Emerson Daniel 762, User Manual

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8 Operation parameters
Topics covered in this chapter:
• Control valve normal operation
• Features and benefits
• Oil reservoir
• Applications
8.1 Control valve normal operation
All series 700 control valves are pressure balanced, single-seated piston operated with 45°
body construction.
Unique design features and unit-built construction ensures positive leak-proof
performance. In addition, the basic valves body and internals are the same throughout the
line, simplifying spare parts inventory and reducing costs.
8.2 Features and benefits
• Balanced piston principle, spring biased
• Linear valve action: Rectangular ports provide smooth linear action with maximum
flow and minimum pressure drop
• Uniform speed of response: Uniform area above main piston provides uniform
opening and closing.
• Positive (pressure type sealing) O-ring seal and valve seats are not affected by fluid
viscosity or pressure drop
• High capacity 45° (in-line) valve body ensures high capacity at low pressure drop
• Zero leakage: Contoured edge of piston provides a tight seal and ensures drip-tight
operation and dead-end service
• Unit-built construction: All internal parts, including seat ring, can be removed as a
unit without disturbing valve body and connections.
• Simple design: No diaphragms or stuffing boxes
8.3 Oil reservoir
The Oil reservoir is supplied with two (2) sight gauges. In a closed position, the oil is visible
only at the lower sight gauge. Should oil be visible in the upper sight gauge, this indicates
line product is leaking into the reservoir or that the valve is open. If no oil is visible in the
lower sight gauge, this indicates the reservoir oil is leaking into the product stream.
Operation parameters
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