What should the invert elevation of a 36" diameter outlet pipe be if the rim elevation of the catch basin is 68.75?

What should the invert elevation of a 36" diameter outlet pipe be if the rim elevation of the catch basin is 68.75?

• A. 62.25
• B. 63.25
• C. 63.75
• D. 64.00

Answer: (B)

To determine the proper invert elevation for a 36-inch diameter outlet pipe connected to a catch basin with a rim elevation of 68.75, it is essential to account for standard installation practices regarding the placement of pipes. The invert elevation is the lowest internal point of the pipe, which is critical for ensuring proper drainage and preventing potential water pooling within the catch basin. Typically, the centerline of a pipe is set at half its diameter above the invert elevation. For a pipe with a 36-inch diameter, the radius is 18 inches. Thus, to calculate the invert elevation, one can subtract the radius from the rim elevation of the catch basin. Performing the calculation: 1. The rim elevation is 68.75. 2. The radius from the centerline to the invert is 18 inches. If we subtract 18 inches from the rim elevation: 68.75 - 18 = 50.75. However, we should recognize that to identify the invert elevation at the bottom of the pipe correctly, the appropriate approach would typically take into consideration the pipe's slope and ensure the water is directed away efficiently. The common practice is to determine the invert elevation based on slope requirements or hydraulic flow considerations. With the provided choice of

To determine the proper invert elevation for a 36-inch diameter outlet pipe connected to a catch basin with a rim elevation of 68.75, it is essential to account for standard installation practices regarding the placement of pipes. The invert elevation is the lowest internal point of the pipe, which is critical for ensuring proper drainage and preventing potential water pooling within the catch basin.

Typically, the centerline of a pipe is set at half its diameter above the invert elevation. For a pipe with a 36-inch diameter, the radius is 18 inches. Thus, to calculate the invert elevation, one can subtract the radius from the rim elevation of the catch basin.

Performing the calculation:

1. The rim elevation is 68.75.

2. The radius from the centerline to the invert is 18 inches.

If we subtract 18 inches from the rim elevation:

68.75 - 18 = 50.75.

However, we should recognize that to identify the invert elevation at the bottom of the pipe correctly, the appropriate approach would typically take into consideration the pipe's slope and ensure the water is directed away efficiently. The common practice is to determine the invert elevation based on slope requirements or hydraulic flow considerations.

With the provided choice of