The generator sealing oil system is a key component to ensure the safe and efficient operation of the generator. Among them, the float valve SFDN80 plays an important role in maintaining the stability of the oil level in the oil tank. This article will introduce in detail how the SFDN80 float valve automatically adjusts the oil level according to the change of the liquid level, and the key role of the sealing ring in this process.

The float valve SFDN80 is exquisitely designed. Its core component is a float floating on the oil surface. This float is connected to the valve disc in the valve body through a connecting rod. When the oil level in the sealing oil tank changes, the float will float up and down accordingly. Specifically, when the oil level rises, the buoyancy of the float increases, driving the connecting rod to push the valve disc upward, and the valve opening degree decreases, thereby slowing down or stopping the oil supply to prevent the oil tank from overflowing; on the contrary, when the oil level drops, the buoyancy of the float decreases, the connecting rod pulls the valve disc downward, and the valve opening increases, allowing more sealing oil to enter the oil tank until the oil level returns to the set range.

This simple and effective mechanical feedback mechanism can achieve precise automatic control of the oil level in the oil tank without external power supply or complex control system, ensuring the stable operation of the sealing oil system and effectively avoiding the problem of generator seal failure caused by abnormal oil level.

In the SFDN80 float valve, the sealing ring plays an indispensable role. It is a key component to ensure the sealing performance of the valve. The sealing ring is made of oil-resistant, heat-resistant and wear-resistant rubber material. It is installed between the valve disc and the valve seat. When the valve is closed, it fills the gap between the two through its own elasticity and shape to prevent oil leakage.

The performance of the sealing ring directly affects the sealing effect and service life of the float valve. Although the sealing ring has good chemical stability, low friction coefficient and wide temperature adaptability, it is necessary to ensure that the sealing ring can maintain good sealing under various working conditions in the high temperature and harsh environment of the power plant. Regular inspection and timely replacement of the sealing ring are essential to maintain the normal operation of the float valve and even the entire sealing oil system.


Yoyik offers various types of valves and pumps and its spare parts for power plants:

Welding type corrugated pipe globe valve KHWJ15F 1.6P
Motor YZPE-160M2-4
SOLENOID:SMC VQ5100-4
float shut off valve PY-40
centrifugal pump in water treatment CZ50-250
hydraulic oil splitter (servo valve) D634-319C
inline shut off valve KHWJ10F1.6P DN10 PN16
Hydrogen system shut-off valve WJ50F1.6P-II
1.5 mm – DN200 dome valve seal P5462E-00
types of servo valve S63JOGA4VPL
bladder 20 ltr, 197 mm dia, 900 mm length, fitting port size 30 mm, NBR
high pressure servo valve J761-003A
O type Seal ring 280×7.0
EH main oil pump oil seal PVH098R01AD30A250000002001AB010A
Relief valve YF-B10H2-S
BLADDER NXQ-A-10/20 F Y
Screw Pump HSNH 210-36
LIMIT SWITCH RPH-02
main sealing oil pump coupling cushion ACG070K7NVBP
sealing oil screw pump HSND280-46N