73. When may one bathtub and one laundry sink be installed on a 1 1/2-inch horizontal waste branch without re-venting
Answer: A
One bathtub and one laundry sink may be installed on a 1 1/2-inch horizontal waste branch when the most remote fixture is within a developed length of 3 feet 6 inches from a main vented line.
Installing a bathtub and a laundry sink on a 1 1/2-inch horizontal waste branch is permissible if the most remote fixture is within a developed length of 3 feet 6 inches from a properly vented main line, ensuring adequate drainage and venting.
A) When the most remote fixture is within a developed length of 3 feet 6 inches from a main vented line
This option is correct as it adheres to plumbing codes that allow for the installation of these fixtures without requiring additional venting when they are within this specified distance from a vented main line. This distance helps in maintaining proper drainage and preventing siphoning of the traps.
B) When the most remote fixture is within a developed length of 5 feet from a main vented line
This option is incorrect because the specified distance exceeds the allowable limit for installation without re-venting. At 5 feet, the risk of inadequate drainage and venting increases, which could lead to plumbing issues.
C) When the most remote fixture is within a developed length of 6 feet from a main vented line
This option is also incorrect as it goes beyond the established limit for installation without requiring re-venting. A distance of 6 feet may lead to insufficient venting, which could negatively impact the performance of the fixtures.
D) They cannot be installed there. The horizontal branch is too small
This option is incorrect because it misinterprets the capacity of a 1 1/2-inch horizontal waste branch. The installation is viable within the specified limits regardless of the branch size, provided that the distance to the vented line is adhered to.
Conclusion
Option A is definitively the correct answer as it correctly aligns with plumbing code requirements for fixture installation without re-venting. Options B and C exceed the permissible distance, while option D incorrectly assumes a limitation based solely on branch size, ignoring the critical distance factor. Understanding these specifications is essential for ensuring proper plumbing functionality.