We, jingjiang top far international trading co., ltd(www dot chinatopfar dot com), can supply marine air vent head(air pipe head) and sounding head as below: Air pipe head(Air Vent Head): Standard:GB2506-89, C/T 3594-94, ISO2084-1974, JIS Nominal Dia:DN50-DN550A Connection method: Flange Material: Cast iron, stainless steel Type: Type A, B,D,E,FS A: Cap type air pipe head B: Gooseneck type air pipe head D/E: Float type air pipe head FS: Floating ball type air pipe head, CB/T 3594-94 Stainless steel air pipe head Sounding head: Standard:CB/T3778-99 Type: Type A, C Nominal Dia:DN40-DN150A Connection method: Welding Material: Cast iron, stainless steel,Copper