Abstract: Hydraulic support hydraulic valve in the life of a very low solution to foreign ways and means to improve the filtration system and improve the quality of emulsion, but with little effect. 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 hydraulic valve in hydraulic support. Hydraulic support is a supporting device in coal mining machinery. After overhauling it, it can be used for five years underground. However, the service life of various hydraulic valves in hydraulic support is very low. For a long period of 3 months and a short period of only a few weeks, Foreign solutions and ways to increase the filtration system to improve the quality and improve the quality of the emulsion, but with little success. To a British hydraulic valve, for example, although the processing accuracy and filtration of the entire hydraulic system are relatively high, but because of low life expectancy, has been facing the elimination of our country. A main factor affecting the sealing performance of the hydraulic valve The main factor of damage to the sealing element is the working fluid impurities. 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. At present, the life of a valve is measured using a total flow rate of the emulsion through the valve under test and the number of valve opening and closing operations, with a 120-mesh filter and a magnetic filtration device. 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. 2 history and status of the hydraulic valve seal material Leakage of the spool and valve seat contact surface, is the result of squeezing the working liquid molecules. Affect the sealing effect is the main reason for the spool and valve seat contact pressure, unevenness and pressure. When the valve core and the valve seat to P surface of the joint pressure, the working liquid molecules to force F squeeze, the sealing material will have elastic deformation. If the seal of the total resistance greater than the molecular repulsion, the seal effective, otherwise it will form a leak. Early hydraulic support, there is no other seal between the movement, is a metal direct contact seal, which requires seal contact surface match, with high processing accuracy, or must increase the sealing pair of bonding force, the contact surface of plasticity Deformation, blocking the leak channel.
Sodium Hexametaphosphate,Sodium Hexametaphosphate Shmp,Shmp Sodium Hexametaphosphate,Chemicals Sodium Hexametaphosphate
Henan Chuange Industry CO.,LTD , https://www.chuangegroup.com