Type II — medium, high and very high-pressure appliancesDifficulty 4/5
A non-major repair will be made to a high-pressure appliance, and it will not be evacuated to the atmosphere afterwards. What must be reached before opening it?
- AThe full Table 1 vacuum level, because the appliance operates at high pressure
- BA pressure no higher than twenty-five millimetres of mercury absolute pressure
- CA pressure no higher than zero psig, rather than the Table 1 vacuum level
- DA pressure no higher than five psig, rather than the Table 1 vacuum level
Show answer and rationale
Correct: C. Section 82.156(a)(1)(i) creates this shortcut for medium-, high- and very high-pressure appliances. It applies only when the repair is not major and the appliance will not later be evacuated to atmosphere.
- D — Five psig is the figure specifically for oil changes under 82.156(a)(1)(iii).
- A — Table 1 is displaced by this provision when both of its conditions are satisfied.
- B — Twenty-five millimetres of mercury absolute is the low-pressure appliance requirement.