This standard specifies copper alloy pipe flanges (hereinafter referred to as flanges) with a nominal pressure of 5K for joining copper alloy pipes used for ship piping.
JIS F 7804:2000 history
2000JIS F 7804:2000 Shipbuilding -- 5K copper alloy pipe flanges for marine use
1996JIS F 7804:1996 Shipbuilding -- Silver brazing 5K pipe flanges