I'd guess a check valve too, if the flow is from the bottom of the picture. That is one very funky set up, using hose clamps on a fuel line; and injury on insult using those cheap perforated clamps. Methinks that is not OEM....
The cheap clamps is a good point. This is a 330 Cummins on a Nordic Tug. Maybe a previous owner modification?
Yep, airsep drain check valve. Nothing to do with fuel.
I will double check my hose trace. My fuel lines are blue so I just assumed that was what I was looking at.
. . . . . That is one very funky set up, using hose clamps on a fuel line . . . .
What's wrong in using hose-clamps on hose carrying diesel fuel? I can see lots of problems in NOT using them!
Yep, airsep drain check valve. Nothing to do with fuel.