questions and answers 2025
What should be done to reduce refrigerant loss from a purge unit on a R-123 chiller? - ANSWER
Repair the leak in the system
To raise the pressure of a low-pressure refrigeration system for leak checking, you can -
ANSWER Heat the system by circulating hot water, raising the temperature of the room, or using
heating blankets
Low-pressure systems must be evacuated to - ANSWER 25 mm of Hg absolute before being
discarded.
Purge units are required on low-pressure chillers because? - ANSWER these systems operate
below atmospheric pressure.
What is the safety classification of R-123 - ANSWER B1
hydrostatic tube test kit is used to? - ANSWER find leaks in the tube.
What is a valid reason to request an extension from the EPA on the appliance leak repair
deadline? - ANSWER Local permit regulation make the repair within 30 days impossible AND
more time is needed to obtain the necessary repair parts from the manufacturer.
For low pressure chiller, it is best to begin refrigerant recovery with ______ removal to avoid
freezing of the water in the chiller barrels - ANSWER liquid.
Every recovery and recycling unit must be _____________. - ANSWER labeled as certified to
meet EPA's requirements
, The best method to determine a chiller's normal charge for leak rate calculations is to - ANSWER
use the charge stated on the equipment nameplate.
What safety precautions should be adhered to for low-pressure systems? - ANSWER Use gloves
and safety goggles when working with liquid refrigerant.
If possible, the temperature of the equipment room where the chiller is located ______. -
ANSWER Should be increased to speed recovery
To prevent freezing, when recharging an evacuated water-cooled chiller system with R-123, first
charge with vapor to a pressure of at least _______________. - ANSWER 20 in Hg vacuum
When evacuating a system and the freezing of moisture in the system is preventing you from
achieving a deep vacuum, it may be necessary to prevent freezing by - ANSWER increasing the
system pressure with nitrogen
The typical design burst pressure for a rupture disk on a low-pressure centrifugal air-
conditioning system is ______________ . - ANSWER 15 psig
A water-cooled recovery unit typically has a _________________. - ANSWER lower recovery
tank pressure and therefore faster recovery rate
The owners and operators of any system that has 50 or more pounds of refrigerant charge must
keep records of refrigerant added, leak inspections, initial verification tests, and follow-up
verification tests for at least _______. - ANSWER 3 years
The saturation pressure corresponding to 32 °F for R-123 is - ANSWER 20 inches of HG vacuum