What effect do clogged fuel oil strainers have on suction readings?

When fuel oil strainers become clogged, they create a restriction in the flow of fuel oil. This restriction leads to an increase in the resistance that the fuel pump must overcome to draw fuel through the system. As the pump works harder to maintain fuel flow, the negative pressure created in the suction line rises, resulting in high suction readings.

In a properly functioning system, suction readings are typically indicative of the fuel oil being drawn into the pump. When strainers are clogged, the pump's inability to draw the required amount of fuel leads to an increase in suction pressure, which can ultimately affect the pump's efficiency and operation. Thus, monitoring suction readings can provide crucial data for identifying issues like clogged strainers that may need attention.