Final answer:
The maximum allowed propane supply pressure for a single-family dwelling is around 14 inches water column (inWC), influenced by factors such as temperature variations and hydrostatic pressure.
Step-by-step explanation:
The maximum propane supply pressure allowed in a single-family dwelling is approximately 14 inches water column (inWC). This level of pressure ensures the safe operation of appliances and equipment that utilize propane. Understanding the pressure levels is critical, especially when considering the variations that temperatures may bring due to Gay-Lussac's Law, which states that the pressure of a given mass of gas varies directly with the absolute temperature when the volume remains constant. In addition, it's worth noting that if we create a perfect vacuum, the atmospheric pressure at sea level is enough to support a column of water roughly 10.3 meters high due to hydrostatic pressure.