Fisher Design CAV4, Instruction Manual, Page: 1 / 20

D100384X012
Design CAV4 Control Valve
Contents
Introduction
1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope of Manual 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation
2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principle of Operation
4 . . . . . . . . . . . . . . . . . . .
Maintenance
5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Packing Lubrication 5 . . . . . . . . . . . . . . . . . . . . . . . . . .
Packing Maintenance 6 . . . . . . . . . . . . . . . . . . . . . . . . .
Packing Replacement 7 . . . . . . . . . . . . . . . . . . . . . . .
Trim Removal 8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trim Replacement 11 . . . . . . . . . . . . . . . . . . . . . . . . . .
Use of Flushing Trim 13 . . . . . . . . . . . . . . . . . . . . . . .
Parts Ordering
14 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Kits
14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List
14 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introduction
Scope of Manual
This manual includes installation, maintenance, and
parts ordering information for the Design CAV4 control
valve and Cavitrol
IV trim. Information on the flushing
trim is also provided. Refer to separate manuals for
information concerning the actuator, positioner, and
other accessories used with this control valve.
Only personnel qualified through training or experience
should install, operate, and maintain a Design CAV4
control valve. If you have any questions about these
instructions, contact your Fisher Controls sales office
or sales representative before proceeding.
Figure 1. Design CAV4 Control Valve
with Type 657 Actuator
W2700-1*/IL
TYPE 657
ACTUATOR
DESIGN CAV4
CONTROL VALVE
Description
The Design CAV4 control valve, shown in figure 1, is
an angle valve with soft metal-to-metal seats,
Cavitrol IV trim, cage guiding, and push-down-to-close
valve plug action. Figure 8 shows a typical balanced
TSO (tight shutoff) trim construction. Figure 10 shows
three additional valve plug constructions that are avail-
able: one with a pressure-assisted spring-loaded
PTFE seal ring with PEEK (poly ether ether ketone)
anti-extrusion rings, another with five graphite piston
rings, and a third with stem-balancing.
Cavitrol IV trim is most often used to eliminate cavita-
tion damage on liquid service where the differential
pressure drop is greater than 207 bar, differential
(3000 psi). It may also be used in applications with
lower pressure drops where its anti-cavitation perfor-
mance is required. Figure 11 shows the valve with
Instruction Manual
Form 5191
September 1999
Design CAV4