Research of serviceability of pulsed face seals with pumpback structures

The article discusses characteristics of pulsed face seals, analyzes their work process, and investigates the parameters of seal working efficiency. The experience of investigating seals by leading companies and institutions is presented. Experimental studies on the measurement of water leaks and the frictional torque at variouspressure differentials, rotor speed and spring rates have been conducted. Computational research for the case of air used as the seal working fluid has also been carried out. The dependences of the frictional moment on the rotor speed for seals with different mutual arrangement of pumpback structures have been compared on the basis of the experimental data provided by Stuttgart university. The change of pressure in a pumpback structure is analyzed for the following cases: remote structures, coincidence of structures, proximity of structures. A series of tests has been carried out to estimate the reliability of a pulsed seal. The test results are used for the investigation of experimental frictional torque dependences at different rotation speeds, pressure differentials and spring rates. It has been established that the optimum value of the spring rate is a prerequisite for ensuring the required sealing characteristics.