The main factors affecting the sealing performance of hydraulic valve
June 21, 2019
The main factor of damage to the sealing element is the impurities in the working fluid. These contaminants grind between sealing elements, causing the valve to leak. Therefore, foreign countries have put forward the corresponding level of hydraulic components, the filter should be the appropriate accuracy. They think that 5μM oil seal components, with filter accuracy of 3 / μM filter life expectancy than with 10μM increased 10 times. But the hydraulic support valve, the working environment is very poor. In coal mining face, tubing length of more than 1,000 meters, up to more than 4,000 connector socket, tank no special dust-proof facilities. Emulsion has a large number of floating impurities in the cylinder bottom and the valve cavity, leaving more coal, rock and iron filings. Intake valve plug and seat, due to more frequent opening and closing, high liquid flow, the seal will soon fail. It has proved very difficult to reduce the contaminating impurities in the hydraulic system of the scaffold. It has been envisaged to use a high-pressure filter at the emulsion pumping station while adding a small filter at the inlet of each scaffold. However, it was quickly blocked up at work, resulting in a stoppage. On the other hand, with the development of hydraulic support technology. The use of valve performance and valve life put forward higher requirements. Currently, with a 120-mesh filter and a magnetic filtration unit, the life of the hydraulic valve is measured by the total flow rate of the emulsion through the valve under test and the number of valve opening and closing. But in fact the indoor type test and the actual results of underground work vary greatly. In many countries, formal tests have increased anti-pollution requirements. Some have incorporated proper pulverized coal in emulsion and some have added mechanical impurities. To this end, the need to use the new, anti-pollution ability, suitable for working conditions downhole seal. Hydraulic support hydraulic valve life is very low, foreign solutions and ways to improve the system's filtration accuracy and improve the quality of emulsion, but with little success. This article analyzes the development process of the seal pair of the holder valve, discusses the relationship between the material of the seal pair and the sealing performance. It is pointed out that the sealing technology is the key to improve the service life of the hydraulic valve in hydraulic support.
