What is one of the substances used for the protection of CPVC sprinkler systems?

Glycerin is commonly utilized in the protection of CPVC (Chlorinated Polyvinyl Chloride) sprinkler systems due to its characteristics that safeguard the material from degradation. CPVC is sensitive to certain chemicals, particularly those that can lead to stress cracks or compromise its integrity. Glycerin serves as a more compatible option because it does not interact adversely with CPVC and can help to maintain the operational functionality of the sprinkler system in various environmental conditions. This compatibility is particularly critical in preventing corrosion and ensuring a longer life span for the sprinkler components.

Other substances, while potentially useful in other applications, are not generally recommended for use with CPVC due to their potential to cause damage or degradation.