There are lots of different types of valves for scuba tanks and the price of having a scuba tank serviced is based on the type of valve. I have been browsing eBay and other websites looking for scuba tanks to fill my PCP air rifle, lots of the tanks have valves that are needed for diving and therefore cost more to get serviced compared to non-diving style valves. I know you can change the valves but how do I find a 'Surface' valve, so I don't have to pay more to get it serviced. What are the 'surface' valves( that aren't used for diving) called. Sorry if the question is uninformed I'm a bit of a newbie.
Thanks