Local temperature indication should be provided for process equipment and piping where required for manual field control. Such temperature indicators should measure outlet water temperature from all condensers or coolers, discharge of all blowers, discharge of each compressor cylinder, and lube oil and water for pumps, turbines, compressors and similar mechanical equipment.
• Heat exchanger thermowells. Thermowells should be located at the inlets and outlets of heat exchangers (shell side and tube side) that don’t have remote temperature indicators. If a thermocouple point or dial thermometer is present temperature test points are not needed
• Compressor temperature alarms and shutdowns. High discharge temperature alarms are necessary on each cylinder of a main reciprocating compressor and, frequently, on other compressors as well. Thermocouples and thermistors may be used for this service; filled thermal systems should not be. Because high temperatures must be detected at very low or zero flow, the sensing point should be either in the compressor nozzle or immediately downstream of it