On-Site System Assessment/Inspection
In order to determine the extent of corrosion damage that has occurred on the internal pipe walls in fire sprinkler systems, ECS offers the Fire Sprinkler System Corrosion Assessment Program. This process is used to determine the root cause of the corrosion, the locations within the piping where damage has occurred and the severity of the damage. In most cases, even with systems that are 10 years old and older, it is not necessary that the entire fire sprinkler systems be replaced. Remediation of the system with limited pipe replacement and the implementation of a comprehensive corrosion control strategy can save most systems.
The activities that will support the assessment include the following:
- Review of system as-built drawings, if available
- Identification of “hot spots” within the system where failures have occurred in the past
- Identification of most likely locations for accelerated rates of corrosion (trapped air in wet pipe systems, trapped water in dry pipe systems, higher temperatures, likely locations for solids build-up)
- Interview of maintenance staff who have knowledge of the system history (location of failures, repairs that have been performed on the system and any system problems)
- Fire sprinkler system activity (drain and fill history, test frequency)
- Defining the corrosion mechanisms and “root causes” for the metal loss, pit formation and leak development
- Outline possible corrosion control strategy that addresses the key corrosion mechanisms (materials selection and treatment options)
- Development of a remediation and pipe replacement plan based on findings
- Recommendation of complete corrosion control strategy going forward for the system with associated system modifications, corrosion device needs and expected program costs
- Recommendation for complete in-situ corrosion monitoring strategy
Assessment Program Investigative Tools (ranked by importance)
- Video scoping of the internal piping – this is the most valuable investigative tool because it provides physical inspection evidence of the internal piping. Corrosion is always associated with solids. Visual evidence of solids and metal loss is the most important physical evidence.
- Sectioning, cleaning and analyzing pipe samples from the system – this provides for thorough investigation of the actual metal loss that has occurred on the metal surface. Metal loss should be characterized by pit shape, size, depth, and frequency as well as texture of the metal loss, appearance of the surfaces under deposits and composition of the corrosion by-products.
- Determination of the type and degree of microbial contamination in the system – this provides a clearer definition of the type of organisms that contaminate the system which can lead to a much clearer understanding of the corrosion mechanisms. This also defines the extent of involvement of microbiologically influenced corrosion (MIC).
- Determination of the elemental composition of debris collected from inside the system – this is used to further define the corrosion by-products and the mechanisms that formed those by-products.
Once the risk profile and status of the existing fire sprinkler system has been determined using the assessment process and analytical tools, the ECS team pulls together all of the data to develop a comprehensive corrosion management strategy moving forward that is ideally suited for the unique attributes of your facility.
We strongly recommend that any facility with a dry pipe fire sprinkler system over 5 years old or a wet pipe fire sprinkler system over 10 years old should have an assessment performed. DO NOT WAIT FOR THE FIRST LEAK. If the assessment is performed before the pipe damage is too severe, a complete corrosion control program including the use of nitrogen gas to inert the system piping can save the system and reduce the leak risk going forward.