A chiller's rupture disc has to be replaced after it relieved. What does that job require before the disc comes off?
Correct Answer
D) Recovery of the charge to the required level, because the disc is part of the refrigerant boundary
A rupture disc is fitted directly to the pressure vessel and forms part of the refrigerant boundary. Taking it off opens the appliance to the room, so the charge has to be recovered to the required level first with certified equipment. The replacement is the rating the manufacturer specifies, and the relief piping beyond it has to be left clear. A machine whose disc has relieved has usually lost its charge already, but that has to be verified rather than assumed.
Why This Is the Correct Answer
The disc is a component of the pressure vessel, and removing it opens the refrigerant circuit exactly as removing a valve or a cover would. The evacuation requirement therefore applies, and the technician gauges the machine first rather than assuming the relief event emptied it. The new disc matches the manufacturer's specified rating.
Why the Other Options Are Wrong
Option A: Nothing beyond isolating the relief piping, because the disc sits outside the pressure boundary
The disc is part of the pressure boundary, not an accessory beyond it, which is why the machine has to be empty before it comes out.
Option B: A hydrostatic test of the shell, because the vessel has been exposed to an overpressure event
Hydrostatic testing of a chiller shell is a specialized procedure and is not a routine requirement after a disc has relieved.
Option C: A written variance from the owner, because relief devices are outside the technician's scope
Relief device replacement is ordinary chiller work, and no variance from an owner has any effect on the refrigerant requirements.
Memory Technique
The disc is the wall, not the window. Taking it out is opening the machine.
Reference Hint
Recovery to the required level is required before opening any part of the refrigerant boundary, including a relief device.
More epa-608-type-3 Questions
Some jobs on a chiller count as a major repair under the refrigerant rules, which changes what a technician is allowed to do with a badly leaking machine. Which job falls into that category?
An owner asks how many pounds of refrigerant the rules allow to be left inside a chiller once the recovery has been signed off. What is the correct answer to give him?
The motor of a hermetic centrifugal chiller sits inside the pressure boundary rather than outside it on a shaft. What follows from that construction?
An oxygen monitor is used to decide whether a chiller machine room is safe to enter after a refrigerant release. Below what oxygen reading is the atmosphere treated as oxygen deficient?
A low-pressure chiller's rupture disc has a discharge line running from it. Where does that line have to terminate?
A refrigerant vapor detector in a chiller machine room reaches its alarm level. Besides sounding, what is that alarm expected to do?
Which piece of equipment requires a technician to hold Type III certification before it may be serviced?
What property of the refrigerant is what actually places an appliance into the low-pressure category?
During normal operation, what condition exists inside the evaporator of a running low-pressure centrifugal chiller?
In what unit is the required final recovery vacuum for a low-pressure appliance normally expressed?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
In what order does a technician remove the charge from a low-pressure chiller to keep the job from dragging on?
Next Question
A chiller is fitted with a factory pump-out unit and a storage tank, and the entire charge is now sitting in that tank. What still has to be done before the machine's waterbox covers come off?