Metal Bellows Seals reliability
Mechanical seals are widely used in rotating and moving equipment such as pumps and stirred tanks. Conventional spring-type mechanical seal because the structure is simple, cheap, easy to use, the basic sweep of the conditions under the conditions of -15 ~ 150 ℃; if the material is allowed to be cooled, between 150 ~ 200 ℃, you can also use spring Mechanical seal; and bellows mechanical seal in more than 200 ℃ or - 50 ℃ below the field is widely used. The reason why this is because in the high (low) temperature conditions, the spring-type mechanical seal of the auxiliary seal will fail, such as rubber material auxiliary ring will occur at high temperatures aging, at low temperatures will appear brittle phenomenon; The fluoroethylene auxiliary seals are thermally deformed at high temperatures and have a cold flow at low temperatures, so that metal bellows mechanical seals have to be used at extreme temperatures. In fact, the metal bellows mechanical seal without auxiliary dynamic seals, relative to the spring-type mechanical seal to reduce the leakage point, the reliability significantly improved for the shaft seal advantage. But the bellows mechanical seal manufacturing cost is relatively high, affected by economic factors, metal bellows mechanical seal application is limited to high temperature or low temperature working conditions, did not fully play the advantages of high reliability. In recent years, metal bellows manufacturing technology developed rapidly, many domestic manufacturers are able to manufacture, therefore, metal bellows mechanical seal prices have declined, which also promoted the metal bellows mechanical seal in general temperature conditions Applications. The author in different occasions at room temperature application of metal bellows mechanical seal to achieve better results, that the metal bellows mechanical seal in some special conditions is worthy of promotion.
Metal bellows mechanical seal because there is no auxiliary dynamic seals, reducing the leakage point, the relative increase in reliability. Change the traditional concept, in some specific room temperature media using metal bellows mechanical seal, you can achieve a satisfactory sealing effect. In the cost is better than the spring mechanical seal, the promotion of the use of metal bellows mechanical seal is worth it. Mechanical seal is one of the most complex mechanical base components of precision and structure. It is a key component of various pump, reaction mechanical seal synthesis tank, turbine compressor, submersible motor and so on. The sealing performance and service life depend on many factors, such as selection, machine accuracy, proper installation and so on.
The mechanical seal is a sealing device which is composed of two sealing elements (static ring and moving ring) which are perpendicular to the shaft, smooth and the surface of the mechanical seal is aligned with each other and is rotated relative to each other. It is by the pressure of the sealing medium in the rotation of the dynamic ring ring on the contact surface (end face) to produce the appropriate compression force, so that the two ends close together, the end between the maintenance of a thin layer of liquid membrane to seal The purpose of. This layer of liquid film with liquid dynamic pressure and static pressure, play a role in the balance of lubrication.