The fan servo valve gasket TY9112 is a core sealing spare part for the electro-hydraulic servo actuators of power plant induced draft fans and primary air fans. Installed at the mating surface between the servo valve and the actuator cylinder, it undertakes the critical functions of hydraulic oil sealing and pressure isolation. It prevents external leakage of high-pressure fire-resistant oil in the fan servo control circuit and stabilizes the pressure at servo valve ports, serving as a fundamental component for the fan regulation system to respond precisely to control commands. In the electro-hydraulic regulation system of boiler fans, the servo valve drives the cylinder with high-pressure fire-resistant oil to continuously adjust the opening of fan dampers and moving blades. The entire system operates under severe working conditions including alternating high oil pressure, continuous equipment vibration and fluctuating oil temperature. The TY9112 gasket acts as a key part to resist medium leakage and isolate pressure among oil chambers. Once the gasket suffers aging, cracking or loss of compression resilience, fire-resistant oil leakage and system pressure drop will occur directly, resulting in servo valve control drift and jamming of moving blade adjustment. In severe cases, fan regulation failure may be triggered, threatening the safe and stable operation of the boiler unit.
The material of TY9112 gasket features outstanding resistance to corrosion by phosphate ester fire-resistant oil, matching the medium characteristics of power plant EH oil systems. Its temperature resistance range covers the normal operating temperature range of fan servo systems, resisting material hardening and plastic deformation caused by oil temperature fluctuation. It has a low permanent compression set. Under long-term bolt compression and alternating oil pressure, it can maintain stable sealing compression force, adapt well to alternating stress generated by continuous vibration of the fan body, and is less prone to elastic attenuation and sealing surface failure.
This gasket is applicable to thermal power servo actuators and is a mandatory consumable during unit overhaul, servo valve disassembly and inspection, as well as cylinder disassembly and maintenance. During maintenance operations, a brand-new TY9112 gasket must be replaced when disassembling and assembling the servo valve, and reused old gaskets are prohibited. Before installation, thoroughly clean the mating surfaces of the servo valve and cylinder to remove residual old gasket debris and oil sludge impurities, so as to prevent hard particles from scratching the sealing surfaces and causing indentation-induced leakage. During assembly, fasten bolts evenly in a diagonal sequence to avoid local crushing of the gasket due to uneven stress. In daily inspections, focus on checking whether there are traces of fire-resistant oil seepage at the servo valve mating surface, predict the risk of gasket aging and failure in advance, and prevent leakage faults from worsening.
As a consumable sealing component of the power station fan electro-hydraulic regulation system, the fan servo valve gasket TY9112 has a simple structure yet directly determines the operational reliability of the whole servo regulation mechanism. Fan servo systems impose extremely high requirements on oil cleanliness and sealing performance. Stable operation of the gasket ensures accurate transmission of servo valve pressure and flow signals, guarantees sensitive response of fan moving blade adjustment, and avoids unit load reduction and unplanned shutdown risks caused by sealing failure. It is an indispensable spare part included in the maintenance list of boiler auxiliary equipment in thermal power plants.
DFYLSYC-2026-09-11-A
