"Bob Pawley" <rjpawley@shaw.ca> writes:
> Instead I get two identical rows inserted containing the fluid_id = '3501'
> and 'Pump #1'.
Seems like the only way that's possible with the INSERT .. VALUES
formulation is if the trigger function gets executed twice. Maybe you
accidentally created two instances of the trigger? psql's \d on the
table should list the triggers for you.
regards, tom lane