G'day Guy's,
With that Swan Keg I didn't find any threads on removing the spear so as I worked out how to remove it I took a few pic's and there is a trap or two to be aware of.
The Swan Keg, First use a pipe wrench etc to unscrew the cap and it will rise about 10mm at the most.
next there is a rubber keeper that needs to be removed and I found a couple of screwdrivers did the job nicley
Once the rubber keeper is removed one will find a SS retaining washer and a spring
Carefully remove that SS retaining washer using a couple of screw drivers AND BE AWARE once that said retaining washer is free it head for the moon taking your nose with it if it is in the way....
Now simply remove the spring and the spear and the job is done.
Now the flange measures 69mm OD so I do think a 3" tri clamp should fit so no other mod's should be needed to use a Swan Keg for a boiler
Cheers Bryan