What is the smallest size of iron pipe required for a system with 165 cubic feet/hr of gas at 1 psi?

To determine the smallest size of iron pipe required for a system delivering 165 cubic feet per hour of gas at a pressure of 1 psi, one must consider several factors, including the flow rate of the gas, the type of gas being used, the pressure drop in the system, and the physical properties of pipe materials.

The provided flow rate of 165 cubic feet per hour is a crucial data point for calculating the required pipe size. In gas distribution systems, pipe sizing is often determined using established flow tables that take into account the gas type, pressure, and flow rate. Based on typical gas flow calculations, a 2-1/2 inch pipe diameter is commonly recognized as suitable for accommodating the flow without significant pressure loss at the specified conditions.

The choice of 2 inches would likely lead to a higher pressure drop, potentially resulting in insufficient gas delivery performance at 1 psi. Meanwhile, the options of 3 inches and 3-1/2 inches would provide excess capacity, which might not be necessary for a flow rate of 165 cubic feet per hour under 1 psi pressure, making them larger than required for this application.

Therefore, sizing the pipe to 2-1/2 inches allows for adequate flow capacity while balancing