February 12, 2013

Gas and Flame Detection: Building an Effective Multi-tiered Solution for Reliability and Safety

Ensuring safety for personnel and protection of facilities and equipment is a top priority for all industrial plants. A critical element of this is the effective detection of dangerous flammable and toxic gases and vapors and their potential ignition. However, building an effective safety monitoring solution is a complex task as there is no single system or technology that would be the solution for every plant. There are several fundamental choices available in detection technologies. Jonathan Saint from Emerson Process Management, Net Safety recently published an article with Facility Safety Management that addressed the available options and how to build a solution that works for your plant while saving lives, property and dollars.

An effective solution requires three levels of detection. Safety systems that deploy a diverse range of safety technologies can counteract the serious impacts of gas leaks and the potential for fire and explosions. The article entitled Three Levels of Detection Safety Monitoring: Combining Technologies for Reliable Results addresses the different types of gas and flame detectors, including point type, line of sight, ultrasonic and flame detectors, and their strengths and weaknesses and how to build an optimal solution using an effective combination of these. Read the full article HERE. Following is an excerpt:

Safety systems that deploy a diverse range of detection technologies can counteract the serious impacts of gas leaks and potential for fire and explosions. A combination of ultrasonic leak detectors, fixed gas monitors and flame detectors, is particularly effective because they’re complementary and cover the three detection defense levels.

The first stage is the immediate leak stage, which has the greatest opportunity for fast and effective mitigation; the second is during the gas cloud formation or accumulation stage, which is a very serious safety condition; and the third is during the ignition state, which can be catastrophic.

Ultrasonic detectors are often installed outdoors to cover wide areas with challenging detection conditions. Point detectors should be installed at or near known high-risk gas leakage points or accumulation areas to provide information on the level of gas present in these areas. Open-path gas detection systems are more effective at plant or process area boundaries. They monitor the plant perimeter and provide an indication of overall gas cloud movement in and out of the facility.

The movement of gas clouds throughout the facility is tracked by monitoring the output signals of all the gas detectors within the safety system. Optical flame detectors monitor wide areas for IR or UV energy related to the ignition of a gas source and provide instant alarm condition back to notification and mitigation systems.

A variety of challenging factors affect the performance of these technologies; location (indoors/outdoors); air flow; gas properties (type, density, buoyancy); environmental conditions like temperature and humidity; background conditions (false alarm sources); and obstruction. Best practices for each application will be different, but it’s critical to perform proper HAZOP analysis and identify the sequence of events leading up to an accident.

Every safety engineer that is committed to safeguarding personnel, plant and productivity, and employing a system that provide comprehensive, tiered coverage can yield optimal results before an escalated incident occurs.

To read the full article, click HERE.

Are you providing the optimal safety coverage within your applications?