Water Mist Nozzles

shall be tested for degradation at least annually. Biodiesel fuel might need to be tested for degradation more frequently.

Water Mist Nozzles

Automatic water mist nozzles that have been installed for 10 years (5 for harsh environments) shall be replaced, or representative samples shall be tested.

‍

Why Water Mist Nozzle Compliance Matters

Water mist nozzle performance can change throughout a system’s service life in ways that may not be identified through visual inspection alone. Periodic testing provides objective performance data that can be used to evaluate nozzle conditions and determine whether maintenance or replacement may be necessary.

NFPA 25 requires periodic testing of automatic and open water mist nozzles to evaluate continued performance against established acceptance criteria. Test results can be used to support maintenance decisions and demonstrate compliance with applicable inspection, testing, and maintenance requirements.

Water Mist Nozzle Testing Overview

We test all types of water mist nozzles, including automatic and open nozzles. Water mist nozzle testing is typically performed as part of periodic inspection, testing, and maintenance programs required by NFPA 25. Testing may also be performed when evaluating system conditions, investigating concerns about nozzle performance, or supporting maintenance and replacement decisions.

These services are commonly used by building owners, facility managers, contractors, consultants, insurers, and fire protection professionals responsible for the inspection, maintenance, and long-term performance of water mist fire protection systems.
‍
Key Testing Capabilities Include:

Sensitivity (Automatic Nozzles Only) to evaluate nozzle response characteristics under controlled test conditions and determine whether activation performance meets the applicable acceptance criteria.
Functionality to verify that nozzles fully operate at their minimum operating pressure during testing.
Discharge Coefficient (K-Factor) to evaluate the relationship between flow and pressure and determine whether discharge performance remains within the allowable tolerance of the manufacturer's published K-factor value.
Actionable test reports that provide clear results and recommendations, helping system owners, contractors, and authorities having jurisdiction make informed maintenance and compliance decisions.

If you are interested in the equations and RTI calculations used in the testing process, refer to our Testing Explanation sheets available under Resources.

Free Water Mist Nozzle Sample Kits

Standard Turnaround: 5-business days

Expedited Testing Available: Contact us for pricing.

Quantity Needed

1 Kit = Room for 4 water mist nozzles (minimum of 4 water mist nozzles required by NFPA 25)

2 Kits = Room for up to 8 water mist nozzles

3 Kits = Room for up to 12 water mist nozzles

Applicable Testing

NFPA 25

Kits Include

4 sample tags for labeling
Foam packing material
Sample return form (online available and preferred)
UPS Ground return label (in the contiguous US)

Shipping Information

Ground shipping to you is included, as well as return labels (UPS/USPS) within the contiguous United States (limited free 1-way shipping to Alaska, Hawaii, Puerto Rico, and Canada; inquire for details). Expedited shipping is available at your cost.

How Water Mist Nozzle Testing Reduces Risk and Supports Compliance

Water mist nozzle testing provides objective data on nozzle performance and condition. Automatic nozzles are evaluated for response time, while both automatic and open nozzles are tested for discharge coefficient (K-factor) and functionality. Testing can identify loading, corrosion, paint, missing bulb fluid, or debris that may impair operation.

Results support maintenance, replacement, and compliance decisions by identifying nozzles that do not meet applicable acceptance criteria. In accordance with NFPA 25 (2026 Edition, Sections 12.3.1.5 and 12.3.2.5), if one water mist nozzle within a representative sample fails testing, all nozzles represented by that sample must be replaced.

Periodic testing helps verify system reliability, supports informed maintenance planning, and reinforces confidence that water mist fire protection systems will perform as intended when needed.

Relevant Water Mist Nozzle Standards and Test Methods

NFPA 25 Standard for the Inspection, Testing and Maintenance of Water-Based Fire Protection Systems

2026 Edition Section 12.3.1.1
2026 Edition Section 12.3.2.2 or 12.3.2.3

What types of samples are tested?

Automatic water mist nozzles and open nozzles.

When is Water Mist Nozzle testing typically required?

10 years after installation and every 5 years thereafter. Harsh Environments: Automatic water mist nozzle testing every 5 years, open water mist nozzle testing every year.

How are test results delivered?

Test results are delivered via email within 5 business days or less from the receipt of the sample(s). System tags are mailed via USPS if requested on the sample return form for passing samples.

Who should I contact to get started?

You can contact Dyne Fire Protection Labs to discuss your testing needs.

L'en-tête de l'accordéon apparaîtra ici (utilisez n'importe quelle balise d'en-tête - h1, h2, h3, h4, h5, h6)

Add

remove

Le contenu de l'accordéon apparaîtra ici

It is the responsibility of the property owner or designated representative to ensure the sample information provided is correct and to correct deficiencies or impairments, including identifying and replacing any recalled products. The results relate only to the sample(s) tested using a limited number of laboratory-scale methods and do not guarantee the system will operate properly.

For more information, please review our Legal Notice page. 

Why NFPA Global Solutions Water Mist Nozzle Testing

Dyne Fire Protection Labs, an NFPA Global Solutions company, is a full-service NFPA 25 testing laboratory that combines fire protection industry expertise with specialized water mist nozzle testing services. Our approach focuses on delivering objective laboratory data that helps organizations evaluate nozzle performance, support maintenance planning, and make informed decisions related to system reliability and compliance activities.

With more than 25 years of testing experience, we understand the unique challenges associated with maintaining water mist fire protection systems. Our testing services are designed to help organizations assess nozzle conditions, document results, and maintain confidence in the performance and readiness of their fire protection systems.

Testing Advantages:

Test reports in 5-business days or less (with rush 24-hour turn-around available)
Free Water Mist Nozzle sample kits
Free shipping within the contiguous United States (limited free 1-way shipping to Alaska, Hawaii, Puerto Rico, and Canada, inquire for details)
Comprehensive reports and system tags
Online access to results and return forms
Immediate communication with our quality technicians and customer service staff

Additional Resources

arrow_outward

Water Mist Nozzle Testing

arrow_outward

Sample of a Completed Water Mist Nozzle Form

arrow_outward

Water Mist Nozzle Sample Return Form

arrow_outward

Water Mist Nozzle Testing Explanation

Order Your Water Mist Nozzles Kit

Request your free Water Mist Nozzle sample kit and connect with our team to discuss your testing needs. We can help determine sample requirements, answer questions about the testing process, and provide guidance on submitting samples for evaluation. If you have questions, contact us at (800) 632-2304 or dyne.lab@nfpaglobal.com.

Order Today

arrow_right_alt