From concept to completion: Telgian reveals the 10 steps to sprinkler approval
Iain Hoey
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Jacob Ford, Fire Sprinkler Design Team Lead at Telgian Engineering and Consulting, outlines the essential stages of system design and regulatory approval
Fire is a powerful force of nature that can be detrimental to buildings and even entire cities. To create a safer, more effective society, there must be a way to control or limit the potential danger posed by fire. That is where fire protection engineering, and one of its subdisciplines, fire sprinkler design, come into play.
Fire engineering is a diverse field that draws on many engineering disciplines. This field encompasses a broad range of pursuits, all with the common goal of minimising or preventing fire damage, achieved through various fire prevention and protection methods. Although these two concepts may sound redundant, they each offer their own distinct advantages toward the overall goal of fire control.
Fire prevention vs. fire protection
Fire prevention encompasses various strategies to prevent fires from starting in the first place, including: Risk analysis; Human behaviour in fire events; Building design layout; Programs and procedures for fire events.
Fire Protection involves systems that are put in place to protect life and property in the event of a fire. These systems can be either active or passive. Examples of active fire protection systems: Fire sprinkler systems and fire alarm systems. Fire sprinkler and alarm systems activate in the event of a fire and provide a means of assisting in controlling the fire or warning of its presence.
Examples of passive fire protection systems: Smoke control (smoke barriers, separation); Coatings and casings; Fire-retardant building materials (fire walls, fire doors).
The role of fire sprinkler design
Fire sprinkler systems are the most common form of fire protection. For these systems to be installed and effectively protect against fire, they have to be designed to a predetermined standard. That is where the fire sprinkler designer comes in.
Fire sprinkler designers utilise many fields of engineering, including:
- Electrical: Electrical design fundamentals will be used when the designer coordinates integration with the fire alarm system or when coordinating power supply requirements for fire pump selection and design.
- Mechanical/Piping: Mechanical and piping layout skills are used to create the fire sprinkler piping system and to coordinate with elements of other disciplines.
- Fluid Dynamics/Hydraulics: The designer demonstrates knowledge of fluid dynamics and hydraulics by designing the system in a hydraulically efficient manner and validating it through hydraulic calculations.
- Structural: A fire sprinkler designer must understand structural elements and how buildings are constructed. This knowledge is crucial for routing the system, as some architectural elements cannot be covered or hidden, and piping can only be hung from certain structural members.
- Civil: A basic understanding of civil engineering is required for tasks such as fire hydrant placement, soil classifications to determine the need for seismic bracing, and thrust block calculations for underground pipes.
Key design considerations
When a designer begins a project, they must consider the following factors.
Building layout: Certain architectural and structural elements may limit the placement of system components; Building size will determine the number of systems needed to protect it; and portions of the building that are not conditioned or exposed to the elements may warrant the inclusion of dry or pre-action systems.
Building occupancy and use: Different occupancies correspond to varying levels of risk and potential fire severity. The designer will select the type of system that best protects the hazard with minimal risk. For example, the designer should choose a pre-action system for a data center to minimise the potential for pipes to leak onto the servers. This system fills the pipes with air unless there is a fire event.
Local codes and standards: Although there are national standards for the design of fire sprinkler systems, various AHJs (authorities having jurisdiction) have the choice to adopt past iterations of these standards, which can vary in their requirements, and alter and amend sections of the code for their region.
Geographic area: The location of a facility determines the need for seismic bracing on the sprinkler system if it is in an area subject to earthquakes. Also, local weather may necessitate a dry sprinkler system.
Steps in the fire sprinkler design process
During the design phase of a project, the sprinkler designer will go through several steps as outlined below.
- Consult with the building owner/client.
Coordinating with the building owner/client is crucial to the design process, as this is where the scope of work is determined. The owner may be able to move some storage out of their building to avoid a sprinkler system upgrade, or they may want to strengthen what they already have in anticipation of the building’s occupancy changing in the future.
- Analyse the water supply.
This is typically done by performing a fire hydrant flow test as outlined in NFPA 291. During a flow test, the person performing the test opens a fire hydrant and measures the resulting water flow. They place a gauge onto another hydrant to measure both static (no flow) pressure and residual (flowing) pressure. The designer sometimes performs this test, but it may be done by others.
- Determine applicable codes and standards.
The designer, or in some cases a consultant, coordinates with the AHJ to determine what codes and standards apply to the project’s location.
- Identify the hazard or commodity.
The commodity being protected will be a factor in determining the system type and the correct density for hydraulic calculations.
- Identify the sprinkler system type.
Based on the previous steps, the designer should have enough information to determine the best type of sprinkler system to protect the building(s).
- Lay out the sprinklers and system piping.
The design layout must follow NFPA 13, manufacturers’ data sheets, and any local codes or amendments. Based on the sprinkler layout, the designer will then lay out the system piping, making sure to connect the heads to each other via the piping and routing around obstacles in the most hydraulically efficient manner.
- Perform the hydraulic calculations.
The designer must verify the system layout with hydraulic calculations utilising the water source determined during the water supply analysis phase. The designer will calculate the most hydraulically demanding area of the system to a predetermined density (volume of water over area) that has been decided upon (typically derived from code) based on the hazard. The results of these calculations will determine if the water supply is adequate to support the system. If the supply is insufficient, the designer can upsize the piping or add a water tank/fire pump. A fire pump will aid the water supply if a lack of pressure is the issue, and a tank will supply water if volume is the issue.
- Obtain AHJ approval of the designs.
The fire sprinkler system design needs to be reviewed and approved by the local authority having jurisdiction.
- Prepare for system installation.
The designer will then move to stock listing, which is the process of selecting the materials required for fabrication based on the design plans. Based on this list of materials, the designer will order the correct components, then the system will be fabricated and installed.
- Await system inspection and final approval.
The AHJ performs an inspection following the system installation. The designer is typically involved during this phase directly through design and/or indirectly through answering questions and being a resource for those performing the inspection.
Fire sprinkler design field
The role of the fire sprinkler designer is instrumental throughout the process of developing a fire sprinkler system, making it an invaluable and much-needed role in the fire protection engineering field. Designers can find careers with engineering firms, fire sprinkler contractors, and property insurance companies.
As long as buildings are being built, there will be a need for fire sprinkler designers, making it a stable and future-proof profession.
About the Author
Jacob Ford, Fire Sprinkler Design Team Lead at Telgian Engineering and Consulting, has been in the fire sprinkler industry for 19 plus years. He is NICET certified in Water Based Systems Layout and has worked on a wide variety of projects ranging from foam systems, clean agent, aircraft hangers, hospitals, gamma knife facility, clean rooms, large data centers, sports training facilities, etc. Starting his career as an apprentice pipefitter and moving to a designer role shortly after college, Jacob is a demonstrated leader in the fire protection field having held several leadership, training, consulting, and management roles in both the contracting and engineering sectors of fire protection.