The mechanical seal was invented by George Cook and was originally called a "Cook Seal". It was first used in refrigeration compressors. In a short time, it was becoming popular in the industrial proceeding. The demands for the mechanical seals had achieved the value about 1billion dollars.
A mechanical seal is simplified for an end face mechanical seal or a mechanical face seal. It is generally settled in rotating equipment, such as pumps and compressors. The mechanical seal is expected to prevent the liquid leak out of the pump between the rotating shaft and the stationary pump casting. In fact, with the competitive specifications, a mechanical seal does greater help than the mechanical packing which is widely used in the early times.
Generally speaking, a mechanical seal consist of four functional components: primary sealing surface, secondary sealing surfaces, a means of actuation and a means of drive. And the core part of the device is the primary sealing surface which combines two rings in a hard material like silicon carbide and a softer material like carbon respectively. The proper materials should chosen basing on liquid's chemical properties, pressure, and temperature. These two rings machined using a machining process called lapping in order to obtain the necessary degree of flatness, as one rotating with the shaft and the other being stationary. Then, there would be a number of secondary sealing surfaces require a fluid barrier but are not rotating relative to one another. And the actuation is provided to keep two primary sealing surfaces in intimate contact.
Since the mechanical seal is one of the particular seals in the industry, there exists more than one type of this term according to varied functional elements. Some common types are introduced in the following, It is generally classified into two main categories depending on whether the secondary seal to the shaft the dynamic or stationary. The dynamic one called pusher and the stationary one called non-pusher. Furthermore, there exists a common style called cartridge seal which is originally designed for installation in equipment where a component type seal was difficult due to the design of the equipment. For example, it is seen to design this type to fit pumps with varying stuffing box bore sizes and gland bolt patterns. What else, the gap seal is another type which is generally employed in bearings and other constructions highly susceptible to wear such as an O-ring.
Article Source: http://EzineArticles.com/4656883
A mechanical seal is simplified for an end face mechanical seal or a mechanical face seal. It is generally settled in rotating equipment, such as pumps and compressors. The mechanical seal is expected to prevent the liquid leak out of the pump between the rotating shaft and the stationary pump casting. In fact, with the competitive specifications, a mechanical seal does greater help than the mechanical packing which is widely used in the early times.
Generally speaking, a mechanical seal consist of four functional components: primary sealing surface, secondary sealing surfaces, a means of actuation and a means of drive. And the core part of the device is the primary sealing surface which combines two rings in a hard material like silicon carbide and a softer material like carbon respectively. The proper materials should chosen basing on liquid's chemical properties, pressure, and temperature. These two rings machined using a machining process called lapping in order to obtain the necessary degree of flatness, as one rotating with the shaft and the other being stationary. Then, there would be a number of secondary sealing surfaces require a fluid barrier but are not rotating relative to one another. And the actuation is provided to keep two primary sealing surfaces in intimate contact.
Since the mechanical seal is one of the particular seals in the industry, there exists more than one type of this term according to varied functional elements. Some common types are introduced in the following, It is generally classified into two main categories depending on whether the secondary seal to the shaft the dynamic or stationary. The dynamic one called pusher and the stationary one called non-pusher. Furthermore, there exists a common style called cartridge seal which is originally designed for installation in equipment where a component type seal was difficult due to the design of the equipment. For example, it is seen to design this type to fit pumps with varying stuffing box bore sizes and gland bolt patterns. What else, the gap seal is another type which is generally employed in bearings and other constructions highly susceptible to wear such as an O-ring.
Article Source: http://EzineArticles.com/4656883
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