July 08, 2022

The Importance of Internal Obstruction Testing and Regular Flow Tests

Importance of Internal Obstruction Testing

As per NFPA 25, an internal inspection of fire sprinkler system piping is required every five years. The purpose of this inspection is to confirm the presence of foreign organic and inorganic materials. Any and all foreign materials or years of sediment build-up can cause major obstructions to water flow and ultimate sprinkler head operation or failure.

Testing and maintaining a commercial fire sprinkler system is not only a mandatory function but also an essential one for life safety. Being that the internal diameter of the sprinkler pipe from the water supply source to a sprinkler head is not less than 3/4 of an inch (20 mm) and the adapter fittings from where sprinklers are attached to the piping are not less than 1 /2 inch (15 mm) in diameter readily enables any debris to become trapped within the pipe and may cause a serious problem during a real fire situation. The most common substance that causes obstructions is calcium carbonate or corrosion that comes from the public water supply.
As per NFPA 25 (Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems) Section mandates an assessment of the internal condition of the piping every 5 years in order to detect the presence of any corrosive or foreign materials to prevent optimal function.

An in-depth look at piping will determine if a deeper investigation is required. Some areas will necessitate a more frequent inspection such as pipes in dry or preaction systems. The tests look for pooling water, (where trace water is left after an activation) that would make the piping system more susceptible to corrosion.

Non-metallic pipes are an alternative because they are corrosion-resistant, however, these pipes can also have clogs and debris running through them that can cause obstructions and blockages.
Many obstructions can be prevented outside routine testing by looking for the following signs:
  • Any foreign material discharged during a test
  • Foreign matter in any check valves, pipe valves, or fire pumps
  • Unknown material detected in the system pipes
  • Plugged sprinklers
  • A failure to flush following repairs or a new installation
  • A record of any broken mains in the area
  • Frequent false tripping of dry pipe valves
  • Raw water sources from the fire department connection
  • The detection of any visual leaks
  • Reduced time water travels to the inspectors' test connection from a dry pipe valve during a full-flow trip test
Other indicators to look for would be the presence of rust, any black or off-colored water, or the smell of sulfur should prompt a deeper investigation.

The presence of bio-film also should raise a red flag as microorganisms within the pipes can cause obstructions and blockages as well.

Multiple factors can be attributed to failure and fire loss from improperly maintained fire sprinklers and water systems. Taking into consideration inefficient installation; previous repairs; pipe scale; raw water sources; ice plugs; and calcium carbonate deposits -various factors contribute to the need for thorough and frequent inspections to mitigate fire loss.
As a property owner, taking a proactive approach is best to keep your fire sprinkler systems in top working order. Here are the dates to remember: 5-3-1 and Extra
  • 5 = NFPA 25's 5-year internal inspections of pipe (Section
  • 3 = The three-year checks on dry and preaction systems (Section
  • 1= Annually assessing a sample of sprinklers where hard water is an issue ( Section 0.4.5)
  • Extra= Any additional investigations for when certain conditions are observed (Section 14.3.1)

About Allstate Sprinkler

Our family business has developed from a ''mom and pop" company into a highly regarded fire protection contractor servicing the New York City Metropolitan area. Our commitment is to assist you with all of your commercial and residential fire protection needs. We have built a reputation on the sound principle of providing professional service and high-quality products to all our customers. Our services include but are not limited to the following: complete installations and alterations of fire sprinkler and standpipe systems, prompt correction of all fire department violations, five-year hydrostatic pressure tests, emergency service, and repairs, fire pump testing and installations, fire extinguisher sales, and service, and all fire safety products and equipment.

Allstate Sprinkler, LLC is a licensed Master Fire sprinkler contractor with the New York City building department. Providing our customers with cost-effective, professional, and reliable service is our priority. We hope that you will enjoy our website and become a part of our family customer base.
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