Linear heat detection has been around for over 80 years but is still relatively unknown to many in the fire protection industry. In this article, we will delve into the construction and operating principles of digital linear heat detection, applications and guidelines for fire protection engineers, the use of NFPA codes and standards as well as FM and UL guidelines.
In 1938 The Protectowire Company invented and introduced the first linear type heat detector. Today, Protectowire offers the largest digital linear heat detection portfolio on the market. Manufactured in the United States, our product activation temperatures range from 135°F (57°C) to 500°F (260°C) and are offered in a wide range of jacketing materials.
Protectowire also offers our patented Confirmed Temperature Initiation (CTI) technology. CTI technology can distinguish between a fault caused by mechanical damage and a fault initiated by an actual heat event. Our CTM series interface modules monitor the CTI cables and identify the location of any alarm or mechanical fault condition.
Protectowire’s fibre-optic linear heat detection is popular for applications requiring longer detection distances (up to 10km) like road tunnels, metro systems, oil pipelines and aircraft hangars. Each fibre-optic detection run can be divided into 256 zones, with each zone able to monitor for a specific fixed temperature, a specific rate of rise value and a temperature differential between zones.
Common applications
Linear heat detection’s most notable attributes are the ability to detect heat anywhere along its length, extended service life, ease of testing, consistent and reliable performance, and ability to offer proximity detection. These attributes encourage the use of linear heat detection in a core group of industries and applications which are, but not limited to, the following:
Power generation (conveyors, cable trays, transformers, switch gear, electrical equipment, cooling towers):
Large drive motors, belts and roller bearings are stressed to the limit in dirty, dusty and sometimes hazardous environments present in the mining industry. Protectowire can be installed over the belt or alongside the conveyor near the bearings for overheat detection. Protectowire’s versatile construction enables it to be installed in, around, or on controllers, switches, motors, or other conveyor components where the risk of overheat or fire is greatest.
Petrochemicals (fixed and floating storage tanks, pipelines, offshore platforms, refineries):
Storage tanks, pipelines, offshore platforms and refineries utilize numerous processes involving flammable liquids and toxic chemicals. Every facet of these processes must be monitored regardless of the hazardous challenges they present. Specialty linear heat detectors allow us to fully serve the petrochemical industry.
Transportation (aircraft hangars, vehicle systems, tunnels, bridges, metro systems, rolling stock):
The highest risk of fire danger within airport facilities is fuel storage, cargo materials and from the aircraft themselves. Both PHSC and CTI series detectors offer minimal maintenance and are not adversely affected by temperature fluctuations, making them ideal detectors for the transportation industry.
Warehousing (freezers, refrigerated storage and self-storage units):
CTI Series linear heat detectors provide the most dependable fire detection solution for cold storage applications. Unlike standard digital linear heat detectors, damage to a CTI detector will not cause a false alarm. Most cold storage facilities utilize double interlocked pre-action systems, which makes the CTI technology ideal for this type of suppression system.
Renewable energy (solar panel arrays, wind turbines, battery storage):
Protectowire technology is the ideal choice for solar panel installations. Unlike traditional spot heat detectors, Protectowire can be placed directly onto the underside of solar panels providing immediate proximity detection for failing or overheating panels.
For more information, go to www.protectowire.com
