An odorizer is a device that is being used to inject an odorant in liquid form into a Natural Gas distribution system for the purpose of leak detection in the NG line. The most prevalent type is the mercaptan odorizer. The amount of odorant that is injected to NG line is being controlled by a flow meter that receives signals from a programmable logic controller (PLC). The odorant injection rate is proportional to the Natural Gas flow rate. The PLC itself can communicate with a SCADA system and send an alarm signals in case the odorizer fails to deliver the required flow rate of odorant (Mercaptan) to the Natural Gas distribution system.
The odorizer system preventive maintenance consists of weekly, monthly, bi-annual, and annual inspections:
During the weekly inspection, the technician will check the PLC panel for any alarm signal and check the number of Auto-clears on the system. if more than half of auto-clears are used, it is an indication of an underlying issue that needs to be investigated. Technician also checks the regulator to ensure system pressure is within an acceptable range. checking the flow meter to ensure Mercaptan Is being released at an acceptable flow rate is also part of this inspection.
During the monthly inspection, the inspector will look at the mercaptan tank for any sign of leakage, check for the acute smell of mercaptan inside the box, also checking the tank level gauge to ensure it is fully functional. In addition, the inspector will check to make sure the servo motor is tightened properly (not too loose or too tight).
During bi-annual inspection, tank will be thoroughly inspected for signs of leakage. Liquid level inside the mercaptan tank will be checked. if mercaptan level drops below 25%, tank must be refilled. Isolation valve and meter valve also should both be checked for proper functionality. battery on CPU is also should be checked and replaced if it is low. Note that bi-annual inspection should include all the steps involved in weekly and monthly inspections.
For annual inspection, power supply should be included in the inspection and be checked to ensure proper functionality. Visual inspection on solar panels and batteries for any sign of damage, changing the filter element and O-rings in the metering valve (if required) should also be included in the annual inspection. Note that annual inspection should include all the steps involve in weekly, monthly, and bi-annual inspections.
The above procedure only outlines a generic preventive maintenance procedure for Mercaptan Odorizers. Refer to the manufacturer manual for details and frequency of preventive maintenance.
If you are looking for a dedicated team of experienced engineers and trade professionals to service and maintain Natural Gas odorizers at your sites, feel free to book a free consultation with Rotaflow’s team of experts.