Fire Protection 101
A straightforward guide to fire sprinkler systems and backflow preventers—what they are, how they work, and why they matter.
Fire Sprinkler Systems
Fire sprinkler systems are your building's first line of defense against fire. They're designed to detect and respond to fires automatically—often containing or extinguishing a fire before the fire department even arrives.
Wet Pipe Systems
The most common type of fire sprinkler system. Water is constantly held in the pipes under pressure, ready to discharge immediately when a sprinkler head is activated by heat.
Where You'll Find Them:
- Office buildings
- Retail stores
- Schools and universities
- Hotels and apartments
Key Point: Fast response time. Water flows as soon as a head activates—no delay.
Dry Pipe Systems
Instead of water, the pipes are filled with pressurized air or nitrogen. When a sprinkler activates, the air pressure drops, opening a valve that allows water to flow into the pipes and out through the activated head.
Where You'll Find Them:
- Unheated warehouses
- Parking garages
- Loading docks
- Freezer and cold storage areas
Key Point: Designed for spaces where water in the pipes would freeze. Slightly slower response than wet systems.
Pre-Action Systems
A hybrid system that requires two triggers before water is released: first, a detection system (like smoke detectors) must activate to fill the pipes, then a sprinkler head must open from heat. This two-step process prevents accidental discharge.
Where You'll Find Them:
- Data centers and server rooms
- Museums and archives
- Libraries with rare collections
- Telecommunications facilities
Key Point: Ideal where accidental water discharge would cause significant damage to sensitive equipment or materials.
Deluge Systems
All sprinkler heads are open (no heat-activated caps). When the system activates—typically through smoke or heat detection—water flows through all heads simultaneously, creating a "deluge" effect across the entire protected area.
Where You'll Find Them:
- Aircraft hangars
- Chemical storage facilities
- Power plants
- Industrial processing areas
Key Point: Maximum water coverage, fast. Used where fires can spread rapidly and need immediate, comprehensive response.
Common Sprinkler Head Types
Pendant Heads
Hang down from the ceiling. Most common type. Spray water in a circular pattern downward.
Upright Heads
Point upward, mounted on top of pipes. Used in warehouses, industrial spaces, and areas with exposed piping.
Sidewall Heads
Mount on walls instead of ceilings. Useful in corridors, small rooms, or where ceiling mounting isn't practical.
Backflow Preventers
Backflow preventers protect your drinking water supply from contamination. They ensure water flows in one direction only—keeping potentially contaminated water from flowing backward into the clean water supply.
Why Backflow Prevention Matters
Fire sprinkler systems are connected to your building's water supply. The water sitting in those pipes can become stagnant and contaminated over time. Without proper backflow prevention, a drop in water pressure could cause that contaminated water to flow backward into the drinking water system—a serious health hazard.
Required by law: Most jurisdictions require annual testing of backflow preventers to ensure they're working properly. Failure to test can result in fines and water service disconnection.
Double Check Valve Assembly (DCVA)
Uses two independent check valves in series. If one fails, the other still provides protection. A reliable, cost-effective option for low-to-moderate hazard situations.
Typical Applications:
- Fire sprinkler systems (non-chemical)
- Irrigation systems
- Commercial HVAC systems
Reduced Pressure Zone (RPZ)
The highest level of backflow protection. Features two check valves plus a relief valve that opens to drain if either check valve fails. Provides maximum protection for high-hazard applications.
Typical Applications:
- Fire systems with chemical additives
- Medical and laboratory facilities
- Industrial processing plants
Pressure Vacuum Breaker (PVB)
Uses an air inlet valve and a check valve. When water pressure drops, the air inlet opens to break the siphon effect, preventing backflow. Must be installed above the highest outlet.
Typical Applications:
- Lawn irrigation systems
- Outdoor hose bibs
- Agricultural applications
Atmospheric Vacuum Breaker (AVB)
The simplest type of backflow preventer. Uses a single check valve and air inlet. Only protects against backsiphonage (not back-pressure). Cannot have any valves downstream.
Typical Applications:
- Simple irrigation setups
- Utility sinks
- Laundry tub faucets
Annual Testing Requirements
Most backflow preventers require annual testing by a certified technician. We're ASSE certified to perform these tests and file the required paperwork with your local water authority.
Inspection Schedule Overview
Different components require testing at different intervals. Here's what you need to know.
| Inspection Type | Frequency |
|---|---|
| Visual inspection of sprinkler heads & piping | Quarterly |
| Alarm device testing | Quarterly |
| Control valve inspection | Quarterly |
| Main drain test | Annually |
| Backflow preventer testing | Annually |
| Fire pump testing | Annually |
| Internal pipe inspection | Every 5 years |
| Sprinkler head replacement (standard response) | 50 years (or per testing) |
We Track It For You
Don't worry about keeping track of all these deadlines. When you work with us, we monitor your inspection schedule and reach out when it's time—so nothing gets missed and you stay compliant.
Have Questions About Your System?
Whether you need an inspection, have questions about your equipment, or just want to understand your system better—we're happy to help.