I carry an ASME built-in tank and occasionally carry DOT tanks. Since your readership here covers a variety of custom built vans and home built (non-RVIA rated) class B equivalents that carry DOT tanks, as well those that pull trailers or have other RVs, this concern is germane in the broader context.
My ASME tank looks in the same condition as the pictures posted, so I'm looking to see what requirements my tank requires. It seems very, very odd that there are so many DOT requirements, yet ASME tanks lack the same oversight. And the risk is that RV tanks are largely hidden under the frame and hence, they get less attention.
What I found covering ASME tank requirements was very little. This 2107 reference from the Propane Research and Education Council on 'Cylinder Recertification' covers mostly DOT tanks, but it also has an answer on page 135 to the OPs question as to what labels are required on ASME tanks:
https://www.cfins.com/wp-content/themes/cf/pdf/CylinderRequalificationStudentManual.pdf
CONTAINER MARKER REQUIREMENTS
Type of container: ASME tank
Application: RV or Motorhome
Openings required to be marked: All except relief valve and liquid level gauges.
Ebay has some labels, but they don't cover all the requirements and some look like they are possibly used to fake tanks past inspections. I wouldn't want to be caught with an improperly labeled tank. In Colorado, they wouldn't allow any RV to go over a dam, even my little 3/4 ton Dodge. (But 1 ton work trucks pass by without question. Your post 9/11 tax dollars at work).
So anyone, if you have any good references for ASME tank requirements, or have experience in refurbishing or replacing tanks, please post them.
Or should this be a separate thread?