How is oil pressure regulated in an aircraft engine?

How is oil pressure regulated in an aircraft engine?

• A. A pressure-relief valve senses the desired pressure and sends excess oil back into the engine sump.
• B. By varying the oil temperature.
• C. By restricting flow through a metering orifice.
• D. By adjusting the oil filter bypass.

Answer: (A)

Oil pressure is kept within safe limits by a pressure-relief valve on the oil pump. This valve senses the system pressure and opens when it reaches the preset value, sending excess oil back into the engine sump. By routing the extra oil away from the bearings and back to the sump, the valve maintains a relatively constant pressure across a range of engine speeds and oil temperatures. While oil temperature and viscosity can influence the actual pressure, they don’t actively regulate it the way a relief valve does. A metering orifice can affect flow, but without a mechanism to set a fixed pressure, it won’t hold pressure steady. The oil filter bypass mainly changes flow when the filter is clogged, not the normal pressure regulation.

Oil pressure is kept within safe limits by a pressure-relief valve on the oil pump. This valve senses the system pressure and opens when it reaches the preset value, sending excess oil back into the engine sump. By routing the extra oil away from the bearings and back to the sump, the valve maintains a relatively constant pressure across a range of engine speeds and oil temperatures. While oil temperature and viscosity can influence the actual pressure, they don’t actively regulate it the way a relief valve does. A metering orifice can affect flow, but without a mechanism to set a fixed pressure, it won’t hold pressure steady. The oil filter bypass mainly changes flow when the filter is clogged, not the normal pressure regulation.