Why must the hot water used to pressurize an R-11 chiller for a leak test be controlled?
Safety · EPA 608 Type III. The correct answer, and the reasoning behind it.
ASHRAE Standard 15 equipment-room requirements and refrigerant sensors.
The question
Why must the hot water used to pressurize an R-11 chiller for a leak test be controlled?
- Too much heat could raise pressure past the rupture disc settingCorrect answer
- Hot water can cause the R-11 to ignite
- Hot water dissolves the tube coatings
- Hot water turns R-11 into a toxic decomposition gas above about 100 °F
Why “Too much heat could raise pressure past the rupture disc setting” is correct
Warming the refrigerant raises its pressure, and overheating it can raise the pressure past the rupture disc and release the charge. That is why EPA's topics speak of controlled hot water and why the test pressure is held at or under 10 psig.
Source: EPA: Test Topics; Trane CVHE-SVX005E-EN, CenTraVac IOM (15 psig rupture disk)
Why the other answers are wrong
- Hot water can cause the R-11 to ignite — R-11 is not flammable.
- Hot water dissolves the tube coatings — The concern is refrigerant pressure, not tube coatings.
- Hot water turns R-11 into a toxic decomposition gas above about 100 °F — R-11 does not decompose at hot-water temperatures.
Practice more of this
More EPA 608 Type III practice questions, or see every EPA 608 practice test.
Unofficial, not affiliated with the EPA or any EPA-approved certifying organization. Questions are original practice written from public EPA material, not real exam questions.