Protecting Sprinkler Valves

The wet pipe system. This is the most prevalent type of sprinkler system used  

There are several disadvantages to dry pipe systems that should be noted  

The deluge system. This system releases a water spray from the sprinkler heads. A deluge valve is activated by heat detectors mounted above the sprinkler heads. There is nothing within the system to hold back the water. This system could be used in a warehouse that stores drums of flammable liquids. 

Like the dry sprinkler system, the deluge system has several disadvantages  

The preaction system. In libraries, museums, or other locations where special contents may be housed, the preaction sprinkler system must be used. Any operation of the sprinkler system in the absence of fire would be devastating to the building contents. Most fire safety professionals identify two events that must take place in order to activate the system. First, the heat of a fire will melt the fusible link in the sealed sprinkler heads. Second, a detector must open the deluge valve to admit the water. In the absence of either of these two events, the sprinkler system will not function. The biggest disadvantage of this system is the cost. However, when contents of great value must be protected, the expense of a preaction system may not be restrictive. 

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Are protection (closes windows or opens sprinkler valves) and... 

Lift shafts could easily transmit fire and smoke and these are covered in eodes. Certain equipment such as sprinkler valves must be fire-isolated. Openings in external walls and fire walls reqniie protection. 

One special security control mentioned several times in the literature is the locking of all sprinkler control valves in the open position. Many times, arsonists will render or attempt to render the fire protection systems ineffective by sabotaging the automatic sprinkler system (NFPA 921, 2011). The locking of all sprinkler valves will help to ensure that the sprinkler system has a water supply and will be effective during a fire. 

Sprinkler valve closing Shutdown of fire protection system by closing fire main or sprinkler system (note this may be covered by local fire or insurance company regulations). 

Trained fire protection engineers must determine the type of system to install in a warehouse and must also design and supervise the correct installation of the system. The four basic sprinkler systems listed below can be installed individually or in combination with each other Figure 5-4. Sprinkler valves are protected by this barrier made of... 

The next step is to apply a number of loss control credit factors such as process control (emergency power, cooling, explosion control, emergency shutdown, computer control, inert gas, operating procedures, reactive chemical reviews), material isolation (remote control valves, blowdown, drainage, interlocks) and fire protection (leak detection, buried tanks, fire water supply, sprinkler systems, water curtains, foam, cable protection). The credit factors are combined and appHed to the fire and explosion index value to result in a net index. 

The local fire department arrivedjust after the explosion at 11 22 A.M. With the limited water supply on two of the fire trucks and the utilization of another fire truck to pump water directly from a nearby cooling water tower basin, the firemen were able to slow the fire spread. By 11 30 A.M., the Maintenance Department was able to transfer the set of batteries from the impaired diesel fire pump to the other diesel fire pump. On completion of this task, this diesel fire pump was started. The automatic deluge sprinkler protection was severely damaged by the fire/explosions and had to be valved into the off position. Three fixed monitors were turned onto lull flow and directed at the fire. Also, the firemen and fire brigade used two hose streams olF nearby fire hydrants for fire fighting purposes. At 11 58 A.M., the fire was under control. Final fire extinguishment was accomplished by 12 10 p.m. 

Preaction Systems This is a special fonii of dry-pipe system. The piping may or may notbe under pressure. There are sensors in protected areas besides sensors at each sprinkler head. The special sensors detect a fire and open a valve to fiU the pipe with water. The special sensors operate before those in the sprinkler heads. This design reduces the delay found in a dry-pipe system. 

The System 80+ Standard Design is designed to preclude water spray from the fire protection system onto safety-related equipment. The sprinkler systems protecting the safety-related equipment is of the automatic sprinkler type. Actuation of these sprinkler systems requires the opening of the fusible link sprinkler heads and detection by combustible-products and/or heat detectors. In addition, the operator has the capability of isolating flow from the control room by isolating the Sub-sphere Building headers or, locally by manual isolation valves. 

The applicable codes and standards provide criteria for external inspections for such items as foundation and supports, anchor bolts, concrete or steel supports, guy wires, nozzles and sprinklers, pipe hangers, grounding connections, protective coatings and insulation, and external metal surfaces of piping and vessels, etc. These codes and standards also provide information on methodologies for internal inspection, and a frequency formula based on the corrosion rate of the materials of construction. Also, erosion both internal and external needs to be considered along with corrosion effects for piping and valves. Where... 

Diversion of flow safely All the above systems discussed are part of electronic system requiring power. As a next layer of protection there are mechanical devices (requiring no power to meet power failure situations) to divert the flow safely. Safety and relief valves are used to in case to depressurize when SIS fails to take care (e.g., say due to control power failure). Pressure relief valve diverts the fluid for safe passage. These relief valves are spring force to close so that when pressure is below setting it is closed. Many cases rupture discs are used but in that case system needs to be closed to attain the disc. To a certain extent quartz bulb in sprinkler system does the same function. 

An analysis in 1977 of all Factory Mutual incendiary losses over 100,000 showed that the primary factors contributing to the extent of the loss were the lack of automatic sprinklers and closed sprinkler conti ol valves (p. 14). These were valves not closed by the arsonist. This study further states that valve supervision is one of the most important forms of protection against incendiary losses (1977, p. 14). Even in those buildings that are equipped with sprinklers, incendiary fires can be devastating if the owners do not regularly maintain and inspect their fire protection systems. Therefore, regular inspections by the building owner, as well as strict code enforcement, should control this problem. 

Fire Protection and Emergency Response Equipment Alarms, water tanks, sprinklers, standpipes, hydrants, hoses, self-contained breathing apparatus, automatic valves, horns, phones, radios. 

Where subject to temperatures below 40°F (5°C), a wet-pipe system cannot be used.There are two recognized methods of maintaining automatic sprinkler protection in such locations (1) through the use of systems where water enters the sprinkler piping only after operation of a control valve... 

NFPA 25, Inspection, Testing and Maintenance of Water Based Fire Protection Systems, provides requirements and procedures for ensuring that the systems discussed in the section will perform as intended. The standard provides requirements for proper inspection, test, and maintenance procedures for sprinkler, standpipe, and underground supply systems, as well as fire pumps, water storage tanks, spray systems, and foam-water sprinkler systems. Other chapters address record retention provisions, valve inspection procedures, and system impairment procedures. 

Chemical dispensing areas can be protected with automatic sprinklers. The room should have sprinklers on an extra hazard density. They should be 286°F heads and have separate control valves. 

Active fire protection Active fire-protection system Periodic inspection of valves and fire-fighting equipment Periodic testing of fire pumps, sprinkler systems and foam skids... 

A sprinkler system can be one of the most important fire-fighting items in any facility. If a fire starts, the sprinkler system must work effectively. The fire must be detected early and the system must deliver the proper amount of water to properly extinguish the fire. To be effective, sprinkler controls must be protected from lift truck damage. The most common cause of automatic sprinkler failure is that the water valve was turned off. The control valves in Figure 5-4 illustrates the protection provided by racking. 

Sprinklers are necessary for the protection of property and employees in a warehouse. Valves, sprinkler heads, gauges, and pipes must be protected firom damage caused by powered equipment. A survey should be made of the facility to determine where these safeguards are needed. 

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