Azbil FloWing VFR - Page 4

Table of Contents
Chapter 4 : Valve Positioner
4-1 : Smart Valve Positioner (SVP) .................................................................... 4-1
4-1-1 : Description ................................................................................................................. 4-1
4-1-2 : Removing and installing the positioner ...................................................................... 4-1
Removal ............................................................................................................. 4-1
Installation .......................................................................................................... 4-2
4-1-3 : Adjusting the positioner .............................................................................................. 4-2
4-1-4 : Maintaining the positioner .......................................................................................... 4-2
4-1-5 : Troubleshooting ......................................................................................................... 4-2
4-2 : Pneumatic valve positioner (model VFR) ................................................. 4-3
4-2-1 : Description ................................................................................................................. 4-3
4-2-2 : Operating principle ..................................................................................................... 4-4
4-2-3 : Bypass cock ............................................................................................................... 4-5
Function of bypass cock .................................................................................... 4-5
Installing the bypass cock .................................................................................. 4-5
4-2-4 : Selecting cam characteristics..................................................................................... 4-6
Cam characteristics............................................................................................ 4-6
Using the equal-percent cam ............................................................................. 4-6
Selecting a cam ................................................................................................. 4-6
4-2-5 : Removing and installing the positioner ...................................................................... 4-7
Removal ............................................................................................................. 4-7
Installation .......................................................................................................... 4-7
4-2-6 : Adjusting the positioner .............................................................................................. 4-10
4-2-7 : Maintaining the positioner .......................................................................................... 4-11
Operating precautions ........................................................................................ 4-11
Troubleshooting ................................................................................................. 4-11
Cleaning the restriction ...................................................................................... 4-11
4-2-8 : Troubleshooting ......................................................................................................... 4-13
Chapter 5 : Changing the mounting attitude of actuator and
type of valve action
5-1 : Changing the mounting attitude of actuator ............................................ 5-1
5-2 : Changing the valve action ......................................................................... 5-1