sprinklernotes Piping Exposed to Outside Elements
You asked the following question: “NFPA 13, Section 8.16.4.2.3 requires pipe, fittings, and hangers that are “exposed to the weather” to have a corrosion-resistant coating. What is the definition of “exposed to the weather”? For instance, must it be within an environmentally controlled or conditioned portion of the building?” In response to your question, we have reviewed NFPA 13, 2016 edition as the applicable standard. Our informal interpretation is that exposed to the weather is not defined by being outside a conditioned portion of the building. Section 8.16.4.2 covers the issue of protecting the system against corrosion. There are two related and very similar requirements. One is 8.16.4.2.1* that states: Where corrosive conditions are known to exist due to moisture or fumes. The other is 8.16.4.2.3 that states: Where corrosive conditions exist or piping is exposed to the weather, corrosion-resistant types of pipe, fittings, and hangers or protective corrosion-resistant coatings shall be used. I mention the first one because there is annex material linked to it that clarifies the intent for both sections. This is A.8.16.4.2.1 where the first sentence is: Being exposed to the outside atmosphere is not necessarily a corrosive environment. This text used a vague “is not necessarily” instead of the all-inclusive “is not” since there are limited conditions, such as being near the coast, where simply being exposed to the outside environment is considered corrosive. Even in coastal areas, an enclosed warehouse that is not environmentally controlled (or conditioned) is not considered a corrosive environment. Away from the salty air, as long as the system has a roof above it (like a canopy or a covered loading dock), it is exposed to the outside atmosphere but IT is not a corrosive environment. The reference to “exposed to the weather” is when the system is directly exposed (uncovered) and being rained on. As a side note, the first section does not use the phrase “exposed to the weather” since there are conditions within an enclosed building, such as swimming pools and operational activities, that presents a corrosive environment.
