Automatic sprinkler systems

There are several types of automatic sprinkler systems. These systems have piping of different sizes with sprinkler heads attached and connected to a large water supply. These heads are heat activated by a fire. They will then discharge water over the fire area. There are basically six types of automatic sprinkler systems. 

The wet-pipe system. The pipes always contain water. Therefore, building temperatures must remain above freezing or provisions must be made for antifreezing solutions. The water does not flow until a sprinkler head starts discharging water. An alarm may signal when this happens. This type of system accounts for 75% of all sprinkler systems presently in operation. 

The dry-pipe system. Water is not kept in the pipes. Thus, this system is used in buildings that have temperatures that drop below freezing. In this system, air or nitrogen is held in the pipes. The valve that controls the water flow must be installed in a heated area to prevent water in the valve from freezing. 

The deluge system. This system permits all sprinkler heads to open and discharge water at the same time. A detection system in the protected area allows for water to flow through the pipes. This a good system for areas of storage for highly flammable materials. 

The pre-action system. This is similar to the deluge system, except that the sprinkler heads are kept sealed for some time before the water comes through. This delay enables firefighters to put out the fire before it is covered by water. 

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Started to rise from the reaction, causing the vessel bottom head to fail at the weld seam. The force from the escaping gases propelled the tank into the ceiling and overhead structural steel. A small fire erupted which was quickly brought under control by the automatic sprinkler system. Even though the chemists had reviewed the chemistry and did not anticipate any problems, use testing could have identified this problem in the laboratory rather than the plant. 

Design ventilation system to keep flammable concentration below lower flammable limit Provide on-line flammable gas detection and activation of inerting system Install automatic sprinkler system Install deflagration vents... 

Provide automatic sprinkler system/inerting gas Provide deflagration vents Provide deflagration suppression system Monitor flammable atmosphere/fire Provide nitrogen blocks (nitrogen injection to stop flame propagation) or other explosion isolation measures... 

Provide automatic sprinkler system Use deflagration vents... 

Sprinkler and water spray installations-Many process and storage area buildings should be protected by automatic sprinkler systems. The size and arrangement for water supply are dependent upon the nature of the hazard and the degree of protection desired. Water spray installations are particularly adapted for cooling uninsulated steel structures, elevated pipe lines, vessels, spheres, and similar plant installations. 

Automatic sprinkler systems have the great advantage that they are comparatively simple in concept and operate automatically, whether or not there are people present on the premises. Water is supplied from the public mains or tanks and pumps into a network of distribution pipes at ceiling level, which covers the whole premises. Water is discharged through nozzles or heads sited at regular intervals in the pipework, which are normally sealed with a he at-sensitive device. 

Calculate the relative number of atoms of each element contained in each of the following alloys (a) Wood s metal, which is a low-melting-point alloy used to trigger automatic sprinkler systems and is 12.5% tin, 12.5% cadmium, and 24% lead by mass in bismuth (b) a steel that is 1.75% by mass carbon in iron. 

Warehouses are normally considered low risk occupancies unless high value or critical components are stored. Some high valve components normally overlooked in warehouses are diamond (industrial grade) studded drill bits or critical process control computer boards. In these cases the economic benefits of installing an automatic sprinkler system should be investigated. 

Automatic sprinkler system protection for Class A and Class B laboratories should be in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems, for Ordinary Hazard (Group 2) occupancies. Automatic sprinkler system protection for Class C and Class D laboratories should be in accordance with NFPA 13, Standard for the Installation of Sprinkler Systems, for Ordinary Hazard (Group 1) occupancies. 

NFPA. 1 997. Automatic Sprinkler Systems Ffandbook, 7th Ed. National Fire Protection Association, Quincy, MA. 

Fire Retardent Paints. Fire retardant paints are based on chlorinated rubber and chlorinated plasticizers with added SbO. These reduce the rate of spread of flames. Addn of NH4H2PO4, PE, or dicyandiamide produces an intumescent or swelling paint that forms a thick insulating layer over the surface to which it is applied when exposed to flames Fire retardant paints do not control fires and are no substitute for an automatic sprinkler system. They are best used where the only hazard is exposed, combustible, interior finish materials or in isolated buildings where sprinklers will not be installed. The paint must be applied at the rate specified on the container if spread thinner the proper... 

