Agilent Technologies 6850 Series II User Information page 112

4.
Figure 18. The adjustment set screw
5.
6.
7.
8.
9.
10. Reassemble the valve box.
Replacing a valve rotor
There are two types of rotors (see
valves. Rotor type can be identified by color:
•
•
Released: March 2004
Loosen the adjustment set screw. See
Locate the rotor adjustment screw on top of the actuator. Using a
flat-bladed screwdriver, rotate the valve rotor counter-clockwise until it
stops, then back it off a small amount. This sets one end of the rotor's
motion. See Figure
Tighten the adjustment set screw.
Reconnect the air supply and turn it on.
Using a control module or data system, turn the valve ON.
Remove the two screws that secure the actuator assembly to the valve
box, then remove the actuator assembly. Examine the rotor index pin. The
rotor index pin should be fully clockwise without touching the stop.
An off-white rotor is made of a PTFE composite and may be used from
room temperature to 200°C.
A black rotor is made of polyimide and may be used from 100 to 350°C.
6850 Series II GC User Information
Figure
18.
Figure 16) available for the 6850 rotary
Routine Maintenance: General
Maintaining a sampling valve (rotary type)
18.
Rotor adjustment screw
Adjustment set screw
page 112 of 256