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Zhangjiagang city sinochem mechanical seal co., LTD
Address:Zhangjiagang cityof nahuy road industrial development zone
Tel:086-0512-58670570
Fax:086-0512-58185129
Contact Person:MR
Zip Code:215636
Website:www.zhjxmf.com
E-mail:webmaster@zhjxmf.com
Technical guidance
The working principle of mechanical seal
Mechanical seal is to rely on a pair or number of perpendicular to the axis as the relative sliding face in fluid pressure and compensation mechanism of elastic (or magnetic force) under the action of keep posted combined with auxiliary seal and resistance to leakage of shaft seal device.
Mechanical seal structure is commonly used by the stationary ring (1) static ring, rotating ring (ring) 4, 2, 3 elastic element, spring seat tight set screw, rotating ring auxiliary seal ring 5 6 and static ring auxiliary seal 8 components, such as stop pin 7 fixed on the gland 9 in order to prevent the static ring rotation. Rotating ring and static ring often can also be based on whether they have axial compensation ability and called compensation ring or the compensation.
Mechanical seal in the fluid may leak path has A, B, C, D four channels.
C, D leak path are static ring and the sealing between the gland, and shell, both static seal. B channel is between the rotating ring and shaft seal, when the friction and wear, it can only follow the compensation ring along the axial trace mobile, in fact is still a relatively static seal. As a result, the leakage passage is relatively easy to block. Static sealing elements are the most commonly used rubber o-ring or ptfe V circle, as the rotation of the compensation loop auxiliary seal ring or stationary ring, sometimes use both elastic element function of rubber, ptfe or metal corrugated pipe structure.
A channel is the rotating ring and static ring end face each other cooperation relative sliding dynamic seal, it was the primary seal, mechanical seal device is to determine the key of mechanical seal performance and life. Therefore, the processing requirements for the seals is very high, at the same time in order to keep the seals between the necessary lubricant film, must strictly cavity pressure per unit area on the face, the pressure is too big, not easy to form stable lubricant film, will accelerate wear end surface; The pressure is too small, leakage increase. So, in order to get a good sealing performance and have enough life, in the design and installation of mechanical seal, make sure face pressure value per unit area in the most appropriate scope.
Compared with soft packing seal, mechanical seal has the following advantages: (1) sealing is reliable in the long period running, sealing condition is stable, leakage is very small, according to rough statistics, the general is only 1/100 of the soft packing seal leakage; (2) the service life is long in oil, water type of media generally can reach 1 ~ 2 years or longer, usually in the chemical medium can reach more than half a year; (3) low friction power consumption of mechanical seal friction power is only 10% ~ 50% of soft packing seal; (4) the shaft or shaft sleeve is basically not affected by friction losses; (5) after the maintenance cycle is long face wear can be automatically compensated, in general, no regular maintenance; 6. Good vibration resistance Of the vibration of the axis of rotation, the deflection and axis deflection is not sensitive for seal chamber; 7) wide range of mechanical seal can be used in low temperature, high temperature, vacuum and high pressure, different speed, and all kinds of corrosive medium and containing abrasive medium such as seal. But its shortcomings are: (1) the structure is complex, high requirements for manufacturing processes; (2) to install and replace more troublesome, and ask the workers have certain installation technical level; (3) accident accident, dealing with difficult; (4) a one-time investment is high.