Linesense is a supplier of Continuous Linear Heat Detection cable for Floating Roof Tanks, Tunnels, Cable Trays, Conveyors, Bus and Coach Protection and has been manufactured for over 40 years. During this time, over 10 million metres of LHD cable have been supplied to customers worldwide, from Europe and The Americas to China and Asia Pacific. In-depth research and development, together with meticulous quality assessment, has always formed the cornerstone of Linesense’s approach to market.
The simple and proven technology of digital Linear Heat Detection (LHD) cable, makes it a product of choice for difficult and challenging applications where other technologies struggle to work. With it’s ease of installation and low maintenance it also provides a cost effective solution where project expenditure requires to be kept at a minimum.
The sensing cable is formed from a pair of twisted steel conductors each with temperature sensitive insulation and then an overall Nylon outer sleeve. When the temperature sensitive insulation reaches it’s predetermined alarm temperature the two conductors short together providing the digital or switched signal. The cable can be connected to any unit capable of monitoring a switched signal, i.e. Conventional fire panel, addressable switch monitor unit or PLC.
The Digital Interface Module (DIM) monitors the Linear Heat Detection (LHD) cable for both Fire and Fault (open circuit) conditions. Using an additional series resistor, it can also offer discrimination of a short circuit fault on the interposing field wiring.
With the ability to monitor up to 5000m for both Fire and Fault conditions the DIM enhances any fire detection capability and allows an appropriate action to be taken.
The DIM has volt free relay outputs for Fire and Fault which can be configured for connecting directly into a conventional fire alarm panel or addressable interface module.
As well as having Fire and Fault indicators built in, it has two pairs of outputs for driving remote LED indicators for Fire and Fault.
The Digital Location Interface (DLI) monitors the Linear Heat Detection cable and identifies the location of the active alarm. The distance is then displayed in meters on the 3½ digit LCD.
The DLI is able to monitor up to 2000m for both Fire and Fault conditions. This enhances any fire detection capability and allows an appropriate action to be taken.
The DLI also offers flexible interface options, designed as a two-wire device for connecting directly into a conventional fire alarm panel. It also has the ability to signal via volt free relay contacts for Fire and Fault, plus a 4-20 mA output.
IP 65 weatherproof lockable Polycarbonate enclosure with M20 and M25 cable gland knockouts.
The Digital Location Interface (DLI) monitors the Linear Heat Detection (LHD) cable and identifies the location of the active alarm. The distance in meters is then displayed on the 4-digit LCD.
The DLI is able to monitor up to 10,000m for both Fire and Fault conditions the DLI enhances any fire detection capability and allows an appropriate action to be taken.
There are flexible interfacing options, designed as a two-wire device for connecting directly into a conventional fire alarm panel, it also has the ability to signal via volt free relay contacts for Fire and Fault, plus a 4-20 mA output.
IP 65 weatherproof lockable Polycarbonate enclosure with M20 and M25 cable gland knockouts.
Floating roof storage tanks usually contain highly flammable products which can potentially cause catastrophic fires. When the fire is not detected early it can causesignificant loss of plant, down time of production and in severe situations even risk to life. These can have a large financial or environmental impact.
The main cause of fires is the ignition of flammable vapours leaking from a worn or damaged rim seal.
Early detection of the incipient fire is paramount for any fire suppression measures preventing the growth and spread of the fire.The design and size of storage tanks can differ with each operator and site, requiring a flexible solutionto meet individual needs. With its ease of installation and low maintenance Linesense digital Linear Heat Detection (LHD) cable provides a cost effective answer. The LHD cable can be cut to length as required and a single cable can protect the largest of storage tanks.
Linesense Linear Heat Detection cable is simple and reliable, providing uninterrupted detection along its length ensuring the complete circumference of the rim seal is protected.
The LHD cable installed around the rim seal of a floating roof tank requires an electrical connection between roof level and a junction box at the top of the tank wall. The connecting cable needs to allow for the rise and fall of the floating roof as the tank fills and empties. The cable reeler automatically adjusts for the movements of the roof, dispensing cable out as the level falls and reeling cable back in when the level rises. The Automatic Cable Reeler is installed at the top of the tank wall and provides a four-core cable to connect to a junction box located on the tank roof.
End Of Line (EOL) units are used in conjunction with the Interface modules to terminate the Linear Heat Detection (LHD) cable and contain the appropriate EOL component or device. This allows the modules to monitor the LHD for any open circuit fault conditions. Units fitted with test switches allow the alarm system to be tested for Fire and Fault conditions without the need for destructive use of any LHD. The units are available in several different materials to suit different applications and environments.
