Mix Fusible Links with Glass Bulbs in Same Area?

7/17/2025

Is there anything in NFPA 13 that states you cannot mix fusible link and glass bulb heads within the same area as long as both sprinklers are standard response?

Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

6 Comments

Peter Howard

7/17/2025 06:18:26 am

There's no reason I can think of you can't as long as both sprinklers are the same response type.

You may run into an issue if the temperature classifications are different (like if all the fusible links are high-temp and all the bulbs are standard)

Anthony

7/17/2025 08:13:57 am

Its perfectly legal, happens a lot with replacement heads.

Dan Wilder

7/17/2025 08:23:20 am

Matching response type (quick or standard) is the only requirement, see 13-19' 9.4.3.1 with the exceptions of Residential/QR sprinklers see 13-19 12.1.4 and use of sprinklers listed as SR but contain a QR operating element (9.4.3.5). The 22 edition has a new chart in 7.2.4.1 for Temp Ratings and Classifications that separate Glass Bulb and Link to assist in matching classifications between the two.

The operating element material used is not a factor for installation adjacent (unless you're in an area that requires one over the other like a food processing facility that is not super happy with any possible glass intrusions).

Glenn Berger

7/17/2025 08:55:59 am

As others have mentioned, as long as the characteristics are the same it is technically permissible. Possibly need to update the spare sprinklers that should be kept in the sprinkler cabinet and update some documentation.

Franck

7/17/2025 09:57:45 am

I confirm all of the above.

As long as type (standard spray), temperature, K-factor and response time are similar, no issue.

Chris Nelson

7/18/2025 06:36:23 am

Only thing is how big is the space? Warehouse size room, sure mix'em, as people said as long as temp and response type are the same.

Small room? Just replace them all in my mind. The system will already be down. Avoid confusion for the next guy (or girl).

Leave a Reply.

Home
Our Cause

The Blog
The Forum

PE Exam Prep
The Toolkit
MeyerFire University

Pricing
Login
Support
Contact Us

MeyerFire.com is a startup community built to help fire protection professionals shine.
Our goal is to improve fire protection practices worldwide. We promote the industry by creating helpful tools and resources, and by bringing together industry professionals to share their expertise.

MeyerFire, LLC is a NICET Recognized Training Provider and International Code Council Preferred Education Provider.
All text, images, and media Copyright © 2016-2025 MeyerFire, LLC

We respect your privacy and personal data. See our Privacy Policy and Terms of Service. The views, opinions, and information found on this site represent solely the author and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence.

Discussions are solely for the purpose of peer review and the exchange of ideas. All comments are reviewed. Comments which do not contribute, are not relevant, are spam, or are disrespectful in nature may be removed. Information presented and opinions expressed should not be relied upon as a replacement for consulting services. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a small commission for orders placed elsewhere.

Mix Fusible Links with Glass Bulbs in Same Area?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES