I’d like to ask gently about the mechanical seal of the pump

The black component called \"Silicon Carbide\" is the rotating ring of the mechanical seal

The component with a set screw on the sleeve is the moving ring; the moving ring generally consists of: the moving ring itself (the sealing surface), a moving ring seal (an O-ring or 4F gasket), a spring, a set screw, and a moving ring seat. Working principle of mechanical seals: It relies on elastic components (such as springs or bellows, or a combination of bellows and springs) together with the pressure of the sealing medium to generate an appropriate compressive force on the contact surfaces (end faces) of the rotating moving ring and the stationary ring. This forces these two end faces to fit tightly together, with an extremely thin layer of liquid maintaining between them, thereby achieving sealing. This liquid film possesses dynamic pressure and static pressure, serving to lubricate and balance pressures. When the rotation axis turns, the moving ring is rotated by means of set screws (thrust screws) and springs. The anti-rotation pin is fixed to the stationary gland to prevent the static ring from rotating. When the sealing end face wears out, the moving ring, together with its sealing ring, moves slightly axially under the force of the spring, thereby achieving a certain degree of compensation; hence it is called a compensating ring. The stationary ring does not have compensatory capability, which is why it is called a non-compensating ring. Through different structural designs, the compensation ring can be borne by the moving ring or by the stationary ring. A component composed of a compensation ring, elastic elements, and secondary seals is called a compensation ring assembly.

This is the sleeve and moving ring assembly; the black carbon ring located in the spring box is called the moving ring.

Does anyone know how to adjust the spring seat distance, and what are the effects of tightening it?

The spring seat you mentioned is also known as the moving ring seat, and changes in its position can affect the compression amount of the mechanical seal. If it is tightened, the compression amount of the mechanical seal increases, which in turn increases the load on the pump; the forces acting on the moving and stationary sealing surfaces also increase. Excessive tightness may cause friction and heat generation at the sealing surfaces, leading to damage to the mechanical seal. If it is loosened, the compression amount of the mechanical seal decreases, and the forces on the moving and stationary sealing surfaces are reduced, which may result in leakage from the mechanical seal. Therefore, during the installation of a mechanical seal, in addition to requirements regarding the roundness, roughness, and shaft runout of the pump shaft, attention must also be paid to the parallelism and roughness of the sealing surfaces, as well as the adjustment of the compression amount. For a more in-depth understanding of mechanical seals, I recommend referring to JBT 1472-2011 \"Mechanical Seals for Pumps\", which provides detailed information on this topic*

This is the bushing plus the moving ring. I suggest you look up some information on mechanical seals to study!