĭuring the test, the element differential pressure, the upstream and downstream particle counts and the amount of injected contaminant are continuously monitored. The test solution is filtered by the element under test and travels back to the test reservoir (along with any unfiltered particles). This test solution is circulated continuously to the test filter at a constant flow rate. The fluid in the injection reservoir is then pumped continuously into the clean fluid in the test reservoir, thereby creating a low concentration test solution. Test dust of a known particle size distribution is added to the fluid in the injection reservoir until it reaches a specified concentration in grams of contaminant per liter of test fluid. The test measures the particulate removal efficiency as it relates to the ingression of dirt particles creating increased differential pressure over element life (Beta Stability). ![]() The purpose of the multi-pass test standard is to have a lab-based procedure that will provide reproducible test data that can be used to evaluate the dirt-holding capacity and the particulate removal efficiency (Beta Ratio) of a hydraulic fluid power filter element. The equipment user may then have to add filtration to achieve the required system performance after the system is purchased, installed and operating. This is an easy way to lower the overall system price. System suppliers and purchasers often change the filter strategy by changing the filter size, micron rating and the number of filters. The good design intentions of the application design engineers are often overridden by the sometimes more powerful dictates of price and competition. Likewise, the ability to change the filter on the run - often requiring the use of a duplex arrangement - is an important preinstallation consideration. The correct number and type of filters required must be taken into account early in the system design phase. The constantly increasing demands made on hydraulic components means that today’s systems must be equipped with filters that have a high rate of particle removal efficiency at the required micron rating. While price and delivery are important considerations, filter element performance should be the major deciding factor. ![]() The high cost of component repairs and system downtime can be kept to a minimum only through a preventive maintenance program that includes using and maintaining the proper system filtration. High levels of solid contamination are usually the result of inadequate filtration.Įffective filtration in hydraulic systems prevents breakdowns and increases the life expectancy of important and expensive components. Investigations into the causes of breakdowns in hydraulic systems have shown that the majority of hydraulic-related failures can be attributed to high levels of solid contamination in the fluid.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |