Answer :
Final answer:
While the question lacks a specific standard for reference, water distribution systems typically are designed to withstand at least 150 psig at 70ºF, which would be closest to option b) 150 psig at 70ºF, considering general engineering practices.
Explanation:
The question asks about the minimum working pressure required for cold water distribution pipes installed underground, measured in pounds per square inch gauge (psig) at a certain temperature in degrees Fahrenheit (ºF). The available options are a) 100 psig at 60ºF, b) 150 psig at 70ºF, c) 200 psig at 80ºF, and d) 250 psig at 90ºF. Without a specific standard provided in the question, it's challenging to determine the accurate answer as this could vary based on local building codes, material of the pipe, and specific engineering requirements.
However, commonly, water distribution systems are designed to withstand at least 150 psig to accommodate surges and the weight of the soil above for a typical range of ambient temperatures which would cover 70ºF. This is suggestive but not definitive without a pointed reference to a specific standard such as those set by the American Water Works Association (AWWA) or local building codes.
