Ultrasonic Liquid Level measuring for firefighting cylinder
utilizing FK-5-1-12 or HFC-227ea
Accurate cylinder monitoring is relied upon to keep firefighting systems compliant, serviceable, and ready to perform. Liquid level measurement plays a direct role in system integrity, inspection confidence, and regulatory approval.
This article explains how non-invasive ultrasonic liquid level measurement now meets the strict requirements applied to firefighting cylinders using FK-5-1-12 and HFC-227ea. You will see how collaboration between Coltraco Ultrasonics and Viking EMEA led to FM approval, why system-specific approval matters, and what this change means for system owners, service providers, and inspectors working under NFPA 2001 requirements.
Measuring the liquid level, using ultrasound, inside a cylinder with liquefied gas is standard in the fire industry since many decades. So far, only invasive methods utilizing a mechanical liquid level indicator where available have been approved for firefighting systems.
In 2023, Coltraco Ultrasonics and Viking EMEA joined forces to develop a non-invasive liquid level indicator utilizing ultrasound. It was essential for Viking EMEA that the finished unit would comply with regulations, such as NFPA 2001 clause 5.1.4.5: Where a liquid-level indicator (LLI) is provided as a component of the container assembly, the LLI and method of measuring the agent quantity shall be listed.
To ensure that Viking EMEA can offer their customers an ultrasonic liquid level indicator that meets the accuracy requirements of the notified bodies, across the system temperature range, Coltraco and Viking EMEA conducted a test and development series. This test series led to a software customized version of one of Coltraco’s ultrasonic liquid level indicators, bringing the Portatank® Viking EMEA.
This unit was successfully witness tested and approved by FM (Factory Mutual) in December 2024 and listed with the VSN 1230 system (FM23FPUS0045) and the VSN 200 system (FM23FPUS0058). This approval also includes a marking done by factory or authorized first fill companies offering VSN 1230 and VSN 200 systems. Copies of the certificates are available from Viking EMEA.
Coltraco and Viking EMEA are delighted to provide the firefighting market with the first FM approved Non invasive Ultrasonic Liquid Level Indicator and want to emphasize that only ultrasonic units approved with the firefighting system are eligible substitutes for Mechanical Liquid Level Indicators.
Coltraco Ultrasonics are global leaders since more than 35 years in the monitoring of liquefied extinguishing systems that protect high-asset value assets.
Viking EMEA Since its founding in 1989, Viking EMEA has been a key player in fire protection across Europe, the Middle East, and North Africa. With a diverse team of over 200 professionals representing more than 25 nationalities, Viking EMEA serves 2,100 clients across 74 countries. The company offers a comprehensive range of fire protection systems, including water and deluge systems, water mist, foam, gas, and detection & control technologies for commercial, residential and industrial applications.
What This Means for Your Fire Suppression Systems
You now have access to an FM approved, non-invasive ultrasonic liquid level indicator listed with specific firefighting systems. This removes the need to rely only on mechanical indicators while keeping full compliance with NFPA 2001 and notified body accuracy requirements.
System approval matters. Ultrasonic units approved with the firefighting system remain the only acceptable replacements for mechanical liquid level indicators. Using unlisted equipment places compliance, certification, and system performance at risk.
