Yes, 3 fittings;
#1 Purge Valve on intake
#2; Fuel tank vapor line goes into a roll-over valve to get tank fumes.
#3; With 99, This hose goes to the "Tank Solenoid" and has vacuum sensor on fuel pumps' top.
The solenoid is normal de-energized, open all day. Using PWM, the Purge will open when PCM see's the correct conditions as this adds gas fumes into the engine. It watches the #1 02 sensor(s) to stay within fuel trim.
Being open all of the time is where problems happen as it must close & seal during EVAP testing. The air has dirt & dust in it and is pulled into this solenoid all of the time as you drive.
You'll have EVAP software, so warm, at highway speeds and based upon a PCMs' internal clock, the "Tank Vapor" solenoid will close. To "Test" the EVAP's integrity, the purge is opened while the tank solenoid is forced to close. This allows vacuum measured at inches of water. As the vacuum drops and hits 8 in h2o, the purge is closed, with the tank solenoid remains closed...so seal fuel tank, canister, hoses, gas cap and fuel tank solenoid. Over two minutes, the PCM watches the vacuum sensor at the fuel pump. If it looses vacuum to reach 12 in h20 or more, then that's a small leak. The poor fuel tank solenoid is "Normally" mount under the bed, behind the rear wheel and may not seal because of the dirt & dust. These usually are not cleaned, just replaced. This is called the "Enable Criteria" for running the EVAP check, but the tactics behind it.
Sound like you're fine... It just how it works, because the canistor capture fumes when re-fueling, and sloshing around and when the tank is between 80% - 20% is when the EVAP test run. So, if the sender is inop, it will set a code and abort the test...but your gauge will be wonky as well.