Identify all valves, fittings, and appurtenances. If you are crossing other utilities or drainage take those GPS shots too because they act as a witness to future excavations. Additional items you may include in Waterline As-Built’s are easements, property lines, service saddles, identify abandoned pipe sections that have been removed or grouted with a mason plug. If we follow the As-Built Checklist guidelines, these points can easily be found, and you can precisely excavate and not blindly dig. The leak will always be found at a bell, valve, or at any mechanical fitting such as a 11 ¼”, 22 ½”, 45, 90, a saddle, or a tee. Eventually, we found it, but the amount of time spent finding the leaks would have been substantially shortened if we knew where the bells and mechanicals were located in the ground. We didn’t know where any of it was so we ended up digging the whole 500’ line - we mean the entire run stopping at every bell and mechanical fitting digging from within a foot of the line and all around the bell or fitting to check for small signs of leaks and we found none. As mentioned before, a previous foreman set the line without taking As-Built shots on the bells or the mechanicals. Oh boy, the worst kind of failure and now we had to find it. Then we started losing pressure at about 1 psi every 2-5 minutes. Everything held, and we shut down the hydrant and blow off valve. We turned on the valve slowly and forced the air out of the line. At first, it appeared that everything was done right with a fire hydrant midline and blow-off valve at the capped end to allow us to blow off air in the line. It was time for the hold test, which turned out to be a 2-hour hold at 150 psi. We performed an air-test, and everything passed. We were tasked with pressure testing the installed 18” Water Main.
#What does as built drawing mean install
Our crew was brought in the following season to install curb and grade a parking lot and establish grade for the sidewalks. It was connected to the existing with a valve and capped at the other end with a blow-off valve to allow pressure testing. While working on a job recently, we noticed an 18” ductile water main was put in the previous season by a different crew. The GPS cannot help you pinpoint the leak, but it can help you locate the areas where the leak is bound to be found. We want to share with you how the topo shots from an As-Built drawing can help you find the subtle failure. However, we are not here to discuss the obvious failures. Of course, the ideal situation is a total failure because the problem becomes evident – the bubbling dirt gives it away. Once the plan is established, then the fun begins – the tedious task of trying to find the leak somewhere in the backfilled line. Now what? We can guarantee that the next morning there will be a slew of white hats huddled in a circle coming up with a game plan.
Ok, perhaps not the part about the stars lining up. It happens, not every time, but it happens. Other possible failure scenarios are a folded over rubber gasket, an under-torqued mechanical fitting, an over-deflected pipe, a defective valve, and maybe even the stars lined up in a certain way. It sounds straight forward in theory, but a grain of sand on the rubber gasket is enough to make one of these tests fail. The frustration begins when the line must pass an air test, a pressure test, and a two-hour pressure hold test at 1.5x the typical mainline pressure. What would you say are the most troublesome proposed utilities on a job site? In our experience, we would easily say waterlines! Requirements, such as keeping it under the frost line and passing a bacteria test, are straight-forward. Let’s take a real-world example of As-Built drawing points and how they relate to waterlines. The primary function of an As-Built drawing is to record any changes made during the building process that deviates from the original plan The points taken from an As-Built drawing can be useful in other ways. They reflect all of the changes made during the construction process. As-Built drawings are modified sets of drawings submitted by a contractor upon the completion of a job.