Heidolph ROTAVAC 20 - Manual (Page 26)

Documents are only to be used and distributed completely and unchanged. It is strictly the users´ responsibility to check carefully
the validity of this document with respect to his product. Manual-no.: 01-005-005-36-1
page 26 of 35 Translation of the original instructions
6.3 Replacing the valves
EX
IN
Loosen the clamping brackets on the valve heads.
➨
Unscrew at each clamping bracket the two countersunk
screws with a Torx driver T20. Remove the clamping
brackets.
Loosen connection fastener slightly.
➨
Turn the fillister head screw with a Torx driver T20 at most
one turn.
+ Do not detach the fillister head screw from the square
nut.
➨ Open the hinged cover of the connection fastener with a
slotted screwdriver.
➨ Remove valve heads along with the disc springs, con-
nection tube if applicable, hose nozzles and connection
fasteners or move the valve heads carefully aside. Note
position and orientation of the valve heads.
+ Note position and alignment of valves.
➨
Check valves and O-rings for damage and soiling.
➨ Replace valves or O-rings if necessary.
➨ Use petroleum ether or other industrial solvent to remove
deposits. Do not inhale vapors.
➨ Insert O-rings and valves. See figure for the correct posi-
tion of the valves:
+ Inlet side (IN):
Marked ”IN” next to the valve seat. The valve tongue points
at the kidney-shaped orifice in the valve seat.
+ Outlet side (EX):
Marked with ”EX” next to the valve seat. The valve is ori-
ented the same direction as the valve at the inlet side.