Customized Steam Turbine HP Main Stop Valve Bushing
During the maintenance and operation of the steam turbine high-pressure main stop valve, the valve stem bushing is a critical precision component that is easily overlooked yet vitally important. Operating continuously under harsh conditions of high temperature, high pressure and frequent opening/closing cycles, the bushing's guiding accuracy and sealing performance directly determine the operational stability of the valve stem, the tightness of valve sealing and the safety of the unit. It serves as an essential basic part to ensure reliable operation of the high-pressure main stop valve.
Core Functions
The high-pressure main stop valve bushing performs two core functions:
- Precise Guiding: Restricts the movement path of the valve stem to ensure accurate centering of the valve stem and valve disc, preventing deflection, shaking, jamming and abnormal wear during opening and closing operations
- Auxiliary Leakage Control: The precision fit clearance between the bushing and valve stem effectively controls stem steam leakage, with excess leaked steam delivered to the deaerator and gland steam condenser via dedicated pipelines
Equipment Hazards from Abnormal Fit Clearance
The precision of the bushing fit clearance is a key control indicator in maintenance work:
- Excessive Clearance: Aggravates valve stem shaking and leads to guiding failure, resulting in poor contact between valve disc and valve seat with sharp rise in stem steam leakage
- Insufficient Clearance: Increases friction resistance of the valve stem, causing valve jamming and opening/closing delay, potentially compromising unit emergency shutdown reliability
Additional defects such as inner wall wear, surface scoring and deformation of the bushing will undermine valve operating stability and shorten equipment service life.
Additional Support Components: Besides high-pressure main stop valve bushings, our company supplies a full range of supporting parts for unit maintenance, including:
HP governor valve oil actuator, front bearing box steam baffle, front shaft seal gland plate screws, valve stems made of 2Cr12NiMo1W1V, high-temperature thick washers, high-temperature hexagon head screws, steam valve connectors, slotted nuts of 10Cr11Co3W3NiMoVNbNB, acrylic covers for intermediate bearing box, flanges of 14Cr11MoV, and support rollers for high & intermediate pressure rotors.
