Problem
Vollers Excavating & Construction was working at an industrial property in New Jersey to verify the location of a leak on a 12-inch steel chilled waterline that was buried 10 feet in the ground. The piping network at the suspected leak location connected to a 90-degree offset straight down, then dropped approximately 20 feet vertically before connecting to another 90-degree offset, allowing the chilled waterline to enter the building’s mechanical room horizontally at a depth of over 30 feet below grade. The excavation cost to construct an engineer-designed safe hole with trench boxes and shoring was more than $100,000. Vollers wanted to verify the leak was on the 20-foot vertical portion of the pipe, justifying replacement at a shallower depth in order to avoid increased excavation costs and more extreme working conditions.
Solution
The company contracted NYLD Infrastructure, a.k.a. New York Leak Detection Inc., to assist in locating the leak. Acoustic listening and leak correlation methods could not be utilized for the process, as the leak was large enough that the pipe could not be fully pressurized. Vollers installed a 2-inch tap on the 12-inch steel waterline for NYLD to use the Investigator from JD7 to do a live insertion for internal condition assessment and leak detection.
Result
The Investigator helped pinpoint the leak nearly 12 feet below the 90-degree elbow on the 20-foot vertical portion of the line. NYLD also determined the internal condition of the pipe was good with no corrosion, pitting or tuberculation, and there was no reason for future concerns.
Technical Data
System:
12” steel chilled waterline
10-30 feet below grade
Customer:
Vollers Excavating & Construction
Location:
New Jersey