Brochure

is a multi-stage control valve trim design. It is used
in services where the fluid has dissolved gases
that are released from solution due to a reduction
in pressure. The fluid may also contain entrained
particulate. DST-G is mainly used in refining,
petrochemical, and oil and gas applications.
Outgassing can cause two types of damage.
One type is cavitation, as discussed previously.
The other is erosion from a rapidly expanding
flowstream.
The DST-G trim employs the basic design from
the standard DST trim, but utilizes a different
design for the lower cage. The DST-G lower cage
controls jet formation and discharge into the
body to prevent vibration and erosion. The trim
accomplishes all this while allowing large 6.35 mm
(¼-inch) particulate to pass through.
n Multi-stage trim
n Angle body
n ASME Class 150 - 2500
n NPS 1 - 12
n Flow-down design
n 175 bar (2500 psi) pressure drop limit
n ANSI/FCI Class V shutoff
16 | Fisher
®
Cavitation-Control Technologies
Dirty Service Trim for Outgassing (DST-G)
PROVEN RESULTS
PRODUCTION: Oil renery.
APPLICATION: Hot, low-pressure ash drum.
CHALLENGE: Outgassing, large particulate, and cavitation.
SOLUTION: Fisher DST-G.
RESULTS: Reduced vibration, enabled long seat life, and provided reliable, long-lasting throughput.