Fusible Link vs Glass Bulb Sprinklers: Key Differences
When it’s a question of your fire safety, nothing is insignificant. Even the smallest things may play a crucial role when it comes to fire protection. At first sight you might not tell whether you look at fusible link sprinkler heads or glass bulb sprinklers. Though their performance during emergencies differs a lot. Today we are going to break down what sprinkler heads will suit your needs better and how to tell the difference between them.
What is a Fusible Link Sprinkler Head?
Let’s start from the beginning: what is a fusible link sprinkler head? As any other type of fusible sprinkler head, it activates when a temperature in the room reaches a certain level. Inside these heads there are two metal components which are joined by a fusible link. This link is a heat-sensitive alloy and it melts when the surrounding temperature is around 135°F—260°F.
Fusible link fire sprinkler heads are a popular choice among those who need an enhanced protection against vibrations and physical damage. Such systems have a rugged design, so they are widely utilized in industrial and commercial settings.
What is a Glass Bulb Sprinkler Head?
Now we know about fusible link sprinklers, let’s move on to the glass bulb sprinkler. You can call this system a frangible bulb sprinkler head system as well. This type of head has a small sealed glass bulb with a colored liquid which is the main part of this head. The fluid expands because of the heat and that causes the glass to shatter—hence the term frangible—triggering the sprinkler to release water.
The color is a marker for the temperature that needs to be reached for a glass shatter., red for 155°F, orange-175°F, green-200°F, blue—260°F. This colorful design makes a frangible bulb sprinkler head visually appealing, so its easy to integrate into modern interiors. They are less intrusive and can be hidden more effectively behind ceiling tiles or decorative covers.
Response Time: Which One Activates Faster?
When it comes to speed, glass bulb sprinklers generally have a slight edge. The frangible bulb sprinkler head has a faster thermal response because the glass bulb has less thermal mass compared to the solid metal fusible link. This allows it to react more quickly to rising temperatures.
- Fusible link sprinkler heads react a little bit longer to the heat. Although, they withstand more external stress and temperature fluctuations.
- Glass bulb sprinklers or fusible bulbs, on the other hand, activate almost immediately. That’s why they are ideal for fast-spreading fires in confined spaces.
However, the difference in response time may be minimal in practical situations and largely depends on system design and installation.
Pros and Cons of Each Sprinkler Head Type
| Feature | Fusible Link Sprinkler Head | Glass Bulb Sprinkler Head |
| Response Time | Moderate | Faster |
| Durability | Highly durable | Less impact-resistant |
| Aesthetic Design | Industrial | Sleek and discreet |
| Maintenance | Low maintenance | Slightly more fragile |
| Cost | Often more cost-effective | Slightly more expensive |
| Installation Environment | Industrial, warehouses | Offices, hotels, residential |
Fusible Link Sprinkler Pros:
- Great for harsh environments
- Resistant to tampering and physical damage
- Simple, proven design
Fusible Link Sprinkler Cons:
- Not visually appealing
- Slightly slower activation time
Glass Bulb Sprinkler Pros:
- Faster response to heat
- Visually discreet
- Available in multiple temperature ratings
Glass Bulb Sprinkler Cons:
- Can break due to vibrations or impact
- May require careful handling during installation
Best Use Cases for Fusible Link vs Glass Bulb Sprinkler Heads
To make a right choice between fusible link sprinkler and frangible bulb sprinkler, define your needs. Here is our advice on which system you might prefer depending on your business:
Best for Fusible Link Fire Sprinkler Heads:
- Factories and Warehouses. Mechanical equipment makes durability a critical feature of a fusible bulb.
- Commercial Kitchens. There the surrounding temperature is usually higher than in other spaces. Fusible link fire sprinkler heads won’t react at normal cooking heat.
- Data Centers. This system has a very stable design, which reduces false activation.
Best for Frangible Bulb Sprinkler Heads:
- Residential Homes and Apartments. Sleek design fits better with interior décor.
- Retail Spaces and Offices. Offers a balance between performance and aesthetics.
- Hotels and Hospitals. Lower visual impact and quick response times.
At FirePro Tech we are keen to help you choose the best system for your business. Whether you think about a fusible sprinkler head or a glass bulb sprinkler, we are experts in both. We are a trusted fire sprinkler contractor in CA, so we can ensure the system is installed correctly and meets all safety codes. Feel safe and protected with the services we provide by calling us at (818) 860-0166. Check our Facebook and Instagram pages for fire protection content trends.