I use propane at my home, so I've had a fill line installed to fill smaller tanks from my larger 1000 gal. tank.
When filling the smaller 20 gal. grill tanks, I simply hook up the fill line, open the valves on the tanks (big and little) and open the fill line valve. Once flowing, I use a small screw driver to open the set screw vent on the small tanks valve. This vents off gas while the tank is filled with liquid. Works well, even while it seems wasteful and is rather odiferous.
Recently, I picked up an older 100 Gal. propane tank to use on my gas forge because the little grill tanks where freezing up. I converted an old 2 wheeled dolly I picked up off Craigslist to transport the 100 gal. tank between my home tank and the shop and got them both painted up nice. While preparing to fill the new tank, I noticed that there is no vent on the valve. I looked at new 100 gal. tanks at Menards, same fittings etc. (no OPD), but they have a thumbscrew type vent.
Is this an issue? Do I just fill the tank without venting? Is there another way? Do any of you have experience with this?
BTW, the cap shown in the pic is from an O/A cylinder. It's just sitting there to keep the snow and ice (coming soon) off of the valve.
I'm going to go by my dealer when I get some time to get some answers. Any help in advance would be greatly appreciated.
-Derek