Final answer:
To determine the minimum size Type L copper tubing that may be used, we can use the formula: Tubing size = (Propane load x Distance) / Pressure drop. Assuming a pressure drop of 0.5 in w.c., the minimum size Type L copper tubing is 62,400,000 btu ft.
Step-by-step explanation:
To determine the minimum size Type L copper tubing that may be used to connect the first stage regulator and the second stage regulator, we need to consider the propane load on the house and the distance between the regulators.
We can use the formula:
Tubing size = (Propane load x Distance) / Pressure drop
The pressure drop can vary depending on the specific installation, but a common value is 0.5 inches of water column (in w.c.).
Let's assume a pressure drop of 0.5 in w.c. and substitute the values:
Tubing size = (520,000 btu/hr x 60 ft) / 0.5 in w.c.
Simplifying the equation:
Tubing size = 520,000 btu/hr x 60 ft x 2
Tubing size = 62,400,000 btu ft
Therefore, the minimum size Type L copper tubing that may be used is 62,400,000 btu ft.