Refineries and chemical plants must be able to detect gas leaks in order to comply with U.S. EPA Method 21 and Leak Detection and Repair (LDAR) programs. According to the EPA document, the method is applicable for the determination of Volatile Organic Compound (VOC) leaks from process equipment.
“Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects.
The sources of the leaks include, but are not limited to, valves, flanges and other connections, pumps and compressors, pressure relief devices, process drains, open-ended valves, pump and compressor seal system degassing vents, accumulator vessel vents, agitator seals, and access door seals. These items can be found in the hundreds, even thousands, at oil and gas refineries.”
One energy supplier reports that it tests the emission levels of over 320,000 refinery components with high-tech sniff sensors (sorry, it doesn’t involve a cute puppy). If the levels are higher than they are supposed to be, the leaks are fixed. (You can view their video here: Sniffin’ 101.)
The instrument used to do the ‘sniffin’’ is a toxic vapor analyzer. These analyzers are portable gas leak detectors that can quickly detect fugitive emissions of organic and inorganic compounds for Method 21 compliance, LDAR applications and site remediation.
As specified in the EPA Method 21 document,
6.5 The instrument shall be equipped with a probe or probe extension or sampling not to exceed 6.4 mm (1/4in) in outside diameter, with a single end opening for admission of sample.
6.6 The instrument shall be intrinsically safe for operation in explosive atmospheres as defined by the National Electrical Code by the National Fire Prevention Association or other applicable regulatory code for operation in any explosive atmospheres that may be encountered in its use. The instrument shall, at a minimum, be intrinsically safe for Class 1, Division 1 conditions, and/or Class 2, Division 1 conditions, as appropriate, as defined by the example code. The instrument shall not be operated with any safety device, such as an exhaust flame arrestor, removed.
The more advanced analyzers are equipped with a Flame Ionization Detector to measure organic compounds with high sensitivity. The FID technology allows for a wide dynamic and linear range that produces stable and repeatable responses. The analyzer can be configured with both FID and Photo Ionization Detection (PID) technology for simultaneous detection and enhanced analytical capabilities. This dual configuration is capable of producing a more rapid reading of organic and inorganic compounds as opposed to a single detector technology and provides more comprehensive gas coverage than comparable size devices.
It takes more than the human nose or even a cute puppy’s nose to do proper sniffing. Using toxic vapor analyzers enables oil refineries and chemical plants to help ensure there is no gas leak that could threaten the air quality and the environment.
View the video: Sniffin’ 101.