ITT Controls Barton Nuclear 227A - Section 1: Introduction; General Information; Product and DPU Description

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Model 227A Dierential Pressure Indicator Section 1
Section 1—Introduction
General
The Model 227A Differential Pressure Indicator is designed to measure
measurement applications, the instrument is connected to monitor changes in
differential pressure relative to variations of liquid height in a vessel.
Product Description
The indicator has a 6-inch dial. The indicating pointer traverses a 270° arc
Figure 1.1.
The 227A indicator is actuated by a Model 224 Differential Pressure Unit
(DPU). See Appendix A for details.
The indicator is attached directly to the DPU. The instrument consists of
a drive arm assembly, linkage, and a movement assembly. The indicating
pointer is attached to the movement assembly. Changes in differential pres-
sure are sensed by the DPU bellows and transmitted as rotary motion through
the torque tube to the drive arm assembly of the indicator. The linkage and
movement assembly respond to the action of the drive arm assembly to posi-
tion the pointer in direct relationship to the amount of bellows travel.
Pointer Stop
Max. LineZero Line
Pointer
Zero Adjust
Range Adjust (Universal Unit)
Scale Plate
Range Adjust
(Inverted Unit)
Figure 1.1—Instrument face