Insurance adjusters are often faced with a large loss caused bywater leakage from plumbing systems. Investigating the cause is anintegral part of the claims adjustment process since it bears oninsurance coverage as well as potential subrogation. The first stepis finding the source and determining the nature of the leak. Wasthis a result of some manipulation of valves, either intentional orunintentional, or perhaps a failure of the pipe system?

Photographing the leakage source and documenting thecircumstances of the leakage is helpful for those performing a moredetailed analysis of the problem. The following case study servesto illustrate a water leakage loss as a result of a failedpipe.

Figure 1 shows a water valve that became detached from a 2.5inch pipe, causing flooding of lower floors of a high-rise buildingand a multi-million dollar loss. The pipe failed in the threadedsection as shown in Figure 2 (arrow).

Since there is potential subrogation against the plumbingcontractor, they should be placed on notice in order to have achance to inspect the scene prior to repair. After the inspectionby the plumbing contractor and other potential litigants, theevidence should be removed for future detailed examination of thecomponents.

Examination of the threaded section of the failed pipe resultedin the photo of Figure 3 (left pipe section). The threads on thefailed pipe appear very deep, almost penetrating the pipe crosssection. The lines as indicated by the thread root penetration aredeformations of the pipe by the thread die forming the root of thethread.

Measurements of this pipe showed it to be American NationalStandard Institute (ANSI) Schedule 10 pipe. The pipe thread usedwas an American National Standard pipe thread. The pipe at theright in Figure 3 is Schedule 40 pipe with the appropriate standardtapered pipe thread. It is known in the plumbing industry thatSchedule 10 pipe cannot be threaded because the pipe wall thicknessis too thin. Typically, a rolled groove coupling system is onemethod of joining Schedule 10 pipe with other components.

In this particular case, the pipe wall thickness was reducedsignificantly by the improper threading, resulting in pipe failureand the water loss. Over time, water pressure variations causedfailure of the pipe due to the thin and weakened wall crosssection. The root cause of the loss is improper plumbingconstruction and installation. Retention of evidence (valve, failedpipe section), taking statements of building personnel anddocumenting the circumstances will aid in a successful recovery forthe insurance adjuster's client.