What is the required pipe size for section E?

What is the required pipe size for section E?

• A. 1 1/2 inch
• B. 1 1/4 inch
• C. 2 inch
• D. 3/4 inch

Answer: (A)

Gas piping size is determined by the amount of gas you need to move (the total BTU per hour downstream) and the allowable pressure drop along the run. You look at the section’s length and the combined demand from all appliances served, then use a piping sizing chart or the calculation to find the diameter that keeps the pressure drop within the safe limit for the system. In this case, the section E run has enough length and total demand that only a one-and-a-half inch pipe will keep the pressure drop within the acceptable range. A smaller diameter would cause too much pressure loss, starving the appliances at the far end, while a larger diameter isn’t necessary for this load and would add unnecessary cost. So one-and-a-half inches is the appropriate size for that section.

Gas piping size is determined by the amount of gas you need to move (the total BTU per hour downstream) and the allowable pressure drop along the run. You look at the section’s length and the combined demand from all appliances served, then use a piping sizing chart or the calculation to find the diameter that keeps the pressure drop within the safe limit for the system.

In this case, the section E run has enough length and total demand that only a one-and-a-half inch pipe will keep the pressure drop within the acceptable range. A smaller diameter would cause too much pressure loss, starving the appliances at the far end, while a larger diameter isn’t necessary for this load and would add unnecessary cost. So one-and-a-half inches is the appropriate size for that section.