Plumbing Blueprint & Isometric Drawing Reading 5

Question 1

At a scale of 1/8" = 1'-0", a line measures 2-1/2 inches. What length does it represent?

Accepted Answer

20 ft

Answer

2.5 ÷ 0.125 = 20 feet.

Question 2

Using an engineer's scale of 1" = 20', a site utility line measures 3 inches. What is its length?

Accepted Answer

60 ft

Answer

3 inches × 20 ft per inch = 60 ft.

Question 3

A 40-foot building drain is installed at 1/8" per foot slope. What is the total fall?

Accepted Answer

5 inches

Answer

40 × 1/8" = 5 inches of fall.

Question 4

What is the purpose of a north arrow on a site or floor plan?

Accepted Answer

Orient the drawing to true or plan north

Answer

The north arrow orients the sheet so you can relate it to the site and other drawings.

Question 5

What is a benchmark or datum on a civil or site drawing?

Accepted Answer

A fixed reference elevation used for measuring heights

Answer

A benchmark gives a known elevation from which sewer inverts and grades are referenced.

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