Transcript Slide 1

Maytag Services
Refrigerant Handling
Standard Operating Procedures
1
Federal EPA Refrigerant
Recovery Guidelines
Licensing Requirements
• Under section 608(c) of the 1990 Clean Air Act
Amendments, “… ( It is )unlawful for any person, in
the course of maintaining, servicing, repairing or
disposing of an appliance…. to knowingly vent or
otherwise knowingly release or dispose of any Class I
or Class II substance used as a refrigerant in such an
appliance in a manner which permits such substance
to enter the environment… “
• The Act further establishes that any technician that
can be reasonably expected to enter a sealed system
during the course of repair of a refrigeration
appliance must be certified in refrigerant handling by
a Federal EPA approved certification organization.
EPA Penalties
• A willful release of refrigerants or failure
to follow EPA recovery guidelines
carries stiff penalties for the technician
– $30,000 per occurrence
– Up to 5 years jail time
• EPA offers a $10,000 reward to anyone
reporting a violation
Certification Classifications
There are 4 certification classifications:
• Type I- Allows technicians to perform service on
refrigeration equipment containing less than 5 lbs. of
refrigerant.
• Type II- Allows technicians to work on refrigeration
equipment containing more than 5 lbs. but less than
50 lbs. of refrigerant.
• Type III-Allows a technician to work on refrigeration
equipment containing more than 50 lbs. of refrigerant
• Universal- Allows a technician to work on any
refrigeration equipment, regardless of the amount of
refrigerant.
Certification Guidelines
• Type I or Universal certification is required to
work on residential refrigeration appliances.
Type II and Type III certifications do not
permit working on small appliances.
• Technicians are required to have valid
certification cards on their person anytime
that they are performing repairs on a
refrigeration system.
EPA Restrictions
• Purchase of refrigerant is restricted to certified
technicians and Section 608(c) certified technicians
can only purchase refrigerant in 30 lb. (minimum)
containers.
• Recovery of refrigerants must be accomplished with
an EPA approved recovery device. Two types of
recovery devices are allowed.
– Active- a recovery pump that is able to pull a system into a
minimum 4” vacuum.
– Passive- a non powered device capable of capturing 80% of
the system charge (such Recovery bag)
EPA Restrictions
• Use of refrigerant recovery bags, such as the
Whirlpool Ozone Saver® Bag, is regulated by the
EPA. Compliance requires:
– The technician must recover a minimum of 80% of the
system charge. On a non working compressor, the base of
the compressor must be heated and struck sharply with a
hammer to free any refrigerant trapped in the compressor oil.
– Recovery bags are designed as temporary refrigerant
storage devices and should be removed from vans each
night.
– The bag can only be used 4 times before it is discarded.
– The bag must be emptied within 48 hours
– Torn or damaged bags must be discarded.
Recovered Refrigerant
• All Refrigerants must be recovered and
reclaimed
• Mixed refrigerants cannot be reclaimed
and must be destroyed
– Some refrigerants (R-12, R-134a) have value on
the reclaim market.
– Every pound we have to destroy not only costs us
$3-4 per pound to dispose of but we miss out on
the reclaim income that would have been
generated
Other EPA Recommendations
• All leaks should be located and repaired
• All hoses and manifold gauge sets must
utilize low loss fittings
US Department Of
Transportation (DOT)
Guidelines
Material Safety Data Sheets (MSDS)
• Technicians are required to carry MSD
Sheets for every type of chemical in
their truck, including acetylene, oxygen,
glues, cleaners and refrigerants.
– Technicians should read and follow all
recommended safety guidelines when
handling refrigerants and other chemicals.
Transportation of Refrigerants and
other Compressed Gasses
• Refrigerant, acetylene, oxygen, nitrogen, etc. are all
considered to be hazardous materials by US DOT.
Shipping of these containers is highly regulated.
– Before shipping any of these items by common carrier,
check with the carrier to determine packaging and Bill of
Lading requirements.
– Air freighting of these items is strictly prohibited.
• All compressed gasses such as refrigerant,
acetylene, oxygen, aerosol and paint cans, etc. must
be in DOT approved containers and secured in the
van with chains or other significant restraints to
prevent containers from falling over, rolling around in
the truck, etc.
Transportation of Refrigerants and
other Compressed Gasses
• All cylinder valves should be completely
closed and OXY/Acetylene regulators
removed whenever a cylinder is being
transported
• All cylinder must completely shut-off
with no leaks
Transportation of Refrigerants and
other Compressed Gasses
• The acetylene cylinder must not have
been fully closed and a small leak
occurred
• On the Monday morning when the van
door was opened, a large explosion
took place.
• Tech suffered damage to his ear drums
and face.
