Cable Guard – hydrocarbon fire protection system for cable trays
When a fire breaks out on a petrochemical plant, it is essential that the cabling in cable ducts can continue to transmit a signal long enough to stop the various processes in time. Furthermore, the chance of permanent damage to the cabling must be minimized and the emission of toxic and corrosive gases must be prevented.
The Cable Guard has been developed for protecting cable trays; an easy-to-install system that has been tested and certified for providing 30-minute fire resistance in hydrocarbon fires according to the ASTM E1725-95 standard. This standard is designed to measure the behavior of an electrically charged material during a fire and at high temperatures. This test can be performed under a standard cellulose fire load (ASTM EI 19), or a hydrocarbon fire load (EI 529).
Within the API 2218 ‘Fire Proofing Practices in Petroleum and Petrochemical Processing Plants’ reference is made to the ASTM E1725-95 test method and it is stated that applications within the petrochemical process industry should only be tested based on the hydrocarbon temperatures / time curve .
The Cable Guard is a 50 mm thick fiber blanket, completely wrapped with a reinforced aluminum foil. The blanket is applied in only one layer around the tray, for an easy and fast installation. Due to the flexibility of the blanket and the use of steel straps, the system can also be easily removed for maintenance and inspection.
a. Cable duct with instrument cabling
b. Steel band every 150 mm to support the mesh
c. Steel mesh to prevent the blanket from sagging
d. Steel strap with a width of 12 mm attached at 40 mm from the edge of the blanket. Standard Cabel Guard blanket width is 610 mm. It can also be supplied in double width 1220 mm. In this case, the straps must be installed every 250 mm.
e. Cable Guard blanket with a thickness of 50 mm and a width of 610 mm or 1220 mm. The blanket is completely encapsulated with a reinforced aluminum foil. Installed in a single layer with an overlap of 75 mm.
f. Overlap of 75 mm.