Mueller Streamline, a subsidiary of Mueller Industries, has released double-sealed ACR copper flameless press fittings that are “the first in the world that [contain] a primary and secondary seal,” with a focus on HVAC applications, said Chris Mueller, Vice President of Mueller Streamline.
Mueller shared this news at the 2023 AHR Expo held in Atlanta, Georgia, February 6–8.
“There are other press-type fittings that are mechanically crimped that have an O ring in them,” said Mueller. “The difference is we [put] primary and secondary rings on every fitting.” Double-sealed designs exist for other products like ball valve stems, but “it’s never been done before for a press fitting,” he added.
The market for this product is a wide range of field-installed HVAC equipment, including commercial systems with variable refrigerant flow (VRF), industrial and residential split systems, he said.
The press fittings avoid the need for brazing, which includes “a torch, flowing nitrogen, and fire risk,” said Mueller. Thus the flameless press fittings are particularly suitable for propane (R290) and other flammable refrigerants, he added.
In the U.S., the company is preparing for wider use of R290 in HVAC and in the meantime gearing the product to A2L applications, with plans to market the fittings later this year in Europe, where R290 is already used in HVAC.
For the piping connection, the jaws of an electro-hydraulic tool ‒ a full-sized press tool available on the market ‒ squeeze the press fitting, locking it onto the piping with a double seal.
Mueller Streamline offers press fittings for HVAC&R applications with similar lay lengths and patterns as traditional brazed copper fittings, including couplings, elbows, tees and more. The outside diameters of the fittings range from ¼ to 1-⅜in (0.64 to 3.49cm).
Founded in 1930, Mueller Streamline (headquartered in Collierville, Tennessee) is an integrated manufacturer and distributor of piping system solutions that has manufacturing and distribution centers located across the U.S. Along with copper press fittings, the company manufactures copper tubing, line sets, valves and other items for HVAC&R applications, refrigeration, plumbing, medical gas and other systems.
Mueller Streamline’s offerings also include XHP copper tubing, fittings and other ancillary products for the operating pressures and temperatures of CO2 (R744) systems.
“We [put] primary and secondary rings on every fitting.”Chris Mueller, Vice President of Mueller Streamline