Ageing firefighting installations can cause severe reliability problems in historic buildings.
We publish the link to an interesting article (Corrosion Process Inside Steel Fire Sprinkler Piping, by Bruce W. Christ, Ph.D) published on the Fire Protection Engineering website, based on a review of the engineering and scientific literature pertaining to biological and nonbiological metal corrosion processes.
The review indicates that several metal corrosion processes can occur inside pressurized, water-based, metal fire sprinkler piping. The scientific literature of electrochemistry is rich with examples of corrosion processes other than MIC that can deteriorate metals. For example, “oxygen corrosion” is a nonbiological process that can corrode certain metals. Moreover, “acid-oxygen corrosion” is a nonbiological process that can corrode certain metals even faster than oxygen corrosion.
The article discusses also nonbiological corrosion processes that are spontaneous under the conditions of temperature and pressure that prevail in pressurized, water-based, metal fire sprinkler piping systems:
In 1963, the most famous painting in the world, the Leonardo da Vinci’s Monna Lisa, narrowly missed a catastrophe when it was on loan to the Metropolitan Museum of Art, after having left the Louvre in Paris for its first trip to the US. All possible precautions were taken for the painting’s safekeeping. It was transported across the Atlantic aboard the SS France in a waterproof crate designed to float if the luxury liner sank.
On 7 February, the portrait went on show at the Metropolitan Museum in New York to be seen by more than one million visitors in just a few weeks.
It was at the Metropolitan that the painting narrowly escaped severe damage one night, when a sprinkler malfunctioned, splashing water on the Mona Lisa for several hours.
In 1963, Dr Hoving (former director of the Metropolitan Museum) was a curator in the Metropolitan Museum’s medieval department. When he arrived at the museum before it opened one morning, he rushed to the secure storeroom where the painting was locked up at night, in order to check on an English 12th-century ivory cross he had recently purchased for the institution.
“I dashed to the [storeroom] to study my gorgeous acquisition, only to find that Murray Pease, the head of the conservation studio, and his assistant Kate Lefferts, [and] the officials from the Louvre in charge of the Leonardo portrait were rushing around with towels,” writes Dr Hoving.
“No one ever discovered why, but some time during the night one of the fire sprinklers in the ceiling broke its glass ampoule and the masterpiece of painting and the masterwork of ivory carving had both been…rained upon,” he adds.
Guards monitoring the Mona Lisa on a black-and-white monitor outside the storeroom could not see the water on their grainy screen.
“The Mona Lisa, according to the Louvre official, was ok…He told me that the thick glass covering it had acted like an effective…raincoat. The rainstorm was never mentioned to the outside world.” The Metropolitan Museum declined to comment on the incident.
Henry Gentle, a London-based private picture restorer, said damage to the painting could have been serious if it had not been protected by glass. “The paint could have swelled off [the panel] and become unstable. It really would have depended on the painting itself, whether it was protected by a strong varnish or not, and how long the water was dribbling on the surface.”
A malfunctioning sprinkler head reduced some historical documents kept in Columbia (USA) by the Missouri State Historical Society to waterlogged paper and soggy cardboard on October 1st, 2009.
Columbia firefighters arrived after receiving a report of a fire alarm sounding in the library and they have found the source of the alarm to be an activated sprinkler head in a storage room. The room was used to hold documents, in the lower level of the library.
Probably, it was some sort of mechanical failure in the head of the sprinkler system, which did cause water discharge. Firefighters shut off the sprinkler head and began cleaning the storage room. “In some cases, they may not be salvageable,” Executive Director Gary Kremer said.
Three shelves of books and documents were soaked. No one was in the room when the sprinkler head was triggered. “If the same system of sprinklers is throughout the facility, there are rooms — for example our art gallery — has tens of millions of dollars of artwork in it,” Mr Kremer said. “If the sprinklers were to malfunction there, that would be a catastrophe.”