Conn Sousaphone recognition guide

Here is a little table I made to help me identify Conn sousaphones based on the bell and valve configuration. I think I have most models in there. This table does include bell up model sousaphones, but not helicons. This table does not list high pitch models.

Conn sousaphone recognition guide
Bell diameter (inches) 3 valves 4 valves
20" 18K 20K
22" 34K 36K
(1920's, check
your serial number)
26K (Eb) 28K (Eb)
(1920's, check
your serial number)
38K, 42K 40K, 44K
24" 14K, 21K, 26K (Eb), 32K -
24" Fiberglass 36K -
26" 10K, 20K, 38K -
26" Fiberglass 22K -
28" 46K 48K