Data Sheet

GX Control Valve and Actuator
D103171X012
Product Bulletin
51.1:GX
March 2012
6
Figure 8. Fisher GX Control Valve Assembly with Stem-Guided Contoured Plug (Size DN 25/1-Inch)
W8486-3
COMPACT FIELD-REVERSIBLE
MULTI-SPRING ACTUATOR
INTEGRATED POSITIONER
MOUNTING
NAMUR POSITIONER
MOUNTING CAPABILITY
ONE-PIECE SCREWED
PACKING FOLLOWER
CLAMPED BONNET DESIGN
STANDARD LIVE-LOADED PACKING
INTEGRAL PNEUMATIC PASSAGEWAYS
The Fisher GX Control
Valve
The GX is a single port, flow-upglobestylevalvethat
offers port-guided (figure 1), stem-guided (figure 8),
and balanced trim with a screwed-in seat ring (see
table 1 for a description of trim style availability). Each
valve size offers an unbalanced plug design, which
eliminates dead spaces where fluid polymerization
might occur. Although the optimized GX actuator
allows for wide usage of unbalanced trim, a balanced
plug design is available for higher pressure drop
applications in DN80, 100 and 150 (NPS 3, 4, and 6)
sizes.
The GX incorporates a clamped bonnet and an
easy-to-adjust screwed packing follower (see figure 1).
Theplugandstemarearugged,one-piece welded
assembly.
The standard construction incorporates
metal-to-metal seating, with a PTFE soft seat option for
Class VI shutoff (see figure 5). Class V shutoff is
available with metal trim. Hardened trim with stellite
overlay is available for erosive service, as well.
PTFE V-ring stem packing is standard with t he GX. The
live-loaded system provides excellent stem sealing and
extended service life. Live-loaded graphite ULF packing
and extension bonnets are available for high
temperature applications.
Both linear and equal percentage flow c haracteristics
are available in full port and restricted trim. Micro-Flow
is available for applications requiring low flow control
capability.
Standard valve body materials are carbon steel and
stainless steel. Alloy materials are available for valve
body sizes DN 15 through DN 100 (NPS 1/2 through 4)
for highly corrosive applications.