Now available in Southern Africa through Energas Technologies, a leading supplier of high-end and specialised equipment to the oil and gas industries in the region, is a new, innovative range of detonation flame arresters from leading US-based manufacturer, Protectoseal, which sets a new era with its ability to act as a deflagration and detonation flame arrester simultaneously.
Technology is developing fast, and while innovation is taking centre stage, versatility remains right up on the checklists of both manufacturers and end users alike. With that in mind, the new Protectoseal Series 26000E / 36000E bi-directional overdriven / unstable detonation arresters, now available in southern Africa through Energas Technologies, effective August 2017, usher in a new era in flame arrester technology with their versatility, allowing them to withstand both deflagration and detonation flame fronts.
Deflagration and detonation are two forms of combustion. If the combustion process propagates outward at subsonic speeds and pressures less than 0,5 bar, it’s a deflagration. If the explosion moves outward at or above the speed of sound (343 m/s), it’s a detonation. On the other hand, a detonation is a dramatic, often destructive form of an explosion. Detonation is divided into two types: stable detonation and unstable detonation. Stable detonation is characterised by the speed of sound, while unstable detonation is characterised by supersonic speed in excess of the speed of sound and up to 2 000 m/s with significant overpressure of up to 40 bar. In piping applications, selecting the right flame arrester – whether for deflagration or detonation – often involves the trouble of determining the probable type of combustion, location and other factors.
“The beauty of our new Series 26000E / 36000E bi-directional overdriven / unstable detonation arresters is that the flow and pressure drop performance for these units are extremely competitive compared to other manufacturers’ devices,” says Lavenda Sekwadi, Process Engineer at Energas.
“Protectoseal’s Series 26000E / 36000E detonation flame arresters are designed to withstand deflagrations, as well as stable detonations overdriven/ unstable detonations. These arresters are bi-directional, capable of stopping a flame or detonation approaching from either direction of a piping system,” adds Sekwadi. Available in sizes from 2 inches (DN50) to 12 inches (DN300), the new range has a maximum operating pressure of 1,22 bar and maximum operating temperature of 60 ⁰C.
Series 26000E / 36000E in detail
The Series 26000E / 36000E detonation flame arrester designs utilise improved-flow, crimped metal flame arrester elements. The range comes with high-strength, welded housing, both hydrostatically and pneumatically tested.
Protectoseal’s Series 26000E / 36000E detonation arresters are suitable for short time burn when additional external safety equipment is properly used in accordance with the requirements of EN ISO 16852. Short time burn arresters are equipped with two half-inch FNPT taps for the installation of ATEX-approved, intrinsically-safe temperature probe assemblies. The temperature probes are used to detect a burn on the flame arrester element and send a signal that will trigger emergency functions within a burning time of 50% of the specified burning time.
Stable vs. unstable detonation arresters
Unstable detonation arresters are required for safety in piping containing flammable vapours, as encountered in vapour recovery or manifolded tank systems. “A confined flame front will accelerate from the point of ignition, quickly reaching the speed of sound in the pipe run. During the unavoidable transition period from subsonic to supersonic speeds, flame front pressures and velocities are far greater than before or after the transition (an unstable detonation),” explains Botha.
Devices approved under ISO 16852 as “stable detonation arresters” have not been tested against the severe mechanical and thermal effects of multiple unstable detonations. The use of stable detonation arresters is based on the premise that, firstly, it is unlikely that the unavoidable high pressure and velocity transition will occur as the flame front reaches the detonation arrester and, secondly, all of the independent safety systems required to be installed when stable detonation arresters are used will function properly.
About Energas Technologies:
Energas Technologies has been a leading supplier of high-end and specialised equipment to the oil and gas industries in Southern Africa since 2001 and is the distributor for Mokveld in South Africa.
The company’s core focus is to support and supply equipment to the natural gas industry and its products find application from the gas well, through the distribution network right up until the end user. Applications include, next to the Mokveld axial valves, pressure reduction and metering stations, pipeline ball valves, HDPE pipes and fittings, pig launching and receiving stations to domestic metering and regulating units. Energas can provide complete skid-mounted high pressure reduction and metering stations with gas-fired or electric heaters.
Energas Technologies offers a range of new products from its supplier, HTT energy GmbH in Germany. Products include fired heaters, indirect heating and cooling units from -80°C to 400 °C, and heat recovery products.
Energas’ secondary focus is on liquid storage tank protection equipment, such as conservation vents, flame arresters and emergency vents. Its products, such as valves, filters, flange insulating kits and process heaters, also find application in other industries, such as liquid pipelines, petrochemical and chemical industries.
Energas Technologies is a member of Southern African Gas Association NPC, is 26% black owned and recently obtained its ISO 9001 accreditation.