1.Packing seal :
Pipeline pump packing seal structure is simple, cheap, easy to repair, but the leakage of large, large loss of supply and consumption. Therefore, the packing seal is used for conveying the general medium, such as water, which is generally not suitable for oil and chemical medium, and can not be used in the precious, explosive and toxic medium.
2.Mechanical seal :
Mechanical seal (also known as end face seal) seal effect is good, little leakage, long life, but the price is expensive, processing and installation of maintenance is higher than the general requirements. The mechanical seal is suitable for transporting oil and chemical medium, and can be used for various kinds of medium with different viscosity, strong corrosion and granular medium. The American Petroleum Institute API610 (Eighth Edition) stipulates: in addition to the user specified, shall be equipped with container type mechanical seal.
3.Dynamic seal :
Dynamic seal can be divided into two types of back blade seal and sub impeller seal. The pump when the leaves back (or vice impeller) of the centrifugal effect to medium pressure seal Bu to atmospheric pressure or negative pressure, the pump does not leak during operation. When the centrifugal force disappears, the back blade (or the auxiliary impeller) is sealed, and the sealing device is sealed by the stopping and sealing device. The packing seal is used in the parking and sealing device which is matched with the back blade (or the auxiliary impeller). Packing seal with ordinary and mechanical elastic two. With the general packing seal pump similar to ordinary type packing seal, seal requirements at the micro positive pressure, in order to avoid packing friction. Mechanical elastic filler parking sealed by weight, the pipeline pump packing at run time to loosen, stop packing. In order to ensure the service life of the sealing device, the leakage rate of the pipeline pump is reduced, and the pump inlet pressure of the pump is limited by the dynamic seal.
