Interesting comments about the valves being soldered in in Spain and not being able to buy used ones. Here I just got one of those big next to house ones from the scrap yard for a dozen beer, the 9 kg ones are about $5 scrap value. Cylinders can be rented /leased or bought outright but buying means you pay for a cylinder test every 10 years. A 32 mm 3/4" drive impact socket with a bit cut out of the side whizzes the valve out real fast.