Which component acts as the first stage of filtration?

• A. Air eliminator
• B. Water drain valve
• C. Filter element
• D. Go-no-go fuse

Answer: (C)

The first stage of filtration is the filter element, because it is the actual filtering media that the liquid passes through to remove contaminants. As fuel flows into the filter housing, it moves through the porous material of the element, which traps dirt, rust, and other particulates. This initial barrier cleans the fluid before it proceeds to the rest of the system.

Other components serve related but different roles: the air eliminator releases trapped air to prevent air pockets, the water drain valve removes water collected in the system, and the go-no-go fuse is a safety/check device rather than part of the filtration process.