The low air warning device must activate by the time that tank air pressure falls to
- 80 psi.
- 100 psi.
- 90 psi.
- 60 psi. ✓
Answer: D. 60 psi.
The low-air warning device must activate when tank air pressure falls to 60 psi.
Why this is the answer
The handbook says the low-air warning must activate when air pressure is less than 60 psi, and that it must activate when pressure in any reservoir falls below 60 psi. It also notes that many systems bring the warning on above 60 psi, but that does not change the required threshold stated for the warning device. So the pressure listed as the required activation point is 60 psi.
Why the other answers are wrong
- A. 80 psi. — The passages never name 80 psi as the required activation point; they set the warning threshold below 60 psi, with some systems warning earlier.
- B. 100 psi. — The passages never name 100 psi as the required activation point; they set the warning threshold below 60 psi, with some systems warning earlier.
- C. 90 psi. — The passages never name 90 psi as the required activation point; they set the warning threshold below 60 psi, with some systems warning earlier.
Remember it
Remember the low-air warning as a 60 psi alarm: when pressure drops below 60, the warning must come on.