Flex-Flame HCF cable withstands high temperature during tests.
How They Work
The Flex-Flame HCF cable offers unique temperature and thermal properties that give off a cooling effect which enable it to withstand high-heat temperatures normally associated with a fire. The design is based on the fire-resistant elastomeric Flex-Flame (BFOU) cable that is surrounded with several layers of composite protection. When exposed to high-heat environments, the outer protection of the Flex-Flame HCF cable begins to foam and generate crystal water that "cools" and forms a firm, ceramic substance around the cable.
However, the unique protection gives effective heat transmission during a normal operating temperature, thus reducing the requirement for derating. This unique composition gives the cable the ability to withstand temperatures ranging from 750[degrees]C to 1,100[degrees]C for up to 60 minutes, even though copper melts at approximately 1,083[degrees]C. In comparison, when exposed to a hydrocarbon fire, a typical IEC 60331-21 designed cable will break down after two to six minutes, making the Flex-Flame HCF cable one of the most fire resistant in the industry.
Rigorous Testing Process
The Flex-Flame HCF cable withstood numerous pilot tests in various temperatures and conditions. For instance, ExxonMobil has defined its own criteria for cable performance during fires in ExxonMobil GP 14-03-01. In this criteria, the cable used in critical systems needs to be able to operate at 2,000[degrees] F, with a heat flux of 160kW/m 2, for at least 15 minutes.
With the assistance of Draka Norsk Kabel personnel and Incore Cables Netherland personnel, Harold L. Phillippi, P.E., Senior Engineering Associate, ExxonMobil Research and Engineering, Safety, Risk and Fire Protection, put the Flex-Flame HCF cable to the test. Numerous pilot tests were conducted by the group at Draka's cable manufacturing facility in Drammen, Norway. As a result of the testing, Flex-Flame HCF cable proved to be fire resistant after being subjected to propane furnace tests that exceed ExxonMobil's requirements. Phillippi said the Flex-Flame HCF cables have been tested and meet all ExxonMobil requirements for fire-resistant cable.
The Flex-Flame HCF cable is flexible, easy to install and terminate, compared to similar products such as cables protected with extra thermal insulation (cements blocks or mineral wool), have the disadvantage of a higher derating factor or installation costs. Additionally, other alternatives such as mineral-insulated cable have the disadvantage of alloy conductors, which require larger conductor cross-sectional areas and complex, time-consuming installation.
Finally, in installations where the enclosure and the cable have the same fire rating, the glanding area must be given the same fire protection. To meet this need, Draka has developed an HCF gland protection kit and installation instructions for easy and safe terminations.
Available in two options, all Flex-Flame HCF cable have an LSFROH outer sheath and can withstand 1,100[degrees]C temperatures for up to 60 minutes. In addition, the 250V and 1 kV BFOU-HCF series, which contain a mica glass tape, pass both the IEC 60331-21 gas flame test for a minimum of 90 minutes at 750[degrees]C as well as IEC 60331-31 with hammer shock for 120 minutes at 850[degrees]C without short circuiting. Also offered is an upgraded IEC 60331-21 test at 1,000[degrees]C for three hours. Additionally, the MV RFOU-HCF series also passes the IEC 60331-21 gas flame test for a minimum of 90 minutes.
Additional information about the FlexFlame HCF cable and Draka Marine, Oil & Gas International can be found at www.DrakaMOG.com.
Eivind Nesset, Technical Manager Innovation Team, Draka Marine, Oil & Gas International
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|Title Annotation:||Tech Notes; HydroCarbon Fire cables from Draka Marine, Oil & Gas International|
|Comment:||Flex-Flame HCF cable withstands high temperature during tests.(Tech Notes)(HydroCarbon Fire cables from Draka Marine, Oil & Gas International )|
|Publication:||Pipeline & Gas Journal|
|Date:||Aug 1, 2006|
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