Monday Test Flashcards
Pass
How can ice be removed from a sight glass
with alcohol spray
What must be done with badly corroded relief valves
replace them
Where can you find the allowable test pressure on a system
Unit Data Plate
Can Oxygen be used to check for leaks? If not why not?
No. Oxygen in the presence of oil under high pressure can be explosive
What is the likely result of heating a recovery cylinder with an open flame
The refrigerant inside will decompose into a toxic material, venting of refrigerant into the atmosphere or the tank may explore
What is the primary purpose of disposable cylinders?
For virgin refrigerants from the manufacturer
To what internal pressure should a disposable cylinder be reduced to for disposal?
0 PSIG
Should you ever use a disposable cylinder for refrigerant recovery
No
To dispose of a cylinder you should be sure all refrigerant is recovered and the cylinder is no longer usable. What else?
Puncture the container before disposal
For safety, refrigerant cylinders should not be rusted or damaged and always properly color coded. What additional step should also be taken with these cylinders?
Properly secured at all times
What is the proper color code for recovery cylinders?
Grey with a yellow top
What is the maximum percent by weight that a cylinder may be filled
80%
What can happen if a cylinder is overfilled
Hydrostatic pressure could cause the cylinder to explode
List 3 methods for measuring the fill level of a recovery cylinder?
Floats, thermistor type sensors, weighting scales
How often must reusable cylinder be hydrostatically tested?
every 5 years
Why must only refillable cylinders be used for transport
Federal code of regulations title 49
The clean air act phases out CFC/HCFC production and prohibits venting. What else does it require
Standards to be set for recovery of all refrigerants prior to appliance service and disposal
Falsifying or failing to keep required records, failing to reach required evacuation levels and knowinly releasing CFC or HCFC refrigerants are violations of the Clean Air Act. What activity with a substitute refrigerant is also a violation?
KNOWINGLY venting CFC and HCFC and their substances.
Which refrigerants must be recovered prior to opening a system?
All refrigerants as of November 15 1995
What releases of a CFC and HCFC are violations of the Clean Air Act?
Any KNOWINGLY vented refrigerants
On what date did it become illegal to vent CFC and HCFC
July 1 1992
Which appliances are covered by Section 608
Any device which contains and uses a class 1 or class 2 substances as a refrigerants and is used for household or commercial purposes.
What is the primary reason the EPA requires a service aperture or process stuff on all appliances
For adding or removing refrigerant from the appliance
The Montreal Protocol calls for the regulation of what chemicals
Ozone depleting compounds CFC HCFC and Halons
On what date was the importation and production of all CFC phased out?
In the US December 31 1995
Where will we get replacements?
Through recovery of existing refrigerants
What steps are called for by the Clean Air Act
Taxes on production and use, standards set for the recovery of refrigerants
What is prohibited by the Clean Air Act
Venting
Does Atmospheric Ozone help or hurt the work of the earths protective shield
It helps
What chemical in the statosphere tells us ozone depletion is occurring?
Chlorine-monoxide
How do we know the chlorine in the statosphere is coming from CFC?
the increase in chlorine and flourine matches the emmissions of CFC
How do we know CFC get to the statosphere
from high altitude air sampling measurements
What role does the ozone layer play in protecting the earth?
it blocks much of the harmful ultraviolet radiation UV-B
What are the effects from increase UV radiation
Skin cancer, cataracts, lowered human immunity
What are the effects of increased UV radiation on the environment?
timber growth is reduced, crop yields lowered, marine life and food chain are impaired.
What is the Montreal Protocol
A treaty that called for the reduction of production of CFCs
What is a ternary blend?
a blend of 3 different refrigerants
How should systems using blended refrigerants be charged?
in liquid for into the high side of the system
in there a drop in refrigerants for CFC-12
No
How do you leak check HFC134a system with a partial charge
recover the remaining refrigerant and pressurize with nitrogen add r22 so you can use a HCFC leak detector
What is the preferred oil to be used with HFC-134a
Ployolester
Can ester based oils be mixed with other oils
No
What lubricant is recommended for use with a ternary blend?
For HCFC Alkylbenze for HFC Ployolester or ester oil
Safety and butyl lined glves should be worn for what procedure
When operating recovery or recycling devices and when handling and refilling refrigerants cylinder
What is HFC
A fluorocarcon that contains no chlorine
Which refrigerants are HFC’s
R134a. 404a, 407C, 410a
What is the ODP of HFC
Zero
Which refrigerant have high ODP
CFC
Which refrigerants have low ODP
HFCF and HFC
Does R500 have a CFC
Yes
What precautions should be taken when recovering refrigerant from a system with multiple service valves
Insure that liquid is not trapped between service valves
What is different about any leaks in systems charged with a blended refrigerant?
Because they are blended the ingredients will leak at different rates
What purpose is served by heating a system during evacuation
to speed up moisture removal
What is the result of over evacuating a system
no damage will be done
When measuring the vacuum of a system being evacuated the system must be isolated. What must be done to the vacuum pump?
Valve it off and turn it off
How much ozone can chlorine atom destroy
100,000
What refrigerants are CFCs
R11,12,113,114
What refrigerants are HCFC
R22 R123
What is a material safety data sheet
a sheet that states the safety ratings and precautions to be taken for use and handling of chemicals
What safety classification within the ASHRAE standard is most safe
A1
What is caused by inhaling of refrigerant vapors
heart irregularities or Asphyxia