Data Sheet

EH and EHA Valves
D100042X012
Product Bulletin
51.2:EH
April 2015
11
Figure 14. Sectional of NPS 20 Fisher EHD Control Valve Assembly
W4282-2
SEAT RING
CAGE
VALVE PLUG
AND STEM
ASSEMBLY
FLOW
NPS 20 Globe Valves
The NPS 20 EHD control valve (figure 15) is a large,
high-pressure, single-port, globe valve designed to
closely and dependably control high-pressure,
high-temperature media in the power and
hydrocarbon industries. For example, NPS 20 EHD
control valves are used in sliding pressure systems to
control high-pressure steam in fossil-fueled power
plants.
Advanced, yet successfully field-proven, the NPS 20
EHD control valve usually incorporates special design
features to satisfy specific customer requirements. For
example, figure 14 illustrates a specially characterized
cage. Both Whisper Trim cage holes and large cage
windows provide the customer-required flow
characteristic. Additionally, the drilled Whisper Trim
holes in the cage provide noise abatement.
Standard construction details such as the cone-shaped
valve plug and stem assembly, separate seat ring, and
HIGH-SEAL packing arrangement are also shown in
figure 14.