The best approach to leak locating in a cable pressurization system is to use a logical and organized step-by-step procedure. When a defined leak locating strategy is applied, the most damaging leaks in the system are identified first. These are the ones that generally bring down route delivery pressures and reduce cable protection throughout the system. Only after these major leaks have been located should the emphasis shift to the smaller leaks.

To provide a structure for the leak locating process, System Studies has developed seven leak locating worksheets, each of which addresses a specific leak locating challenge. The information below briefly describes each worksheet and provides links to PDF versions. These can be printed out and used in the field to help you zero in on the leaks.

NOTE: If you don't have AdobeAcrobat®Reader™ installed on your system, you can download it for FREE here.

Worksheet A—Reading Air Flow at Manifolds and Meter Panels.
This worksheet is used to record pressure and flow readings at air pipe manifolds and meter panels. It will identify problems in the air pipe and indicate the hightst flowing cables on each air pipe run—the ones to work on first. Worksheet A is used on air pipe runs where the end point delivery pressure has dropped below 7 Pounds per Square Inch (PSI) as a result of high air consumption.

Worksheet B—Chasing Air Flow at a Manifold.
When high air usage is measured at a particular manifold location, Worksheet B is used to provide direction for chasing the air flow. The worksheet includes a step-by-step procedure that will reduce the area of search and lead you to the leak.

Worksheet C—Leak Locating in Cables Leaving the Central Office.
Cables leaving the central office can be systematically checked for leaks by following the procedures on Worksheet C. This worksheet is designed to help you chase leaks that are identified as high flows at the meter (or distribution) panel.

Worksheet D—Leak Locating in Dual Feed Cables.
Worksheet D is used when air pipe pressure at an end point pressure transducer is above the minimum delivery pressure of 7 to 7.50 PSI (the actual requirement depends on local pressurization standards), and a midpoint pressure transducer associated with the air pipe indicates that cable pressures are below standard (5 to 6 PSI for underground cables).

Worksheet E—Leak Locating in Single Feed Cable.
Worksheet E is used for leak locating on single feed underground, aerial and buried lateral cables. It is used for demand leak locating (in response to a low pressure transducer reading at a cable end point) and for routine cable maintenance.

Worksheet F—Leak Locating on Trunk and Toll Cables.
This worksheet is used on trunk and toll cables to calculate pressure drop per foot and quickly identify the section of the cable with the leak. When used properly, it will enable you to eliminate large sections of cable and concentrate on a specific portion of the cable.

Worksheet G—Reading Flows at the Flow Bank.
This worksheet is used exclusively in the Flow Bank System for leak locating. When used to list pressure and flow readings, Worksheet G provides an ongoing record of the system's status. The worksheet is used to record flow readings for each cable at all Flow Bank locations.