Watson-Marlow DuCoNite 25 - Manual (Page 47)

MAINTENANCE
47
7.10.2 Drain connection
Drain piping can be connected with an optional part (A)
fitted at the breather. This is a 1" NPT threaded
connection.
CAUTION
The drain piping must be connected to an
open reservoir, to prevent pressure built up
inside the pump housing.