Maytag Services Shipping Paper
Technician Name:__________________________
Chemical
Service Vehicle #_____________________________________
Cylinder sizes
# of Partially Filled
# of Full Cylinders
Cylinders
Acetylene, Dissolved
Chlorodifluoromethate (R-22)
Dicholorodifluoromethane (R-12)
Tetrafluoroethane (R-134a)
Oxygen, compressed
Nittrogen, compressed
Directions:
Under Cylinder sizes, list the size of the cylinders carried for the chemical in question (I.e. 2#, 30#, 50#)
Under # of Partially filled cylinders, list how many of the cylinders are partially filled
Under full cylinders, list how many of the cylinder are full
Example
Acetylene, Dissolved
2#, 5#
1
1
Transportation of Refrigerants and
other Compressed Gasses
• Transporting refrigerant in charging cylinders
(such as Dial-a-Charge) is not permitted.
Charging cylinders must be empty of
refrigerant before transporting.
• Some states go as far as requiring that
refrigerant be removed from self sealing
hoses on compound gauges. To assure
compliance, technicians should be sure to
recover refrigerant from gauges before
transporting.
Cylinder Safety
• New refrigerant is packaged in DOT 39
disposable cylinders. When empty, these
cylinders must be disposed of properly. After
evacuating the cylinder (to 0 PSIG), the valve
must be removed. The tank can then be
disposed of with other metal waste.
• Reuse of DOT 39 disposable cylinders (such
as storing or carrying compressed air) is
illegal and carries a penalty of $25,000 and
up to 5 years in prison.
Cylinder Safety
• Recovered refrigerant can only be stored in
DOT approved recovery cylinders (with the
exception of temporary storage in a
refrigerant recovery bag.)
• US DOT regulates that recovery cylinders
must not be filled beyond 80% capacity.
– Many of these tanks are equipped with a ball or
float switch that, when connected to a recovery
pump, will shut the pump off when the 80% mark
on the tank is reached.
Cylinder Safety
• If the cylinder is not equipped with a ball or float
switch, the tank must be weighed prior to each
recovery to insure that it can accept additional
refrigerant. Cylinders are marked with their empty or
tare weight (TW) and water content weight (WC).
This represents the total weight of the cylinder and
contents when the cylinder is filled to capacity.
• Sometimes the tank is marked with the tare weight
and the “MAX. Gross WT ___ LB.” The max weight,
again, represents the total weight of the cylinder
when it’s filled to capacity.
Cylinder Safety
• To insure that the recovery tank is not filled
beyond 80%, the technician must determine
the max fill level for each tank. To do that, the
technician must compute the WC weight (if
not listed) and multiply by .8
• Example:
 MAX weight= 23.5 lbs, TW= 10.5 lbs.
 Max WC weight= 13 lbs. (23.5-10.5)
 Maximum refrigerant that can be put into tank=
10.4 lbs. (13 lbs. WC X 80%)
Cylinder Safety
• Overfilled cylinders present a serious safety
hazard. Because liquids don’t compress, any
rise in temperature can cause an over filled
tank to explode. Technicians must avoid
overfilling or exposing a tank to extreme
temperatures.
– In the summer, park in the shade whenever
possible
– If the truck is equipped with vents, open them
– Never use an open flame to heat a refrigerant
cylinder
Hydrostatic Cylinder Testing
• Recovery cylinders must be hydrostatically tested
every five years. The last test date will be stamped
or embossed on the shoulder of the cylinder. In most
cases, the tank will clearly be marked with the first
retest date. For example,
FIRST RETEST DATE
06 07
RETEST EVERY FIVE YEARS
• This means that the tank must be submitted for
testing prior to June of 2007 and every five years
after that (on or before the month of June).
Hydrostatic Cylinder Testing
• Older tanks may have the date
stamped on them in the pattern shown
to the right. This stamp indicates the
last retest date and the testing
organization that completed the test.
• In this example, this cylinder was last
tested on May of 2002 by tester A253.
The next retest date, therefore, is May
of 2007.
A2
05
02
53
Hydrostatic Cylinder Testing
• Technicians carrying tanks that are
beyond the required test date must
discontinue use of the cylinder
immediately.
– Filling of cylinders with expired test dates is
prohibited.
– Any tank that has an expired test date
must be submitted to a reclaimer for
refrigerant processing and cylinder testing.
Labeling of Refrigerant Cylinders
• All refrigerant cylinders, both new and
recovered, must be properly labeled with their
content.
– If the recovery cylinder is in its original cardboard
carton, there are boxes printed on the carton that
allow placing an X or a √ mark next to the type of
refrigerant that is being carried.
