To ensure main propulsion turbine bearings are receiving proper lube oil supply, you should check the?

Checking the sight flow glass in the bearing oil supply line is essential for ensuring that main propulsion turbine bearings receive a proper lubrication oil supply. The sight flow glass allows personnel to visually confirm that oil is flowing to the bearing. This visual indicator is critical because it provides immediate evidence of oil supply continuity, which is vital for maintaining lubrication and preventing damage to the bearings. If oil is not flowing as intended, it can lead to overheating, wear, and potential failure of the bearings.

While other factors such as oil viscosity, temperature, and pressure are also important for the overall health of the lubrication system, they do not directly indicate the immediate supply of lubricant to the bearings. For example, oil viscosity affects the oil's functional performance, but does not provide a direct visual cue of flow. Similarly, the temperature of the oil filter could indicate overall system efficiency but does not directly inform you about oil flow to the bearings. The pressure gauge might show sufficient pressure within the system, but it doesn't confirm that oil is reaching the bearings themselves. Thus, the sight flow glass serves as the most direct and effective means to ensure proper lubrication to the turbine bearings.