11.2.1 Cleanliness
During the production, storage, transportation and installation of the fuel filter, a large amount of particulate impurities will remain inside it, which seriously affects the normal use of the fuel filter. However, through cleanliness detection, the amount of residual dust and other particles can be visually quantified, and in this way, we can try to improve the cleanliness of the fuel filter, which can reduce the initial resistance of the fuel filter, improve the filtration accuracy, and reduce the pollution and pollution of the fuel system. Component wear increases the service life of the working system.
11.2.1.1 Testing standards and technical conditions
There are international standards, national standards, and industry standards for fuel filter cleanliness tests. Commonly used standards include ISO 4020: 2001, GB/T 5923-2010 (equivalent to ISO4020: 2001) "Automotive Diesel Engine Fuel Filters" Test Method", QC/T 918-2013 "Test Method for Gasoline Filters for Automobiles" and QC/T 772-2006 "Test Methods for Diesel Filters for Automobiles", etc. The test principles of these standards for testing cleanliness are basically the same. Under the specified test conditions, a collector with a filter membrane is installed downstream of the tested fuel filter to collect particulate impurities on the outlet side of the tested fuel filter. Then use a balance to weigh to determine the quality of impurities to determine the cleanliness, and the test methods are similar. However, each standard still has differences in the type of applicable fuel filter and the range of test flow. The industry standard QC/T 918-2013 is generally applicable to gasoline filters for automotive gasoline engines with a rated flow rate below 3.5L/min; while QC/T 772-2006 is generally applicable to automotive diesel engines with a rated flow rate below 3.5L/min And the diesel filter used for the test equipment of diesel injection device can also refer to the diesel filter with a rated flow rate above 3.5L/min: the test standard ISO 4020: 2001 and GB/T 5923-2010 are generally applicable to the rated flow rate Diesel filters for automotive diesel engines and diesel injection device test equipment below 200L/h or diesel filters used for the pressure side and oil inlet side of diesel delivery pumps, for diesel filters with a rated flow rate above 200L/h It can also be used by reference.
At the same time, in order to solve the impact of cleanliness on the performance of fuel filters, relevant domestic industries have formulated a series of technical standards for cleanliness of different types of fuel filters. The technical conditions of the cleanliness of various types of fuel filters such as diesel fine filters and diesel primary filters provide valuable technical support for the production and development of fuel filters used in gasoline engines or diesel engines.
Detection principle 11.2.1.2
The cleanliness test method refers to that under the specified test conditions, a collector with a filter membrane is installed downstream of the tested fuel filter to collect the particulate impurities on the outlet side of the tested fuel filter, and then use a balance to determine the impurities. quality test methods. The cleanliness of the fuel filter can be calculated by the formula W=m2-m where, w, the cleanliness of the tested fuel filter, g; m1, the quality of the test filter membrane, g; the quality of the test filter membrane + impurities, g.
Detection device 11.2.1.3
(1) Cleanliness test device The structure of the fuel filter cleanliness test device is relatively simple, mainly composed of test fuel tank, fuel pump, measuring device, differential pressure gauge and flow meter and other components.
When the fuel filter is tested for cleanliness, the filter membrane that filters and collects impurities inside the fuel filter should be correctly installed in the measuring device shown, the enlarged schematic diagram of the measuring device. In this measurement device, the lining mesh is usually required to be a polyamide test sieve, which is meshed or twill-woven with a pore size of 28um, a fiber diameter of (25+1)um, and a screen through-hole area of 28%.
(2) The test results of auxiliary test devices or equipment cleanliness are determined by weighing with an electronic balance, and there are strict requirements on the test environment, placement method and sampling operation of the filter membrane used to filter and collect impurities, so Generally required test auxiliary devices or equipment include a constant temperature drying oven, an electronic balance with an accuracy of 0.1 mg, a covered porcelain plate for placing a filter, tweezers, a soft brush, and a washing bottle, etc.
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Edited by Jin Tao et al.
Fluid Pollution and Purification Metrology and Tes