Type II — medium, high and very high-pressure appliancesDifficulty 4/5
A high-pressure appliance holds a full charge of 260 pounds and the recovery machine was made in 2018. What evacuation level does Table 1 require?
- AFifteen inches of mercury vacuum, because the recovery machine postdates the rule
- BZero inches of mercury vacuum, because high-pressure appliances have no requirement
- CTen inches of mercury vacuum, because the charge is two hundred pounds or more
- DFour inches of mercury vacuum, because the appliance operates at high pressure
Show answer and rationale
Correct: C. Table 1 splits high-pressure appliances at two hundred pounds. Under that figure the requirement is zero; at or above it the requirement is four inches for pre-1993 equipment and ten inches for later equipment.
- D — Four inches is the pre-15 November 1993 equipment figure; this machine was built in 2018.
- A — Fifteen inches applies to medium-pressure appliances of two hundred pounds or more.
- B — Zero applies only to high-pressure appliances with a charge under two hundred pounds.