
BT- 434 Rev.A
15
Instrumentation Circuits
The instrumentation consists of a pressure gauge and differential pressure gauge. The pressure gauge
(PI-1) displays the inner vessel pressure in pounds-per-square-inch and kilopascals. The liquid level
gauge (LI-1) measures the difference in pressure between the top and bottom of the vessel. Product
within the vessel creates a higher pressure at the bottom of the vessel than at the top. Readings on the
liquid level gauge are in inches of water. This reading, when compared to the contents chart attached
to the front of the vessel, allows accurate monitoring of the amount of product within the vessel.
Instrumentation Circuits
Figure 8-Instrumentation circuits highlighted in blue.
LI-1
PI-1