Emerson Daniel 762, User Manual

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8.4 Applications
NOTICE
The Daniel Models do not comply with any internationally over-pressurization protection
recognized codes. What the Daniel Models do is to allow the movement of an undetermined
amount of substance
within a pressurized system, not from a pressurized system.
Back pressure control
The Model 762 is ideally suited for back pressure control and minimum pressure drop.
When line pressure exceeds the gas pressure, the valve will open and follow the C
v
curve
for pressure loss.
Typical applications for minimum back pressure control requirements are illustrated in
Figure 8-2 .
• Reference API Chapter 5 for minimum back pressure requirements of the turbine
and ultrasonic meters.
• On the end of a pipeline or any point along the pipeline where the upstream
pressure is subject to drop below minimum requirements.
• Discharge of centrifugal pumps to maintain maximum efficiency and to start against
a closed valve.
Back pressure control Figure 8-2:
Pipeline pump station by-pass
Most pipeline have booster pumps at intervals along the pipeline. If a pump station is shut-
down, it must be by-passed or the entire pipeline is subject to being shutdown. The Model
766 control valve, when installed as shown in
Figure 8-3 , will automatically open and by-
pass the pump station when line pressure exceeds set point.
Operation parameters
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