Brochure

8 | Nonstop High-Cycle Applications
Engineered for Tight Shutoff
Control valve shutoff is a major concern because it affects
purity. If control valve leakage causes contamination
from one PSA bed to another, industrial gas purity can be
compromised. Fisher sliding-stem and rotary control valves
are premier performers in achieving tight shutoff in high-
cycle applications.
Improve Purity
Valve diagnostics in Fisher FIELDVUE digital valve controllers
can detect performance changes by monitoring seat load
and friction. When coupled with ValveLink
™
software,
FIELDVUE instruments alert the user of shutoff integrity
deterioration. Predictive diagnostics allow scheduling of
service before quality suffers.
Excellent Shutoff with
Sliding-Stem Control Valves
Fisher GX control valves meet high shutoff
requirements with the use of PTFE soft seat that
enables long-lasting Class VI shutoff. To further
assure tight shutoff, the unique contours of the
unbalanced plug design only contact the PTFE soft
seat at the moment shutoff is required. The seat
ring centers the plug as it enters the seat so the
valve establishes a concentric seal.
Seat Ring
Plug
PTFE Soft Seat
The Fisher sliding-stem control valve achieves acceptable Class VI shutoff throughout the life of the testing.