Azbil VDC - Table of Contents

VDC, VAC, VST, VAA - Diaphragm Control Valve 1
Table of Contents
Safety Guide
1 : Nomenclature of parts ......................................................................................... i
2 : Safety precautions ...............................................................................................ii
3 : Verication of Valve Specications and Precautions on Storage ........................ii
4 : Installation .......................................................................................................... v
5 : Caution on disassembly and reassembly ...........................................................ix
6 : Assembly ............................................................................................................ x
7 : Maintenance and inspection ...............................................................................xi
Chapter 1 : General
1-1 : Specication of Control Valves .................................................................... 1-2
1-2 : Construction ................................................................................................. 1-2
1-3 : Valve Body Section ...................................................................................... 1-2
1-4 : Actuator ........................................................................................................ 1-2
Chapter 2 : Installation of a Control Valve
Chapter 3 : Inspection and Maintenance of Control Valves
3-1 : Inspection Before Starting Operation. .......................................................... 3-1
3-2 : Periodical Inspection and Maintenance ....................................................... 3-1
3-3 : Lubrication of Gland Packing (for valve with asbestos packing)
(See Figure.3-1) ........................................................................................... 3-2
Chapter 4 : Control Valve Adjustment
4-1 : Lift Adjustment ............................................................................................. 4-1
4-2 : Spring Compression Adjustment ................................................................. 4-2
4-3 : Positioner Adjustment .................................................................................. 4-2
Chapter 5 : Disassembly and Reassembly
5-1 : Disassembly ................................................................................................. 5-1
5-2 : Reassembly ................................................................................................. 5-1
5-3 : Disassembly and Reassembly of Bellows-sealed Valve .............................. 5-2
Chapter 6 : Parts Replacement
6-1 : Replacement of Gland Packing ................................................................... 6-1
6-2 : Replacement of valve plug and Cage of VDC or VAC Control valve. .......... 6-3
6-3 :
Replacement of valve plug and seat ring of VST, VAA, or VAV Control Valve ... 6-4
6-4 : Diaphragm Replacement of Diaphragm Motor (See Figure 1-6, 1-7.) ......... 6-5
6-5 : O-ring Replacement of Diaphragm Motor (See Figure 1-6, 1-7.) ................. 6-6
6-6 : Disassembly and Assembly of Model PSA6 Actuator .................................. 6-7