Had a word with Nigel from Pendle Steam and described my requirements to heat (as quietly as possible) my horizontal water tube boiler which measures 9 in long, 5 1/2 in diameter with a 2 1/4 inch flue, fitted with 8 cross water tubes.
This is an old design from the 50's and he suggested none of the burners would be able to supply the brut force heat that the original blowlamp burner would supply as my boiler is of an inefficient type!
Oh well, back to playing with Sievert and weed burners!
Alan