Kubota KX080-3 Workshop Manual page 402

WSM KX080-3 Mechanism
(3) When the pilot pressure rises higher, the poppet spring chamber (i) gets connected to the A-port side
with the spool internal passage in between. The poppet s orifice (j) then causes a pressure difference
between B-port and poppet spring chamber, which gets the poppet open.
(h)
Fig. 4 With oil flowing from B-pot to A-port (at high pilot pressure)
(e)
IV-M-118
IV Hydraulic System
(i)
(j)
B port
(m)
A port
(e) Pilot chamber
(h) Control
(i) Poppet spring chamber
(e) Pilot chamber
(i) Poppet spring chamber
(j) Orifice
(l)From boom cylinder bottom
(m) To main control valve
(l)