Page 10 - OHS, November/December 2021

TRAINING: IH: GAS DETECTION
LAYER 1A
LAYER
Ultrasonic Gas Leak Technology
1C
The technology can ‘hear’ the ultrasounds emitted by escaping gas at the speed of sound, buying plant personnel critical time to respond.
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litigation and fines.
Gas and flame detection solutions
provide an early warning against these risks, but no single detection technology alone is 100 percent effective. This is where a layered approach comes in. By integrating the following layers of protection, employers can minimize the risk of flammable gas leaks going undetected and can be better informed to take steps to keep their workers protected.
What is a Layered Approach
to Gas Leak Protection?
To enhance safety on a job site, site management should choose a comprehensive, layered gas detection system. The most effective way to deter, prevent and mitigate potential threats is to employ a layered safety approach in which independent yet interrelated layers of protection work together, offering comprehensive protection and providing confidence. The layered architecture of protection should be created according to the business structure, safety and production levels necessary for effective operations. Security controls should extend across the entire plant and business networks, enabling the facility to protect from potential incidents with an early indication of equipment that is not working properly and leaking harmful gases.
Often, detection systems are comprised of a combination of point detector technology, open-path technology, ultrasonic or acoustic gas detectors and flame detection. This layered approach to protection provides different methods of finding gas leaks that can help site management with its worksite safety plan.
In a mixed technology approach for gas and flame detection, each solution complements the effectiveness of the previous one, adding to the safety case. As each one acts independently, an unexpected issue will not affect more than one layer. For example, for fire and gas detection systems, gas detection and flame detection are two separate layers. If there is an issue with the gas detection layer and a fire ignites, flame detection comes into play. Simply put, more layers of gas leak
detection provide more comprehensive protection. If all technologies outlined below are utilized, industries will benefit from a safer workplace.
Layer 1a: Point Infrared Gas Detection
Point infrared detection3 is often one of the most used options when it comes to flammable hydrocarbon gas monitoring. It can be deployed in large or small areas and confined spaces, especially near potential leak sources such as valves, flanges and pumps, offering a foundational layer of protection. A key advantage of deploying point detectors is that they measure actual gas concentrations at a point in space and time. By installing multiple devices, you can gain a more accurate map of gas release events.
These gas detectors provide continuous monitoring to detect gas clouds that could cause structural damage in case of an explosion. However, the gas must reach the detection point, which does not
happen if the wind moves the gas cloud away from the detector or is dissipated before reaching the detector.
Layer 1b: Open Path Infrared Gas Detection
Open path infrared detection offers a different layer of protection against flammable gases that is less sensitive to wind speed and direction than point detection. Open path gas leak detectors4 play an important role in a facility’s fixed gas detection system, creating an invisible line that senses gases passing between the device’s transmitter and receiver.
Open path devices are available in short and mid-range applications from two to 120 meters (six to 393 feet), allowing workers to monitor specific areas or equipment. They are also available for long range perimeter or fence line monitoring from 60 to 330 meters (196 to 1083 feet), so that worksite employees can both monitor whether they are emitting harmful gases into neighboring areas or if
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Point Infrared Gas Detection
These gas detectors provide continuous monitoring to detect gas clouds that could cause structural damage in case of an explosion.
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LAYER
Open Path Infrared Gas Detection
1B
Open path infrared detection offers a different layer of protection against flammable gases that is less sensitive to wind speed and direc- tion than point detection.
LA2YER
Flame Detection
Flame detection is the final, critical layer of protection when working around flammable gases.
10 Occupational Health & Safety | NOVEMBER/DECEMBER 2021
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