Fluid Components International FLT Series Rack Mount - Manual (Page 34)

Doc. No. 06EN003250 Rev. N/C 4 - 1 FLT  Series FlexSwitch  Rack Mount
CHAPTER 4 - MAINTENANCE FLUID COMPONENTS INTL
4. Maintenance
Warning: To avoid hazards to personnel, ensure that all environmental isolation seals are properly
maintained.
Introduction
The instrument requires very little maintenance because there are no moving parts or mechanical parts subject to
wear. The sensing element has been constructed from stainless steel with nickel braze and is only susceptible to
chemical attack based on the corrosion relationship between the metal and braze and the process media. For
optimum instrument performance, the sensing element thermowells should be kept clean.
General Maintenance
Without detailed knowledge of the application, surroundings, and process media; FCI cannot make specific
recommendations for periodic inspection, cleaning, or testing procedures. However, some suggested general
guidelines for maintenance steps are offered below. Use operating experience to establish the frequency of each type
of maintenance.
Calibration
Periodically verify the instrument's calibration and re calibrate if necessary (every 18 months minimum).
Electrical Connections
Periodically inspect the connector and, if appropriate, the terminal strip connections. Verify that the connections are
tight and physically sound with no sign of corrosion.
Electrical Wiring
Periodically inspect the power wiring; relay wiring; and if appropriate, the signal output and sensing element to
control circuit field wiring. Inspect the conductors for corrosion and check the cable insulation for signs of
deterioration.
Enclosures
Periodically verify that the moisture barriers and seals protecting the control circuit are adequate and that no
moisture is entering the enclosure. If appropriate, verify that the moisture barriers and seals protecting the terminal
strip in the local enclosure are adequate and that no moisture is entering the enclosure.
Sensing Element Process Connection
Periodically verify that all process connection seals are performing properly and that the process media is not
leaking. Check for deterioration of the gaskets and environmental seals.
Sensing Element
Periodically remove the sensing element for inspection based on historical evidence of debris, foreign matter, or
scale buildup and appropriate plant shutdown schedules and procedures. Check for corrosion, stress cracking, and/or
buildup of oxides, salts, or foreign substances. The thermowells must be free of excessive contaminants and be
physically intact. Any debris or residue buildup could cause inaccurate switching. As necessary, clean the sensing
element with a soft brush and available solvents that are compatible with stainless steel and nickel braze.