Calculated assessment of effectiveness of class B fire suppression using automatic fire sprinkler systems

Introduction. The problem of timely activation of fire sprinkler systems is highly relevant for effective fire suppression before the critical moment, when calculated values applied to extinguish the fire, become ineffective. A number of works address the problem of effective application of the fire sprinkler system to Class A fires. The application of such methods to Class B fires has not yet been considered.The model simulating a fire in a room with an automatic fire extinguishing system. The response time assessment model, developed by the co-authors for an automatic water-consuming fire sprinkler system, allows to identify the velocity of flame spreading over the surface of an HFL/CL spillage and the temperature rise rate in the ceiling area in the case of a B class fire.A sprinkler is triggered by the bulb bursting caused by the thermal effect produced by the ascending convection flow. A model has been developed to determine the response time of a fire sprinkler system exposed to the effect of a heat flow, caused by the Class B fire, on a heat-sensitive sprinkler bulb.Activation of a fire sprinkler system by the rate-of-rise heat detector. A model, designated for determining the activation time of a rate-of-rise heat detector, was developed.Examples. A number of examples, illustrating the response time of traditional, deluge, and forced launch fire sprinkler systems, are provided in the article.Conclusions. The obtained formula allows to quickly check the applicability of different types of fire sprinkler systems to ensure the effective protection of premises in which class B fires may break out.

Reduced Copper Piping Corrosion in Sprinkler Facilities

Copper pipes used in fire sprinkler systems are somewhat superior to steel pipes in terms of corrosion resistance. They have been widely used in apartments since 2010, but their firefighting performance has not been firmly established due to leakage caused by pitting. In order to solve this problem, copper pipes need to be replaced by pipes made of other materials such as STS or C-PVC, which, however, would impose an economic burden on the party responsible for maintenance, as well as economic loss to other relevant parties and inconvenience to residents. Although 27 leakages occurred in the E region in 2018, it was found that the number of incidents was reduced to just one case after an application of corrosion inhibitor. Therefore, for 2 months beginning in October 2020, a second project to reduce piping corrosion was conducted with 2,000 households in five regions nationwide. During this period, the standing fire water of five apartment buildings in the A region was measured as having a pH 8.34–9.08, an ORP -94.9–-135.8 mV, and an EC 0.097–0.137 ms/cm, which indicated a need for improvement. Subsequently, a corrosion inhibitor was poured into the fire water, resulting in improved values of pH 11.13–11.26, ORP -257–-265.5 mV, and EC 4.189–5.769 ms/cm, which demonstrated the effect of preventing pipe corrosion. It was evident that water-soluble silicate was adsorbed on the metal pipe of the anode to form a thin monolayer, which induced basicity by increasing the pH and by decreasing the ORP, which eventually minimized corrosion.

Design and Development of Corrosion Resistance Coating for Pipes in Fire Protection Sprinkler Systems : A Review

Fire pumping systems are often used in most buildings for firefighting, whether they are residential, commercial, industrial or of any other kind. Such systems are responsible for the water flow and pressure necessary for manual or automatic devices designed to build safety. Therefore, ensuring their availability when an unexpected fire event occurs is very critical. But due to the presence of dissolved oxygen in the water-filled in the pipes, corrosion takes place at some point in time. This will lead to several types of failures in the system if the system is not properly designed with the right material for the environmental conditions and water quality, which in turn will render the system ineffective. This paper discusses the reasons for corrosion in the piping of fire sprinkler systems and their mitigation.