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NEWS | Dec. 8, 2020

NNSY Piping Team Stands Ready to Perform with New Freeze Seal Trailers

By Kristi Britt, Public Affairs Specialist

Norfolk Naval Shipyard’s (NNSY) Pipe Shop (Shop 56) was recently outfitted with two new freeze seal trailers – providing the team with the equipment needed to perform their duties for vortex freeze seal repairs.

Freeze seals consist of an intentional mass of ice within a pipe that prevents water movement similar to a shut valve. The entire process is planned, closely observed and the seal itself is capable of holding back pressure from a combination of surface adhesion, and friction with no deformation of the pipe.

NNSY uses several different types of freeze seal techniques – such as freon, liquid nitrogen, liquid carbon dioxide and compressed air that utilize a vortex tube to supply a cooled air stream around the pipe. The vortex tube, also known as the Ranque-Hilsch vortex tube, is a device that separates compressed gases into hot and cold streams – reaching temperatures as hot as 260 degrees Fahrenheit and as low as -58 degrees Fahrenheit. The low temperatures are ideal for freezing pipes to seal them, a method NNSY utilizes not only on the main installation, but across the enterprise.

“Our team here supports our local area including America’s Shipyard and Naval Station Norfolk; however, we also travel to wherever the need is – including Kings Bay, Georgia; Charleston, South Carolina; and Diego Garcia,” said Shop 56 Trade Zone Manager John Wade. “Freeze seal efforts are utilized in a number of availabilities and we’re always ready to travel to meet the needs of the Navy.” 

In 1997, the shipyard purchased used steel shipping containers and outfitted them so that the team could perform vortex freeze seals on the installation, containing compressors, fans, and more to perform the work. These trailers fit the need of the Navy and the workers; however, as they continued to age, it was becoming harder and harder to repair leaks and the flooring. In order to continue to perform vortex freeze seals and to ensure the safety of the personnel working the jobs, NNSY needed a fix.

“Reactor Engineering Division (Code 2310) and Shop 56 came together for a common goal and began designing an all-aluminum 40-foot conex box that could act as the maintenance free enclosure for vortex freeze seals,” said Code 2310.5 Nuclear Engineer Brandon Waltemyer. “These new enclosures would be watertight and outfitted with the equipment needed. The goal for these new conex boxes was to help save the Navy and NNSY funds in maintenance for the trailers while also providing a more habitable space for the workers who would be manning the equipment around the clock. They could also double as a power source for the availabilities should the need arise for it.”

With a plan in place, the team then presented the designs to the Equipment Engineering Branch (Code 981) that acted as liaison for capital equipment between Code 2300 and Naval Facilities (NAVFAC). In support of this endeavor, Naval Sea Systems Command Industrial Operations (NAVSEA 04) agreed to help fund the project so that the project could come to fruition. As of now, two new freeze seal trailers have been fabricated and delivered to NNSY, and two more are on the way to meet the demand.

“Our guys are on the job 24/7 and needed to have the equipment and facilities to get the job done wherever it was needed to be done,” said Wade. “With these new trailers installed, the new equipment is used to get the job done right as safe and quickly as possible. Moreover, insulated walls have been installed to lower the amount of noise inside and a split air conditioning unit to regulate temperatures to keep everything running smoothly. In addition, the trailers are set up to be ready to move whenever we get the call for action. All-in-all, it’s a great asset to our team and to the mission.”

“This team has the coolest jobs in the shipyard in my opinion and I’m excited to see them getting the tools they need to succeed,” said Waltemyer.

Shop 56 Work Leader London Hatten is thrilled to have these new trailers fitted and ready to use. “As a worker, it’s always appreciated when we’re able to get new equipment and facilities to get the job done. A lot of what we do in Shop 56 is hard work, and seeing our shipyard working hard to take care of us means a lot to me.”