Fluid Analysis - The Best Maintenance Tool for Extending the Life of Thermal Oil

Improper operating procedures, using water to flush out a thermal oil system, and incorrect layout of equipment can cause oxidation, thermal cracking, and contamination, all of which can lead to the degradation of thermal oil over time. By performing fluid analysis on a regular basis, you can determine when it's necessary to perform system maintenance and/or thermal oil replacement. Fluid analysis programs are typically available from your thermal oil vendor at no extra cost to you or for a nominal fee.

When you first start using a thermal oil system, you should perform fluid analysis regularly in order to monitor how often the system requires fluid changes. The manufacturer of the thermal oil will most likely provide you with guidelines regarding the life expectancy of the fluid, but a number of factors, including the operating temperature and environment, can affect the life of thermal oil. As such, the only way to truly know how often thermal oil should be changed is through conducting fluid analysis.

Fluid analysis programs are also an important part of keeping up with the maintenance of your thermal oil system. Fluid analysis enables you to detect fluid changes so you can make corrections early on in order to prevent degradation and improve the fluid's condition. By performing regular fluid analysis, you can take corrective action before the efficiency of your equipment and thermal oil are compromised.

A fluid analysis program consists of having the manufacturer test samples in a laboratory, evaluate laboratory data and system performance over an extended period, and provide the user with recommendations on how to extend the life of thermal oil. When evaluating laboratory data, the operating history of the thermal oil system must also be considered in order to perform a complete system analysis because laboratory data only provides a snapshot of the thermal oil's condition. Prior to completely changing a system's thermal oil, it's important to do a thorough analysis of the system and be sure of the thermal oil's condition.

Tests Performed in a Fluid Analysis Program

The tests performed in a fluid analysis program detect thermal cracking, oxidation, and contamination. Tests to spot thermal cracking include those for distillation range, fluid flashpoint, kinematic viscosity, and pentane insolubles. When the results of these tests indicate that there is thermal cracking, thermal oil should be replaced or some other corrective action, such as thorough filtration, should be considered.

To check for oxidation, thermal oil is tested for total acid number (TAN). When thermal oil has a high TAN, it must be replaced completely to prevent the formation of deposits. The Karl Fischer water test is conducted to test for a thermal oil system's contamination by water. When there is too much water present in thermal oil, it can degrade rapidly and cause problems with equipment and operation.

Whether you decide to have a fluid analysis done by the manufacturer of the thermal oil you purchased, or you decide to go with another company, make sure to inform the analyst of your system's performance history so you can get the most value from the analysis. It's recommended to get thermal oil analyzed on an annual basis so you can spot potential problems before they arise, improve the performance of your thermal oil system, and extend the life of the thermal oil.