How to Repair Fire Sprinkler system Obstructions

There are many objects and materials that can cause fire sprinkler system obstructions. Here are several to watch out for.

1. Corrosion

Corrosion is the deterioration of a material due to a chemical reaction. And, unfortunately, the presence of metal, water, and oxygen in fire sprinkler systems make corrosion inevitable. In fact, most piping systems contain some traces of it — it’s just usually not enough to pose a risk for obstruction. But when the level of corrosion does get too high, obstruction is more likely.??

The most common types of corrosion that cause fire sprinkler systems obstructions are:

• Rust - Iron oxide corrosion
• Microbiologically influenced corrosion (MIC), which is the presence and/or activity of microorganisms (e.g., bacteria, fungi) in biofilms on the corroding material.
• ?Galvanic corrosion, which is when two or more dissimilar metals are in electrical contact under water.

2. Foreign Materials from Poorly Filtered Water Sources

If your fire sprinkler system uses water from unfiltered or poorly filtered sources, it may be at risk for a foreign material obstruction (sand, pebbles, etc.) and or biological growth that feed on bacteria or algae. Ideally, you would want to supply your fire sprinkler system with filtered and chlorinated water. If that is not possible, make sure the water is tested and treated regularly.

3. Calcium Carbonate Deposits

Especially in Texas, when the concentration of calcium and magnesium salt is high, the water in your fire sprinkler system can get hard. Hard water creates a thin film of calcium carbonate, which can block sprinkler openings. These obstructions are most common with fire sprinkler systems that source water from non-potable wells or areas that are known to have hard water.

Remedies and Prevention

Be proactive. Follow the National Fire Protection Association’s (NFPA’s) testing and inspection requirements, and know what issues to look out for so you can identify obstructions in their early stages and resolve any problems before they cause too much damage.

Complete Routine Fire Sprinkler System Obstruction Inspections Required by NFPA 25For water-based fire sprinkler systems, NFPA 25 requires an inspection of the internal condition of piping every five years. If there is minimal obstruction-causing material found, that’s where the inspection ends. However, if a sufficient volume or type of a certain material is found, a more in-depth investigation is required to understand the cause of the obstruction and to fix it.?

For dry and pre-action systems, an inspection of the internal condition of piping is required every three years during the regular full-flow trip test. The higher inspection frequency is due to the higher tendency for corrosion in dry and pre-action systems. Call on the professionals at Cherokey Fire Protection for an inspection of your fire sprinkler system.