The stationary part of the seal is fixed in the pump housing. It consists of a stationary seat and a stationary secondary seal.
The stationary part of the seal is fixed in the pump housing. It consists of a stationary seat and a stationary secondary seal. The secondary seal prevents leakage between the stationary seat and pump housing. It prevents the seat from rotating in the pump housing as well.
The pumped liquid (A) is generally in contact with the outer edge of the rotating seal ring (B). When the shaft starts to rotate, the pressure difference between the liquid (A) in the pump housing and the atmosphere (D) forces the liquid to enter the sealing gap (from B to C) between the two flat rotating surfaces. A lubricating film is generated.
The pressure in the sealing gap is reduced from B to C, reaching the pressure at D. Leakage from the seal will appear at out in the air.
The parts of the seal inside the pump are subjected to a force emanating from the pressure within the pump. The axial composant of this force, together with the spring force creates the closing force of the seal.