Special hazard fire detection & actuation
Where almost perfect isn't good enough
Since 1964, Alison Control has designed fire detection and actuation systems for environments where a failure costs lives and millions of dollars. Every system is engineered from the ground up for the site it protects — never adapted from a catalogue.
A888 Series Control Systems
Renowned for fire detection and control across a wide range of industrial environments, the A888 Series is custom-designed to the exact needs of the application and the requirements at the specific site.
What makes the A888 unusual is breadth: a single system can monitor the complete spectrum of detection devices and trigger the appropriate response actions. Control effectiveness scales from a relatively simple single-zone analog system through to a highly complex, multi-zone microprocessor-controlled installation.
Unlike off-the-shelf systems, which may not be precisely what an installation needs, A888 systems are developed and engineered only after our experts have met with the customer, reviewed exactly what is being protected, and understood every factor specific to the application and location.
9090 Continuous Thermal Sensor
A small-diameter coaxial wire that senses temperature change along its entire length — not at a point, but everywhere it runs.
The sensor is built from a centre conductor inside an Inconel 625 outer sheath, electrically insulated by a ceramic thermistor material. Because the thermistor has a negative coefficient of resistance, resistance between centre wire and sheath falls exponentially as ambient temperature rises.
Connected to the appropriate A888-Mxxx control panel, the 9090 can hold multiple independent adjustable fixed set points, act as a rate-of-rise detector, identify the location of a hot spot, give a constant temperature readout during an incident, and serve as a temperature measuring device for process control.
Not a fixed-temperature device
The 9090 should not be confused with fixed-temperature open-circuit devices that close only when a preset temperature or rate of rise is reached — fusible-salt detecting wire, rate-compensated thermostats, or twisted insulated steel pairs. None are as versatile or as reliable.
| Diameter | 0.085 in (2.16 mm) |
|---|---|
| Response time index | RTI 58 |
| Sensing range | 70 °F (21 °C) to 1,200 °F (649 °C) |
| Survivable extremes | −60 °F (−51.1 °C) to 2,000 °F (1,093 °C) |
| Standard lengths | 25 ft / 50 ft (7.6 m / 15.24 m) |
| Maximum assembled | 1,000 ft (305 m) via sealed connectors |
| Radiation exposure | Tested to 200 megarads |
| Certification | IEEE 323 & IEEE 344 |
Sensor length & mixed ranges
Shorter lengths are available on special order. Longer runs are assembled from shorter sections coupled with hermetically sealed connectors — and sections of different temperature ranges can be combined, so hazards with differing ambient conditions can be protected economically by a single continuous run.
High Expansion Foam Systems
High Expansion Foam totally extinguishes both major classes of fire — Class A, where quenching by water is effective, and Class B, where smothering action is required.
- Total system reliability. All solid-state supervision makes the system entirely self-monitoring, including motor windings.
- Water-saving. A minimum volume at very low pressure does the maximum job; what water is used is used efficiently.
- Product-sparing. Lower water content means less damage to what you're protecting.
- Limits smoke damage, and the detergent properties of the foaming agent give a self-cleaning effect.
- Non-corrosive and easy to clean up — no messy, sticking residue.
- Thermal insulating barrier for personnel and product protection.
- Three-dimensional. Foam works around obstacles, suiting both total flooding and local application.
On local application, a couple of feet of HEF will extinguish a two-dimensional fire. It is as effective on alcohol and LNG as on hydrocarbons such as gasoline, kerosene and JP-4 — inside or out, subzero or tropical, at high or low altitude.
Group II aircraft hangars — NFPA 409
NFPA 409 defines a Group II hangar as one with an aircraft access door height of 28 feet or less and a single fire area no greater than 40,000 square feet. The most cost-effective way to protect these hangars is a High Expansion Foam system as described in chapter 4 of the standard.
Group II hangars are typically rural, with water supplies inadequate for most system types — but usually sufficient for HEF. Hangars are also cluttered with rolling tool kits, work stands and nested aircraft, which makes low expansion foam slow to deploy. HEF is the most efficient way to extinguish a fuel spill blaze, the worst potential scenario for a hangar and its contents.
Discuss an application
Tell us what needs protecting. Our engineers will review the hazard, the environment and the applicable standards before proposing anything.
Tel 973.575.7100
Fax 973.575.3647
Email info@alisoncontrol.com
Address 35 Daniel Road West
Fairfield, NJ 07004