That looks like the fuel filter/water separator that was on my 6.0 van. The plastic piece with the nipple is so you can drain any water out. If I remember, when you get a replacement filter it should come with a new o ring, at least the OEM filter did. Definitely recommend you stick w Ford OEM filter. The other filter is in the engine bay.
Yes O ring. (And that’s a 6.0 diesel) How long have you had the van, as you should be replacing that filter quite regularly, (and it comes with new O ring). for the O ring to go, probably means you haven’t been keeping up with changing it. I change that one every 10k and the one in the engine bay every 15 to 20k.
That looks like the fuel filter/water separator that was on my 6.0 van. The plastic piece with the nipple is so you can drain any water out. If I remember, when you get a replacement filter it should come with a new o ring, at least the OEM filter did. Definitely recommend you stick w Ford OEM filter. The other filter is in the engine bay.