Fluid Components International RF83 Manual General Information - Manual

Doc. No. 003147 Rev. B 1 - 1 Model RF83 Flow Switch
CHAPTER 1 - GENERAL INFORMATION FLUID COMPONENTS INTL
1. General Information
Description
This document explains the operating principle of the Model RF83 Flow Switch. The following pages also present
the recommended procedures for the installation, operation, maintenance, and troubleshooting of the Model RF83.
The Model RF83 is an instrument that is capable of detecting bi-directional liquid or gaseous flow environments.
The instrument has field adjustable alarm set points for control of the media.
Flow Element
The operational parts of the flow element are the sensing points. The sensing points consist of four thermowells
(hollow tubes). There is two pair of thermowells welded together. The thermowell pairs have a heater in one
thermowell and a Resistance Temperature Detector (RTD) in the other thermowell. The thermowell pairs (sensing
points) are placed on opposite sides of a flow media barrier. There is a baffle placed around the sensing points to
direct the flow across the up-stream sensing point. As the flow media flows from sensing point B to sensing point A
(as shown in Figure 1-1) the flow media removes heat from the up-stream, heated RTD. There is no effect on the
heated RTD A. A delta R (
D R) exists between the two RTD's that the electronics measures. If the flow reverses
RTD A looses heat and not RTD B.
Figure 1-1. Process Installation Showing the Sensing Point