
By: Forest Hampton on December 19th, 2024
freezemaster™ Antifreeze: STILL the Only Product UL-Listed for Galvanized Piping
FAQs | Corrosion | Codes | Standards & Approvals
Piping materials for fire sprinkler systems vary based on budget, location, when the system was designed, contractor preference and more. Although more common in dry pipe fire sprinkler systems, there are many existing and new wet systems made with galvanized pipe. For these, there is only one UL-listed antifreeze approved for use with galvanized piping: freezemaster™ antifreeze.
What Makes Galvanized Piping Different
Unlike traditional metals that form a reddish rust (iron oxide) when corroding, galvanized piping corrodes to white. The sacrificial layer of zinc on the pipe forms zinc oxide when exposed to moisture and oxygen, forming a protective layer over the underlying metal.
Listed antifreeze contains, in part, some of the same things present in unlisted fluids that can corrode galvanized piping—water and oxygen. But unlike unlisted fluids, UL-listed antifreeze products must meet UL 2901 standards for corrosion resistance. This standard, established in December 2013, requires premixed antifreeze solutions must not cause the corrosion to exceed 1.0 mils per year (0.025 mm/year) for:
- ASTM A108, Grade 1010 steel
- ASTM B16, H02 (Half Hard) brass
- Type 304 stainless steel
- Additional representative metallic materials other than these or any metallic plating referenced in the manufacturer’s instructions as being compatible with the antifreeze solution.
Not specified in UL 2901? Galvanized piping. Knowing that many existing systems are made with this material, Lubrizol worked with Underwriter’s Laboratories (UL) to undergo additional testing to confirm that freezemaster™ antifreeze is compatible with galvanized piping.
freezemaster™ Antifreeze Went Above and Beyond to Earn Its Galvanized Pipe UL Listing
Some other listed antifreeze products claim they are rated for use with “all” materials, but this is technically incorrect. Only freezemaster™ antifreeze has earned this UL listing, due to its additional testing and superior corrosion inhibition package.
freezemaster™ antifreeze exceeds UL requirements, effectively reducing pipe corrosion by up to 65%. Lubrizol scientists put freezemaster™ antifreeze through many additional corrosion tests to produce the highest-quality listed antifreeze product. These tests included in-house galvanic safeguard testing per ASTM G71 “Standard Guide for Conducting and Evaluating Galvanic Corrosion Tests in Electrolytes.”
freezemaster™ antifreeze also underwent 336 hours of testing for microbiologically influenced corrosion (MIC) along with a competing listed antifreeze. Although neither solution showed signs of corrosion, DNA testing determined that only freezemaster™ antifreeze lacked any sign of continued biofouling from bacterial growth conducive to the formation of MIC.
Another quality that makes freezemaster™ antifreeze suitable for use with galvanized piping is its very low conductivity: freezemaster™ antifreeze meets UL 2901 requirements for a conductivity rate under 7000 microsiemens (µS).
Additional Benefits
Factory-premixed freezemaster™ antifreeze also protects fire sprinkler systems from freezing in temperatures as low as -12°F (-24°C). It can be installed and serviced in all new and existing fire sprinkler systems for Residential, Light Hazard, Ordinary Hazard and Storage applications to help meet requirements for NFPA 13/R/D and 25. It is also tinted blue to easily identify a fully flushed and filled system compared to a clear or rust-colored fluid.
Don’t Settle for Less than the Best Listed Antifreeze
Always consult a listed antifreeze product’s technical data sheet. If the compatibility section does not specifically list galvanized steel, the antifreeze either did not complete the additional required testing for galvanized pipe or failed this test.
Earning a UL listing for use with galvanized piping doesn’t just prove that freezemaster™ antifreeze will work with your galvanized system. It also demonstrates that, in choosing freezemaster™ antifreeze, you get Lubrizol’s extensive expertise in material compatibility and focus on science, service and safety.