Nomenclature of brazing and welding bushes

Example of the nomenclature of brazing and welding bushes:

S|42,2|1 5/8|57|49

Basic material of the bushing
S: steel
Ms: brass

S|42,2|1 5/8|57|49

Diameter B in mm (see sketch below)

S|42,2|1 5/8|57|49

suitable for brazing pipes with pipe diameter in inch ('') according to DIN EN 12735

S|42,2|1 5/8|57|49

Diameter D in mm (see sketch below)

S|42,2|1 5/8|57|49

Diameter A in mm (see sketch below)

Examplary sketch of a brazing and welding bush (applies similarly to other brazing and welding connections), showing the dimensions that are relevant for connection to the compressors, pressure vessels and piping:
A: Outside diameter at pipe insertion end
B: Inside diameter at pipe insertion end
C: Pipe stop diameter, stepped
D: Largest diameter at sealing surface, connection diameter e.g. to compressor, pressure vessel or valve
Sketch of the bushing in the above example