Pre-action System A type of automatic sprinkler system in which thennostatic devices are employed to charge the system with water before individual sprinkler heads are fused. 

Wet-pipe Sprinkler System An automatic sprinkler system in which the pipes are constantly filled with water under pressure. 

Wide range of melting points possible with changes in composition for automatic sprinkler systems and other safety devices. 

Bismuth is a rather rare element in the earth s crust, but its oxides and sulfides appear at sufficient concentrations as impurities in lead and copper ores to make its recovery from these sources practical. Annual production of bismuth amounts to several million kilograms worldwide. Although elemental bismuth is a metal, its electrical conductivity is quite poor and it is relatively brittle. The major uses of bismuth arise from its low melting point (271.3°C) and the even lower melting points of its alloys, which range down to 47°C. These alloys are used as temperature sensors in fire detectors and automatic sprinkler systems because, in case of... 

Fire testing used to develop automatic sprinkler system design criteria has shown that other factors are important to determine the overall fire hazard of containerized liquids. These factors include the liquid properties, such as liquid burning rate, fire point, specific gravity, water solubility, and viscosity, as well as the container design and size. These important factors have been incorporated into the sprinkler system design tables in Section 4-8 of the 1996 edition of NFPA 30. 

Means of egress criteria may also rely upon the presence of other building features in the chemical warehouse. Examples include automatic sprinkler systems, fire detection/warning systems (optical flamesensing, smoke, heat, etc.) and smoke removal systems. In certain situations, these systems may permit less restrictive arrangements of the means of egress components. 

Bismuth alloyed with tin or cadmium is used as a low melting alloy in automatic sprinkler systems for fire prevention. A typical alloy contains 30% Bi. If an 0.80 g sample is dissolved in 50 mL of acid and a chelate formed, how many extractions employing 20.0 mL of benzene will be required to reduce the Bi concentration to... 

Costs in Safety. The hazards present are a direct function of the fire insurance rates that can be obtained. A decrease of the hazards may effect important savings in the insurance items of the overhead costs. In this connection, the cost of a complete automatic sprinkler system may be entirely defrayed by the resulting decrease in fire insurance rates. Such protective schemes and equipment are not so easily paid for, but they frequently can be justified on economic grounds alone. Hazards also involve loss of production and men .s. services as well as impairment of product quality. Reduction of hazards thus becomes an economic problem. 

NFPA 30, 4.4.3.S NFPA 30, 4.5.14 NFPA 30, 4.5.2.S 4.3.2 Class Iflammable liquids (see definition) shall not be stored in basement areas. Class II and Class IIIA combustible liquids (see definition) shall not be stored in basement areas imless those areas are protected with automatic sprinkler systems. 

Wood s motal Alow-melting (71°C) alloy of bismuth (50%), lead (25%), tin (12.5%), and cadmium (12.5%). It is used for fusible links in automatic sprinkler systems. The melting point can be changed by varying the... 

The B6580/81 automatic sprinkler system also sen/es the HCF. Standard spray automatic sprinklers are provided in occupied areas of the basement, including Rooms 100,104,105,106, 107, 111, 112,113,113Aand114. The HCF is equipped with an independent fire-alarm control panel, located against the south end of the west wall of Room 107 that monitors all areas of the HCF. Water that may be released during fires is captured and routed to holding tanks. This capture system is described in Section 2.9.5. Any sprinkler-water flow will activate the TA-V... 

References for this study included in Automatic Sprinkler Systems Handbook (3d edition), edited by John K. Bunchard and published by the National Fire Protection Association (NFPA) (1987) and Automatic Sprinkler and Standpipe Systems, by John C. Bryan, also published by NFPA (1976). Probability data was interpolated from NFPA and other studies as reported in these publications. (Note As previously noted, probability/relia-bility data in this example are for illustrative purposes only and may not be accurate.)... 

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