MEP-803A whole house standby generator

[kaletheriot]

Does the fill neck cap have a vent in it? Doesn't seem to from what I can make out in the picture. Or... is there a vent located on the tank somewhere else?

Right there in the cap.

 

[Nutman]

Very nice setup, paint job is awesome and I like that I’m not the only one who vents tanks this way haha.

 

[Chainbreaker]

Right there in the cap.
View attachment 912379

Ahhh, much better view of that cap than the other smaller pictures where I looked but couldn't make out a vent hole.

The only other consideration that I ran across during "my local wet winter climate" was with today's formulation of ULSD diesel & its hygroscopic nature was my need to use a desiccant type of vent filter to trap moisture before it enters a 50-gallon tank mounted on genset trailer. I first experienced fuel degradation in my main tank with a slimy gummy substance coating fuel tank and rust at top of tank so I knew with storing 50 gallons it would be problematic.

I installed one of those desiccant filters that contains water moisture absorbing beads in it that are visible and turn purplish/black when beads reach saturation. Turns out if you can fabricate a bead holder type filter out of PVC pipe (YouTube hack) with a top that you can remove you can then recycle the beads by heating beads on sheet pan in oven to evaporate the moisture and reuse them again & again. Easy to maintain & eliminates expensive throw away bead filters.

Not sure if that is an issue in your location...however with 100 gallons of today's ULSD stored onboard with vent-breathing over time with any high humidity exposure it can eventually impact fuel quality if not consumed frequently even with the best fuel additives.

Edit: Here is just one example of mfg of commercially available desiccant type diesel tank moisture filter. Their Guardian series is recommended for diesel fuel applications. Or...You can fab up a DIY one using PVC pipe & commercially available silica beads incorporating some fine metal screen material & coffee filters if you're the creative type.