Emissions systems and gas analyzers rely on sample lines, also known as umbilical lines, to carry gas from the source to the analyzer. Proper installation, usage and maintenance of sample lines are important to ensure regulatory compliance and process requirements. Consider these five tips related to umbilical lines:
Knowing and adhering to the recommended maximum umbilical line length is important to system performance and regulatory compliance. If the line is too long, the response time is greater and this puts the system at risk for non-compliance. Due to the nature of mercury and HCL, there is an additional risk for sample loss with longer lines on the Thermo Scientific™ Mercury Freedom System and the Thermo Scientific™ Omni FTIR Multi Gas CEMS. Recommended maximum lengths may be shorter depending on site conditions, but the maximum recommended length for the Thermo Scientific Omni FTIR Multi Gas CEMS is 100 feet and the maximum recommended length for the Thermo Scientific Mercury Freedom System is 500-600 feet.
Temperature and temperature parameters are set at the factory before the instrument is shipped. Staying within this range is critical to prevent adverse affects on the process. The Thermo Scientific Omni FTIR Multi Gas CEMS cannot operate below 185°C or the HCl may go below its dew point, resulting in sample loss and an underreported HCl value. For the Thermo Scientific Mercury Freedom System specifically, a lower umbilical operating temperature can result in longer umbilical life, increased reliability, total operating cost reduction as well as increased operator safety. After extensive testing, the recommended umbilical temperature has been lowered from 120°C to 70°C. For more information see Technical Bulletin Umbilical Line Temperature on the Thermo Scientific Mercury Freedom System.
Sample lines are normally trouble free but sometimes issues arise with heated lines. If the temperature control device, or heat trace, fails, the whole line does not necessarily need to be replaced. Contact the OEM of your umbilical line for repair options. This contact information can usually found on the label of the sample line or transport bundle.
Contaminants may accumulate within sample lines over time and this may lead to elevated background readings, slow responses or calibration issues. To minimize these risks and to extend the life of the umbilical, the lines should be cleaned quarterly. Consult the Thermo Scientific™ instrument user manual*, contact the sample line manufacturer directly, or contact Thermo Scientific Technical Support by email or calling (508)502-0430, option 2.
*How to find operator manuals online
Proper installation is critical to ensuring accurate monitoring and trouble-free umbilical life. During initial installation, be sure to run the line continuously with no loops and always in a downward position to ensure maximum flow. Avoid hot pipes and support the line on the stack with a cable tray. Trimming the line can often be avoided on site if an accurate measurement is taken at time of proposal. When the line needs to be shortened, refer to the detailed instructions supplied by the umbilical line OEM to mitigate the risk of voiding the warranty.