How choose of filter clean and filter element
General Qualified oil filter must meet the original design of the engine cylinder pressure, oil temperature and flow rate, viscosity and vehicle usage conditions, and to consider the overall balance of filter element quality. Hydraulic oil filter product samples or the nameplate label is the name of filtering accuracy at the manufacturer, rather than absolute filtering accuracy, only through experimental value β measured to represent the filter tribute filtering capabilities. Hydraulic oil filter should also meet the requirements of the pressure loss (total differential of pressure filter is less than 0.1PMa, total pressure of return oil filter difference is less than 0.05MPa) in order to ensure optimal of flow and filter element life.
When the selection of filter clean (filter element) can be used the original pieces,and can also choose the second brand. It should be noted that: to be acceptance of the selected filter element, test whether it meets should have the performance indicators.
一、the air filter
Optional air filter must be power, economy and reliability match with the original engine.
(1) Nominal amount of intake air
filter element technology parameters for air chlorine flow rate should be greater than engine the rated intake air.
(2) filter material
Filter material thickness, tensile strength, the original intake resistance, filtration precision requirements and so on. Import diesel requirements of air filtration accuracy of 5μm, domestic diesel must also be less than 20μm. High efficiency filter filtration accuracy of 2μm, ordinary import of filter paper to 30μm, while the domestic filter is only 80μm.
二、diesel oil filter
Diesel filter according to ISO4020 standard (Road vehicles - diesel used fuel filter test method) the following tests.
1. The new filter cleanliness of test: determine the filter inside whether to clean the dust impurities at production and storage
2. The Bubble Technique test: used to confirm the filter element whether there is greater than the filtration accuracy for pore exist.
3. filtration efficiency and life testing: filtration efficiency is determination of filtered out of the percentage of specific particles, the filter life to plug the test pressure is greater than 0.07MPa time representation.
4. The water separation validity test: determine of oil filters separation oil and water percentage of mixture moisture.
5. filter element breakage test: determining resistance to fracture pressure of filter element.
6. The oil filter assembly breakage test: Determination of the total withstand internal pressure for capacity.
7. fluctuating pressure fatigue test: measured at pulsating pressure (simulated engine start or stop time) Oil filters assembly of the mechanical strength.
8. Vibration Fatigue Test: determine the oil filter anti-vibration mechanical strength at the normal under conditions.
Full-flow oil filter should be ISO4548 standards for the following test.
1. Pressure drop - flow rate characteristics test: used specified viscosity engine oil to determination of total pressure drop - flow curve.
2. Filter pass elements experimental: Determination of the filter pressure drop - bypass flow curve.When through a low pressure drop of the filter, to limit the oil amount of unfiltered. When the bypass element is less than the predetermined opening pressure drop, allowing a small oil amount; and when the filter is completely blocked, can pass all traffic but not exceeds a predetermined pressure drop.
3. The high pressure drop and high temperature performance test: the oil filter at work (especially in the filter clogged) to withstand high pressure drop.In addition, the filter also affected by the impact of engine oil temperature,it should test the filter affordability pressure drop without damage at under simulated high temperature conditions.
4. The filter life and filter efficiency test: used particle counting method to determination of the filter life, the test draw pressure-test time or pressure - plus ash weight curve to achieve of bypass valve designed to open pressure for test time or contaminants are expressed as weight filter life.
5. The cumulative efficiency test: the determination of filter life by gravimetric analysis,in order to achieve the test end of pressure test time or contaminants catches to assessed.