Installation and use of mechanical seals for pumps

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来源:    日期:2015-7-27    浏览次数720次

 Mechanical seals are widely used in various types of pumps. Mechanical seal is a kind of sealing device with high precision, and it has certain requirements for the installation and use of the condition.

1, the general principle of mechanical seal installation
(1) understand the equipment, to understand equipment shaft speed, shaft diameter; accuracy of equipment manufacture and sealing cavity size, equipment service life and equipment status in the production process, to make the comprehensive and balanced consideration.
(2) estimation of media pressure. Pump seal chamber pressure is generally not the pump's outlet pressure, but less than the pump pressure. (3) to ascertain the sealing medium. To understand the status of the sealed medium, a gas or a liquid, medium containing particles and particles of; understanding dielectric property, temperature, so that the rational selection and take necessary cooling and flushing, lubrication measures.
2. Technical requirements for mechanical seal installation
(1) the radial runout tolerance mechanical sealing parts of the shaft or sleeve: diameter of 10~50mm is greater than 0.04mm, 50~120mm, 0.06mm. The surface roughness of the shaft or sleeve should meet the technical requirements, size tolerance is h6. (2) the axial direction of the drive shaft is not more than 0.2mm.
(3) seal end surface of the cavity on the surface of the shaft runout tolerance: shaft or sleeve diameter runout tolerance: diameter of 10~50mm, 0.04mm, larger than the diameter of 50~120mm, 0.06mm
(4) end of the shaft or sleeve and seal cavity to chamfer. The shaft diameter of more than Phi 30mm of 3 x 10 degrees, shaft diameter > Phi 30mm of 4 x 10 degrees.
(5) when the transmission medium temperature is too high, too low or containing impurities particles, flammable, explosive, toxic, should take the corresponding resistance, flushing, cooling, filtering and other measures.
(6) for some by drive spring mechanical seal must pay attention to spring rotation to that shaft rotation direction should make the spring more and more tight, otherwise it will cause seal failure, spring rotating to the selection by the following method determine: by static ring to ring at shaft clockwise rotation with dextral spring, on the other hand, the selection of left-handed spring.