Moving to Flourine-Free Foam

Lehigh Valley International Airport (ABE) started serving residents of Eastern Pennsylvania in 1929. As airline travel continued to increase in popularity, the airport expanded. It became a hub for vacationers and leisure travel and served the growing number of business travelers in the region.

This included Bethlehem Steel, which managed a stable of jets out of Hangar 7 at ABE. The approximately 27,000 square foot hangar was built for their sole use in 1958, when Bethlehem Steel was the second largest steel manufacturer in the United States. Time passed, the global economy changed and by 1985, Bethlehem Steel divested their interest in Hangar 7, which is now operated by the Lehigh-Northampton Airport Authority (LNAA).

The Airport Authority has operated Hangar 7 since 2004, and by 2018, the LNAA decided to upgrade building systems in Hangar 7, including its Aqueous Film Forming Foam (AFFF) system. Around the world, more stringent regulations on the use of AFFF are being introduced to limit the use of per- and polyfluoroalkyl substances (PFAS), but at the time that was not the case in the state of Pennsylvania. The LNAA, with support from Aircraft Rescue & Firefighting Department (ARFF) Chief John Demyan at ABE, decided to transition prior to any mandate to a more sustainable long-term solution and go fluorine free. 

The existing foam system was installed more than 60 years ago, and to retrofit a current generation foam system in the space presented significant design challenges.  It would ultimately require a team effort to overcome the obstacles of delivering the latest-generation foam system inside the 1958 hangar. 

Old Building, New Obstacles

To retrofit and install an upgraded foam system at a facility not designed to the latest requirements and standards, dictated that a series of questions should be answered long before construction would begin:

• How was the system originally designed in 1958 and intended to function?
•  Will a redesign of the hydraulic system be required?
• Can the existing piping be reused?
• Will changes to sprinkler head type and quantity be necessary?

Addressing and understanding these unknowns can help determine the length of the installation process, while also ensuring operational success. 

First, ARORA Engineers, Inc. was selected by the Airport Authority to conduct an evaluation to determine if the existing water supply contained enough pressure and capacity to support a new firefighting foam system without the need for major changes.  The simple answer was, yes!

Guy M. Cooper, Inc. a licensed sprinkler contractor, and Perimeter Solutions teamed up on a previous design to convert another hangar at the Airport to a National Fire Protection Association (NFPA) 409 (Standard on Aircraft Hangars) compliant fluorine-free foam system.  Cooper had previously helped the Airport transition its 54,000 square-foot Hangar 11 to an FFF system.  Hangar 11’s new foam system was designed with SOLBERG RE-HEALING RF3 3% Foam and SOLBERG-approved hardware. SOLBERG RF3 foam systems were first introduced in the market in 2010 and remain today as the only fluorine-free foam system that is Underwriters Laboratory (UL) certified and Factory Mutual (FM) approved with a full complement of hardware including foam water sprinklers.  SOLBERG® RE-HEALING RF3 3% Class B Foam Concentrate are fluorosurfactant, fluoropolymer-free products (no intentionally added PFAS) for use on Class B hydrocarbon fuel fires. 

The next step in establishing the fire protection needs for Hangar 7 was to determine the Aircraft Hangar Classification.  Although the square footage of the hangar was under 40,000 square feet, the door height was over 28’, which led the design team to follow guidelines of NFPA 409 and a Group 1 hangar classification.  

The NFPA 409 design scheme chosen for Hangar 7 was a low expansion foam water deluge system, 0.16 sprinkler density at the ceiling with 10-minute foam supply along with a supplemental hose reel station system having a 20-minute foam supply.  Total system demand required 3,200 gallons of foam concentrate supplied by two 1,600-gallon horizontal bladder tanks. An existing storage and break room within the shop space of the Hangar was renovated to accommodate the new tanks. 

After comprehensive review of system options in Hangar 7, it was clear that SOLBERG RE-HEALING RF-3 would once again be the right FFF solution for ABE, offering UL listed components and system application rates that met the requirements of NFPA 409.  

The Installation

The existing fire protection system for Hangar 7 had been modified over the years, with an overhead wet deluge sprinkler system along with a decommissioned AFFF system that supplied foam to hose reels located throughout the hangar floor.  The LNAA worked with ARORA Engineers and Guy M. Cooper, Inc. (Mechanical and Plumbing Contractor) to design, retrofit, and install an entirely new overhead foam-water deluge system and a new foam-water hose station system.  Hydraulic calculations led to the design of a new 3 zone overhead foam water sprinkler system utilizing Reliable® Automatic Sprinkler DDX deluge valves, Reliable® sprinkler heads along with SOLBERG bladder tanks, proportioners and an RF3 fluorine-free foam concentrate. The ARORA team created the original design scope, in which Guy M. Cooper, Inc. used to produce and calculate the final design drawings and submittal package for LNAA’s approval.

The installation was completed 2 months ahead of schedule due to efficiencies of combining phases of the project previously identified, along with being on budget using SOLBERG RE-HEALING RF3 as the FFF solution, meeting all NFPA 409 requirements. 

The project at ABE was completed in February 2021. After a four-year journey with the Airport, Hangars 7 and 11 have been completed and Perimeter Solutions continues to support the Airport’s fire protection needs. As PFAS-containing foams becomes more regulated, more airports will be making the transition to fluorine-free foam systems. Fluorine-free foam concentrates, like SOLBERG RE-HEALING RF3, have demonstrated that the industry has an effective solution that offers a proven alternative to legacy AFFF.  

Todd Wayshville is the sales director for Americas at Perimeter Solutions.