Im looking into buying a rapid recovery cylinder for my old gravity HW system. Im having a few problems identifying standard connection heights.
All the ones i have found say that for the 117 litre cylinder, the lower coil connection is 100mm from the base and the top coil connection is 400mm. The cylinder i have at the moment is a 23 year old "crown brand" and although the top connection measures in at 400mm from base to centre of the connection, the lower one seems to be 95mm to centre, not 100.
Has the 100 and 400mm always been a standard height for the coil tappings?
All the ones i have found say that for the 117 litre cylinder, the lower coil connection is 100mm from the base and the top coil connection is 400mm. The cylinder i have at the moment is a 23 year old "crown brand" and although the top connection measures in at 400mm from base to centre of the connection, the lower one seems to be 95mm to centre, not 100.
Has the 100 and 400mm always been a standard height for the coil tappings?