Fire sprinkler

Fire sprinkler mounted on the ceiling
A fire sprinkler mounted on a ceiling

A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively used worldwide, with over 40 million sprinkler heads fitted each year. In buildings protected by properly designed and maintained fire sprinklers, over 99% of fires were controlled by fire sprinklers alone. [1] [2] [3]

History

In 1812, British inventor Sir William Congreve patented a manual sprinkler system using perforated pipes along the ceiling. When someone noticed a fire, a valve outside the building could be opened to send water through the pipes. [4] It was not until a short time later that, as a result of a large furniture factory that repeatedly burned down, Hiram Stevens Maxim was consulted on how to prevent a recurrence and invented the first automatic fire sprinkler. It would douse the areas that were on fire and report the fire to the fire station. Maxim was unable to sell the idea elsewhere, though when the patent expired, the idea was used. [5] [6][ clarification needed]

Henry S. Parmalee of New Haven, Connecticut created and installed the first automatic fire sprinkler system in 1874, using solder that melted in a fire to unplug holes in the otherwise sealed water pipes. He was the president of Mathusek Piano Works, and invented his sprinkler system in response to exorbitantly high insurance rates. Parmalee patented his idea and had great success with it in the U.S., calling his invention the "automatic fire extinguisher". [7] He then traveled to Europe to demonstrate his method to stop a building fire before total destruction.

Parmalee's invention did not get as much attention as he had planned, as most people could not afford to install a sprinkler system. Once he realized this, he turned his efforts to educating insurance companies about his system. He explained that the sprinkler system would reduce the loss ratio, and thus save money for the insurance companies. He knew that he could never succeed in obtaining contracts from the business owners to install his system unless he could ensure for them a reasonable return in the form of reduced premiums.

In this connection, he was able to enlist the interest of two men, who both had connections in the insurance industry. The first of was Major Hesketh, a cotton spinner in a large business in Bolton who was also Chairman of the Bolton Cotton Trades Mutual Insurance Company. The Directors of this Company and its Secretary, Peter Kevan, took an interest in Parmalee’s early experiments. Hesketh got Parmalee his first order for sprinkler installations in the cotton spinning mills of John Stones & Company, at Astley Bridge, Bolton. This was followed soon afterwards by an order from the Alexandra Mills, owned by John Butler of the same town.

An 1897 Grinnell automatic sprinkler advertisement

Although Parmalee got two sales through its efforts, the Bolton Cotton Trades Mutual Insurance Company was not a very big company outside of its local area. Parmalee needed a wider influence. He found this influence in James North Lane, the Manager of the Mutual Fire Insurance Corporation of Manchester. This company was founded in 1870 by the Textile Manufacturers' Associations of Lancashire and Yorkshire as a protest against high insurance rates. They had a policy of encouraging risk management and more particularly the use of the most up-to-date and scientific apparatus for extinguishing fires. Even though he put tremendous effort and time into educating the masses on his sprinkler system, by 1883 only about 10 factories were protected by the Parmalee sprinkler.

Back in the U.S., Frederick Grinnell, who was manufacturing the Parmalee sprinkler, designed the more effective Grinnell sprinkler. He increased sensitivity by removing the fusible joint from all contact with the water, and, by seating a valve in the center of a flexible diaphragm, he relieved the low-fusing soldered joint of the strain of water pressure. By this means, the valve seat was forced against the valve by the water pressure, producing a self-closing action. The greater the water pressure, the tighter the valve. The flexible diaphragm had a further and more important function. It caused the valve and its seat to move outwards simultaneously until the solder joint was completely severed. Grinnell got a patent for his version of the sprinkler system. He also took his invention to Europe, where it was a much bigger success than the Parmalee version. Eventually, the Parmalee system was withdrawn, opening the path for Grinnell and his invention. [8]