The shaft seal is a sealing device that prevents leakage at the pump shaft and the housing. Commonly used shaft seal types include packing seals, dynamic seals, and mechanical seals.
The packing sealing structure is simple, the price is announced, and the maintenance is convenient, but the leakage amount is large and the power consumption loss is large. Therefore, the packing seal is used to transport general media such as water; it is generally not suitable for petroleum and chemical media.
The dynamic sealing performance is reliable, the price is cheap, and the maintenance is convenient. It is suitable for conveying medium containing more solid particles. The disadvantage is that the power loss is larger than that of the machine maple, and the life of the parking seal is short.
The mechanical seal has reliable performance, small leakage, long service life, low power consumption, low maintenance rate, small wear on the shaft (sleeve), wide temperature, pressure and pump speed range, and meets various corrosive media. Sealing requirements for harsh working conditions such as solid particle media, and with the development of the domestic mechanical seal industry, whether it is a domestic pump or an imported pump, the mechanical seal can be realized domestically.
It has obvious cost-effective advantages, so the machine maple seal becomes the most common form of seal.
Since there is no external flushing liquid in the crude oil tank project, and the medium viscosity of the crude oil is large, the crude oil transfer pump needs to adopt a balanced single-end mechanical seal that does not require an external flushing system. The viscosity of the crude oil medium is large, and the friction pair of the mechanical seal is tungsten carbide to silicon carbide. The friction pair has good wear resistance and can maximize the service life of the seal. The application of common materials for O-rings for static sealing, the O-rings are made of fluoro rubber.
