can you tell me a manufacture of model boiler gas tanks that does not use the Ronson type filler's ?,
Of course not but it's easy to see why isn't it? If they fitted a proper valve it would never be the right thread or pipe size to suit everyone and, probably the biggest factor, they are cheap. However just because that's what a manufacturer gives you doesn't mean to say that is what you have to accept. With a Ronson type of valve you have absolutely no idea how much liquid you have put in the tank, unless you are in the habit of carrying around a set of scales in your pocket. This at the least can be inconvenient when the tank runs out before you thought it should or it can be hazardous when the tank is actually completely full because another severe deficiency is the fact that the valve does guarrantee you a maximum liquid level so you could even find that you do not have any free gas space left at the top after filing.
I prefer to know a little bit more about what is going on. When I've filled my tank I know exactly what level of liquid there is in there and I know that there is a gas space above the liquid. As I fill the vent valve is only just off it's seat so I'm loosing a minimal amout of gas and as soon as I see liquid I stop. It is simple and quite safe.
I'm not going to knock anyone who still prefers to use the Ronson type of filler, if they want to go for a walk in the woods and try to gas half the local squirrel population and waste as much gas as they manage to get into the tank they are a very effective device.
As always it's each to thier own and the important thing is that no matter what method you use you should be aware of the nature and dangers of gas and treat it accordingly. An example of this is that after each fill I blow the hull thriough with a small battery driven fan. This is only a precaution and I'm sure quite unecessary but you can't be too carefull. Before anyone says anything no, it isn't an intrinsically safe fan, I operate it from outside the hull!! I'm sure that sticking your head in there and blowing would be just as effective as well.