Pipe dia to anti siphon valve 38 ocean cc

[Jam]

Hi
At wend notice some sea water in engine compartment, about 1/4 bucket.  Think it may be from Volvo anti siphone device as end of pipe slightly wet. Would like to replace with vetus one.  Can anyone tell me the pipe dia that's there, boat in 38 ocean cc as vetus accept only certain dia pipe.
Cheers
John

[Symphony]

If it is leaking it probably needs cleaning. If you do replace it with a Vetus , they all have stepped spigots 13,19,25,32mm dia and you cut off to the right size. Think yours will be 19mm