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provides cavitation-control for applications with
entrained particulate that could potentially plug
the flow passages or cause severe erosion damage
to conventional anti-cavitation trim.
The DST design uses a combined axial and radial
flow path that features large openings allowing
particulate up to 19 mm (¾-inch) in diameter to
pass through the valve.
Due to the need for tight shutoff, this multi-stage
trim incorporates a protected seat design that
separates the shutoff and throttling locations. All
significant pressure drops are taken downstream
of the valve seat. As a result, the seating surfaces
are not worn away by throttling control action, so
shutoff capabilities are extended.
DST is an expanding flow area design. Each stage
has a successively larger flow area. The result is
very efficient operation, because typically 80% of
the pressure drop is taken prior to the final stage
where there is little danger of cavity formation.
Consequently, a relatively low inlet pressure to the
final stage is achieved.
n 2, 3, 4, 5, or 6-stage trim
n Globe or angle body
n ASME Class 150 - 2500
n NPS 1 - 24
n Flow-down or flow-up design
n 290 bar (4200 psi) pressure drop limit
n ANSI/FCI Class V shutoff
n Can be used in easy-e™, EH, EHA, EW, HP,
and HPA valves
n Ability to pass 19 mm (¾-inch) particulate
depending on valve size
14 | Fisher
®
Cavitation-Control Technologies
Dirty Service Trim (DST)
PRODUCTION: Oil and gas production.
APPLICATION: Produced water injection.
CHALLENGE: High pressure drop, particulate, and tight shutoff needed.
SOLUTION: Fisher Dirty Service Trim (DST).
RESULTS: Cavitation control with no cage plugging, long-term shutoff, and extended time
between shutdowns.
PROVEN RESULTS