If that label behind the regulator is the same as this one from a 1994 Manchester horizontal....
(click to enlarge)
LPTankSticker1994.jpg
.... you'll want to have it filled horizontally per manufacturer instructions.
If your tank is the original, it was made before OPD (overfill protection device) valves were required in horizontal tanks (according to the last post in
this RV.net thread). You may want to do further research to confirm. A call to a local propane shop that does tank re-certifications might be helpful if you can talk to a tech and not just a scheduling clerk. (You'll also want to talk to him/her about re-certifying your tank if it's out of date according to the date code stamped into it and hasn't been re-certified to bring it current).
We can't see the handwheel (valve handle) in your photo but it would be round if you don't have an OPD or triangular if you do.
The thing that confuses me about this is whether you may or may not have difficulty getting a fill. I believe some places may refuse when they don't see the OPD triangular handwheel but I'm not sure that happens enough to be a real issue for someone with a pre-OPD tank.
Also- I'd pull the tank to fill as I'd want my rig well away from the fill area in case
something goes wrong. But as you see in that RV.net post, the guy says the attendants often fill his vertically despite what the label says. This appears to be another of those situations where you need to do enough research to feel comfortable you know what you have and how you want it filled.
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