The vent valve or air eliminator is the ...

• A. A simple vent cap
• B. A drain valve
• C. A safety relief valve
• D. Pump housing that allows air vapors to escape when opened

Answer: (D)

Air in the pump or fuel line must be released so fuel can flow without air locks. The vent valve or air eliminator is a component built into the pump housing that opens to vent air vapors as the pump is opened or primed. This venting lets any trapped air escape to the atmosphere, allowing the pump cavity to fill with fuel and continue delivering smoothly. It isn’t just a cap that covers an opening, nor a drain valve that removes liquid, nor a safety relief valve designed to relieve overpressure. Its job is specifically to vent air and vapors from the pump housing to keep the system primed and functioning.