question: Racor filter fittings

[seattleboatguy]

I've noticed that all my Racor fuel filters have 2 ports near the bottom of the sediment bowl. I understand the lowest fitting; to drain off the worst of the sediment. Why is there a second fitting a few inches above the lower fitting, and why does this second fitting have an o-ring, while the fitting at the very bottom has no o-ring?

 

[psneeld]

the higher fitting is for an optional water sensor.


Why yes and no O rings...not sure.

 

[Steve]

Is the bottom one pipe thread? if so will not use an Oring