FAQ
Q1: What is a medium-pressure single-pipe return oil filter? What is its main function?
A1: The medium-pressure single-pipe return oil filter is a crucial filtration device installed on the return oil pipeline of the hydraulic system (with a pressure typically ≤ 4.0 MPa). Its core function is to serve as the "final barrier" for system contamination. Before the oil flows back to the oil tank, it efficiently filters out metal particles resulting from wear in the system, debris from seals, and external contaminants that have invaded, keeping the oil in the oil tank clean. This helps protect the hydraulic pump and other precision components, and extends the lifespan of the entire system.
Q2: How do I select the appropriate return oil filter for my system?
A2: The selection mainly depends on three key parameters:
1. Working pressure and flow rate: Ensure that the rated working pressure (e.g., 4.0 MPa) and nominal flow rate (L/min) of the filter are greater than or equal to the actual maximum value of the system's return oil path.
2. Filter accuracy: Choose based on the cleanliness requirements of the system (e.g., ISO 4406 grade). Common accuracies include 10 μm, 20 μm, etc. Higher accuracy provides stronger protection, but the flow resistance also increases accordingly.
3. Connection method and size: It needs to match the existing return oil pipeline interface (such as flange standard DN*, or thread specification).
Q3: What are the precautions when installing the return oil filter?
A3: When installing, please note:
• Installation location: It should be as close to the oil tank as possible, and installed downstream of all the actuating elements (cylinders, motors) in the system.
• Flow direction: Make sure that the oil flows in the same direction as indicated by the arrow on the filter housing.
• Maintain space: Reserve sufficient space to facilitate future inspections and replacement of the filter element.
Q4: How can one determine when the filter element needs to be replaced?
A4: The following methods can be used for judgment:
• Visual indicator: Most filters are equipped with a mechanical visual indicator (a red push-button). When the filter element becomes clogged and the pressure difference increases to the set value (usually 0.35 MPa), the indicator will pop out or display red, indicating that replacement is necessary.
• Electric transmitter: Some models are equipped with differential pressure switches, which can output electrical signals to the control system to achieve remote alarm functionality.
Regular maintenance: Even if there is no notification, it is recommended to carry out preventive replacements based on the equipment maintenance cycle (such as after 2000 hours of operation).
Q5: What consequences will occur if the clogged filter element is not replaced in time?
A5: If the filter element is severely clogged, it will cause poor oil return, which may lead to the following problems:
1. Back pressure increase: It will increase the resistance of the system's oil return, possibly resulting in slow movement of the actuating elements, damage to the seals, or an increase in oil temperature.
2. Filter bypass: To prevent system damage, the filter has a built-in bypass valve that will open when the pressure difference is too high. However, at this time, the unfiltered dirty oil will directly enter the oil tank, causing the entire filtration system to fail, and contaminants will circulate in the system, accelerating the wear of all components.
Q6: Can disposable filters be cleaned and reused?
A6: Absolutely not recommended. For deep-type filters made of materials such as paper or glass fiber, their filtration mechanism relies on tiny pores to intercept particles. Once clogged, cleaning cannot completely restore their original pore structure and filtration accuracy. Reusing them will seriously affect the filtration efficiency, equivalent to having an ineffective filter operate, which is extremely risky. New original or certified qualified replacement filters must be replaced.
Q7: Do your filters offer different filtration accuracy and connection options?
A7: Yes, we provide comprehensive customized selection services. We can supply various filtration accuracies (from 3μm to 25μm), different flow specifications, and oil return filters that are compatible with various standards (such as Chinese standard, American standard, European standard) such as flange or threaded interfaces. Please provide your system parameters, and our technical team will recommend the most suitable model for you.
