Sprinkler system basics

Sprinkler system design and construction are paramount to fire suppression and safety in all industrial facilities. They have more significance within the waste, recycling and scrap metal industries as material types are various, less controlled and often create their own heat source (spontaneously combust). These industries in particular are susceptible to fire arising from processing material. The material is diverse by nature, and these facilities do not have the infeed standardization and controls that characterize typical manufacturing or raw materials processing facilities.

Also troubling is that, more often than not, fire suppression can be overlooked by or be an afterthought for these industries.

We work with some operators who are spending money and time designing responsive fire-suppression systems, but most operators who we see do not.

Systems can be designed to handle the most challenging of environments, resulting in limited loss instead of complete loss. While this is anecdotal, a plastics recycling customer in the Midwest operates a 300,000-square-foot facility that grinds postindustrial plastics. The sprinkler system was designed in the early 2000s with input from an insurance company loss-control engineer, sprinkler engineer and local officials. CIA received a call in April 2018 from the company’s chief financial officer (CFO) who said the facility had a fire. Because of the plastic content and fire load of the facility, I expected the worst, as did the CFO. The next morning, the CFO called me back to let me know that the sprinkler system worked as designed, suppressing the fire until the fire department showed up and put a hole in the roof of the facility to fully extinguish the fire. The postfire inspection showed that the fire started in a shredder, and two sprinkler heads went off to suppress the fire. The total amount of the loss was less than my client’s $150,000 deductible. After the fire, the client assessed the situation and installed foam sprinkler systems into the five plastics shredders in its facility to ensure future losses were less significant than the small loss it had experienced.

Most of the facilities that we tour as insurance agents do not have fire suppression systems at all let alone those that are as sophisticated as the plastic recycler’s system. Had a lesser system been in place at this client’s location, the loss would have been much more significant. Had no system been in place, the fire could have resulted in a total loss, necessitating a new building, new equipment and two-plus years of lost income. The investment in a sprinkler system kept this recycling business running with limited downtime.

In the details

While fire suppression is paramount to facility preservation and safety, the details of building such a system often are overlooked.

For example, CIA has a prospective customer who purchased a 200,000-square-foot facility previously used as a secondary aluminum smelter. Because of the previous use of the building (hot aluminum and water do not go together), neither a fire suppression system nor rate-of-rise detection system was in place. The prospect invested more than $30 million in wire chopping equipment and installed it in the building. When CIA got involved, loss engineering went poorly. We advised the prospective customer to invest hundreds of thousands of dollars in retrofitting the building and installing a proper fire-suppression system. Most insurance companies would not insure the building because of the lack of fire protection, and the prospect was forced to buy a costly excess and surplus lines policy. This could have been avoided if the prospective client had thought about fire suppression as part of the building retrofit, allowing the company to budget for the processing equipment and sprinkler system simultaneously.

Fire-suppression systems, especially in waste, recycling and scrap metal facilities, need to be bespoke, or tailored to the facility. Facility owners and managers need to work with a series of people, including local inspectors, sprinkler engineers and insurance loss-control engineers, to design systems that can deal with the fire load and height of the stacked inventory. Again, unlike in a manufacturing facility, these demands can vary widely.

Consult a loss engineer

We encourage our clients to work with an insurance company loss engineer or CIA’s own consultant to design a fire-suppression system. Typically, local ordinances overlook building use and fire load and instead are only concerned with local codes. Systems designed in this fashion might not be considered fully sprinkled or sprinkled at all by an insurance professional.

Insurance companies and our own loss engineer use National Fire Protection Association (NFPA) guidelines to determine viability and performance of any fire-protection system. NFPA is a nonprofit with a mission “to help save lives and reduce loss with information, knowledge and passion.” The organization “delivers information and knowledge through more than 300 consensus codes and standards, research, training, education, outreach and advocacy.” NFPA, through its research, has crafted codes specific to occupancy, fire load and material type. These codes should be followed to design a system with proper sprinkler density and water pressure.

The waste, recycling and scrap metal industries require higher demands from sprinkler systems. Based upon fire load and material, often these demands can be two times the demands of a system required by local codes. Only part of a processing facility could necessitate these demands, and properly qualified engineers can design segmented systems to help recycling and waste companies manage costs.

Sprinkler system misconceptions

One of the biggest misconceptions of sprinkler systems is that all the heads go off at the same time. This is probably driven by movies and television shows. While some systems have deluge capability (triggered by detection systems), most sprinklers systems are more specific in the way they work.

Sprinkler heads have fusible elements (plastic, soft metal) that melt when temperatures reach a specific point. Only heads where the fusible element melts release water, concentrating the water flow where it is needed and limiting potential water damage to the area of concern.

Fusible materials have a range of typical melting points:

1. ordinary (125 to 170 F);

2. intermediate (170 to 225 F); or

3. high (150 to 300 F).

These temperature factors are an enormous part of system design and depend on the design method and the water supply provided.

System types also vary, depending on need and environment. The most common systems are wet systems, with water precharged into the system. That means there is no delay from when the fusible element melts, allowing the head to release water immediately. These systems are used in HVAC-controlled facilities and in unconditioned locations where the temperature never drops below freezing. Dry systems, on the other hand, are charged with air, which causes a delay in the release of water. The system does not fill with water until the fusible material melts, indicating demand. These systems are used in unconditioned spaces where the temperature can drop below freezing. They also are used in situations, such as around highly valued equipment, where sprinkler leaks could cause property damage.

Other factors should be taken into consideration when designing fire-suppression systems:

• Fire pumps are needed when city-provided water is not enough to support the system or to suppress the fire load of a given building.
• Fire towers are needed where city water is nonexistent or insufficient to support suppression.
• FM Global and NFPA guidelines stipulate sprinkler head size based upon the overall system design, material type and fire load.
• Sprinkler piping is based upon FM Global and NFPA guidelines and overall system design.

Ultimately, these systems are complex, and many factors must be considered to best protect a given property. When executed properly, sprinkler systems can suppress fires that occur in the waste, recycling and scrap metal industries, effectively limiting property damage and reducing risk to life.