Research

The engineers at fpsCMI have completed research and published white papers on the following fire protection system corrosion topics.  If you would like to obtain a copy of a complete white paper or discuss the topics below please call or email us for more information.

Fire Protection Systems Corrosion Management, Inc.
2043 Woodland Parkway
St. Louis, Missouri  63146
Office (314) 432-1377
Fax (314) 439-9411
Toll Free (877) 432-8040
Email:  info@fpscmi.com

White Paper Topic #1: Fire Protection System Corrosion Inhibitors:

Chemical corrosion inhibitors function by limiting the interaction of the corrosive fluid with the subject metal.  They do this by first migrating to the water/metal interface where they form a barrier that inhibits the cathodic reaction.  That is the half of the corrosion reaction where the corrosive fluid creates a demand for electrons that are satisfied when the subject metal gives up those electrons to become a water soluble ion.  In effect, that is what corrosion is, when a metal gives up its electrons and dissolves in to the water leaving a void in the metal surface. Email for this topic

White Paper Topic #2: Using Galvanized Steel Piping in Dry and Preaction Fire
Protection Systems:

The use of galvanized piping has been proposed as a remedy for controlling corrosion in dry and preaction fire protection systems.  Although there are several different galvanization methods, the end result is that alloyed layers of zinc are applied to the base metal which is mild steel.  Dry and preaction fire sprinkler systems always contain some amount of trapped water.  In the persistently moist, oxygenated environment that exists inside the piping, zinc DOES NOT provide adequate protection to prevent premature failure due to corrosive attack. Email for this topic

White Paper Topic #3: Using Nitrogen Gas in Dry and Preaction Fire Sprinkler Systems:

In order to prevent the corrosive effects of oxygen in dry and preaction fire protection systems, nitrogen can be used as the pressurizing gas in place of compressed air.  When nitrogen is added as the pressurizing gas to “dry pipe” systems containing air at atmospheric pressure, the concentration of nitrogen gradually increases as the pressure increases.  Compressed air contains 78% nitrogen, 21% oxygen and 1% other trace gases.  However, in order to achieve corrosion control, the fire sprinkler system piping must be vented during nitrogen addition to remove the oxygen that was initially present when air filled the pipes.   The objective is to ultimately achieve an atmosphere in the pipe that is 95%+ nitrogen gas. Email for this topic

White Paper Topic #4: Using Nitrogen Gas to Remove Corrosive Gases in Fire Sprinkler Water:

By continuing to increase the percentage of nitrogen in the fire sprinkler system, oxygen can actually be stripped out of the water. When this is accomplished, the oxygen is no longer available to corrode the metal surfaces of the pipe. This phenomenon is at the heart of the process of using nitrogen gas to control corrosion in fire sprinkler systems. This approach to corrosion control works in both residual amounts of water that are trapped in dry pipe fire sprinkler systems and with water contained in wet pipe fire sprinkler systems   Email for this topic

White Paper Topic #5: Atmospheric Corrosion of Malleable Cast Iron Fittings Used in Wet Fire Sprinkler Systems:

When wet fire sprinkler systems are put into service the pipes are filled with water and pressurized to allow for instant delivery of water from the sprinklers in the event of a fire.  In many installations, like warehouses and garages, fire sprinkler piping is exposed to unconditioned ambient air and is subject to the normal temperature fluctuations that occur during seasonal weather changes.  Whenever the temperature of the ambient air is warmer than the temperature of the water in the fire sprinkler piping, there is a chance that water can condense on the outside surface of the pipe.  Malleable cast iron fittings that are typically used during construction of wet fire sprinkler system have no protective coating and the iron in the fittings is readily available to react with any water that condenses on the surface of the fitting.   Email for this topic

White Paper Topic #6: MIC is NOT the Primary Cause of Corrosion in Fire Sprinkler Systems:

The simple fact is that the primary cause of internal corrosion (metal loss) in fire sprinkler systems is oxygen attack of the iron and zinc (in the case of galvanized pipe) that are used to fabricate fire sprinkler system piping. While it is true that microbiologically influenced corrosion (MIC) is often a contributing factor to the overall corrosion picture, it is not the primary cause of the internal corrosion.  Moreover, the solids that are produced by the action of oxygen on the metal piping actually produce conditions that favor the proliferation of bacteria in the system.  Email for this topic

White Paper Topic #7: Mission Critical Facilities - Is the Use of Galvanized Pipe an Effective Corrosion Control Strategy in Double Interlock Preaction Fire Protection Systems?

There is now a significant body of evidence that suggests that the use of galvanized steel pipe in dry and preaction fire sprinkler systems may expose mission critical facility owners to the risk of premature system failure due to internal corrosion. Conditions that typically exist within dry and preaction fire sprinkler system piping create an environment in which zinc coated mild steel will corrode, sometimes quite aggressively. In the case of mission critical facilities, the risks of premature failure are more pronounced than they might otherwise be because of the sensitivity and costs of the systems that are being protected. A water leak simply cannot be tolerated. Email for the topic