Encapsulation Method Keeps Valve Functioning, Seals Leaks

By Jeff Griffin, Senior Editor | July 2009 Vol. 64 No. 7
The leaking flange valve has to be blasted clean before the mold could be installed.

"Creation of the mold to the project's specifications is the most critical step in the process because there is little margin for error," said Kasmin. "For a proper seal, the form for the mold had to be constructed to exact measurements specified in the design."

The mold was constructed in four pieces and when assembled measured 4½ feet wide by 10-feet high. Produced entirely in house, Miller’s design, fabrication, paint and shipping departments devoted 200 hours to the project.

From the time the valve was exposed and measurements taken to its installation took about two months, said Guariglia. While the mold was being fabricated, permitting, out sourcing and other preparations were completed.

Prep

To prepare for installation of the mold, Miller crew members spent a day cleaning the valve. The mold was assembled, and nine crewmen mixed and poured the polyurethane sealant into the mold through four pressure pots. Work started early in the morning and was completed about midnight, using 314 gallons of sealant to fill the mold.

"Because Safe-T-Seal begins to gel in 15 minutes after mixing, coordination of the mixing and pouring process is critical," said Kasmin.

The mold was disassembled and removed two days later, and tests confirmed there were no leaks.

Guariglia said the valve repair was successful.

"The leaks were stopped, the valve continued to function throughout the procedure, and there was little disturbance to the neighborhood," he reported. "The town commended us for a job well done. Miller Pipeline has served us well on other projects and is familiar with PSE&G procedures. Miller personnel have the experience and ability to do the job right the first time, and came through with an effective solution for us."

PSE&G is part of the Public Service Enterprise Group. It is one of the largest combined electric and gas companies in the United States and is also New Jersey's oldest and largest publicly owned utility. Its service area comprises nearly 75 percent of New Jersey's population across a 2,600 square mile service area that includes 2.1 million electric customers and 1.7 million gas customers in more than 300 urban, suburban, and rural communities, including the state's six largest cities.