Burkert 2301 Series, Operating Instructions Manual, Page: 11 / 48

11
Structure and function
Control function B (CFB)
Opened by spring force in rest position
Control function I (CFI)
Actuating function via reciprocal
pressurisation.
6.2.2 Flow direction below seat
Depending on the variant, the valve is closed against the medium
flow either with spring force (CFA) or pilot pressure (CFB or CFI).
Because the medium pressure is below the control cone, it helps
open the valve.
WARNING!
Valve seat leak if there is too little minimum pilot pressure or
high medium pressure.
Minimum pilot pressure for CFB and CFI that is too low, or
failing to meet the permitted medium pressure, can cause a
leak in the valve seat.
▶
Adhere to minimum pilot pressure.
▶
Do not exceed the medium pressure.
▶
See chapter “7.4.4 Pressure ranges” .
Flow direction
1 2
Marking on the
housing
Rest
position
CFA
Rest
position
CFB/CFI
Fig.2: Flowdirectionbelowseat(closingagainstmedium)
Type 2301
English