mike_s
Contributor
I think you're going to have a hard time finding a 300 bar DIN-Yoke convertor. most are going to be 20o bar or something like 230bar. The reason you won't find a 300 bar one is that most yoke valves aren't rated for 300 bar (or is the yoke that goes around the valve) and they don't want people using yoke on tanks that are that high pressure. (which is the reason people use DIN on those higher pressure tanks).
If you'll notice at that URL you posted about the insert, it says will only work with 200bar valves. It might "fit" in a 300bar valve, but you're exceeding the working pressure of yoke at that time and asking for a high pressure headache in the back of the head if it stress fractures while you are wearing your gear.
as for going for rental tanks on vacation, chances are that your rental tanks (in the US) are Alum 80's at 3000psi, which the 200 or 233 bar convertor will do fine on.
If you'll notice at that URL you posted about the insert, it says will only work with 200bar valves. It might "fit" in a 300bar valve, but you're exceeding the working pressure of yoke at that time and asking for a high pressure headache in the back of the head if it stress fractures while you are wearing your gear.
as for going for rental tanks on vacation, chances are that your rental tanks (in the US) are Alum 80's at 3000psi, which the 200 or 233 bar convertor will do fine on.