– If out of the carton, most refrigeration supply
houses supply stickers and/or tags that can be
affixed to recovery cylinders to identify the
contents.
Contaminated Refrigerants
• Normal contaminants, such as air, refrigerant oil and
water that are mixed with refrigerants in a recovery
cylinder are not an issue. Care should be taken,
however, to insure that no other contaminants are
added to the refrigerant.
• If a reclaimer suspects that a refrigerant tank is
contaminated with unidentified chemicals, regulations
require that the contents of the tank be analyzed and
the refrigerant be disposed of. Reclaimers charge a
fee for this service.
Mixed Refrigerants
• Mixing of refrigerants should be avoided.
– Refrigerants are considered to be mixed when
more than 3% of a second refrigerant is added to
the base refrigerant. For example, adding 1 lb of
R-22 to a cylinder that contains 20 lbs of R-134a
will render the entire tank as mixed.
– Mixed refrigerants cannot be easily or
economically reclaimed and thus, must be
destroyed. Instead of the usual $25 or $30
handling fee for accepting used refrigerant, the
price to dispose of mixed refrigerants can exceed
$100 per cylinder ($3-4 per pound).
Tracking of Refrigerant Usage
and Recovery
• The Federal EPA has the ability to subpoena
refrigerant usage records of an individual
and/or a company to compare refrigerant
purchases against recovery levels.
– Since the minimum recovery level for any system
is 80%, a discrepancy between refrigerant
purchased and refrigerant recovered could
indicate that technicians are not recovering at
mandated rates.
– Technicians must maintain logs to track refrigerant
usage
Refrigerant Tracking Log
Technician____________________________________
Customer Last Name
Address
Serv. Ticket #
Refrigerant
Recovered
Oz.
Recvrd
Refrigerant
Oz.
Installed
Used
R-134a
R-134a
R-22
R-22
R-12
R-12
Other
Drop-in
R-134a
R-134a
R-22
R-22
R-12
R-12
Other
Drop-in
R-134a
R-134a
R-22
R-22
R-12
R-12
Other
Drop-in
R-134a
R-134a
R-22
R-22
R-12
R-12
Other
Drop-in
R-134a
R-134a
R-22
R-22
R-12
R-12
other
Drop-in
Comments
Directions: Track all refrigerant usage. Place √ next to refrigerant recovered or installed. Use comment area to denote discrepancies between amount
used and amount recovered. I.e. System leak, system flat.
Refrigerant Handling Process
Required Equipment
• Over the next few months, each White Goods
technician will be supplied whatever equipment
they’re missing to insure they all have:
–
–
–
–
–
–
–
–
–
–
Scale
R-134a Charging Cylinder
R-134a Manifold Gauge set
Recovery pump
30 lb. recovery cylinder
Electronic Leak Detector
Hand valves (2)
Process tube adapter kit
Pinch off pliers
Recovery Bags (2)
Required Equipment
•
Over the next few months, each “specialty” technician will be supplied
whatever equipment they’re missing to insure they all have:
–
–
–
–
–
–
–
–
–
–
–
–
–
Scale
R-134a Charging Cylinder
R-134a Manifold Gauge Set
CFC Manifold Gauge Set
Micron Gauge
Recovery pump
Vacuum pump
30 lb. recovery cylinder
Electronic Leak Detector
Hand valves (2)
Process tube adapter kit
Pinch off pliers
Recovery bags (2)
Required Equipment
• Over the next few months, each PTAC** technician
will be supplied whatever equipment they’re missing
to insure they all have:
–
–
–
–
–
–
–
–
–
–
Scale
CFC/HCFC Manifold
Vacuum Pump
Micron gauge
Recovery pump
30 lb. recovery cylinder
Electronic Leak Detector
Hand valves (2)
Process tube adapter kit
Pinch off pliers
**PTAC techs who also
work on White Goods
will also carry R-134a
refrigerant and related
tools
Refrigerant Handling Process
• Virgin refrigerant
– Technicians serviced by land based currier
will continue to receive new refrigerant
from RPDC
– Technicians serviced by air currier must
purchase refrigerant locally. (Use Refron
facilities when possible to get quantity
preferred pricing)
Refrigerant Handling Process
• Used refrigerant
– Technicians serviced by land based currier
will return full cylinders to RPC
• RPC will replace with empty, clean cylinder
– Technicians serviced by air currier must
find local parts supplier that is willing to
accept used refrigerant
• Work with virgin refrigerant supplier
• Set up cylinder exchange program
Bag vs. Pump
• Use recovery pump and tank on all Major
Brand refrigeration that
– can be swept
– uses R-134a
• Use the bag when servicing systems with
– Burnouts
– Unknown refrigerant
– Drop-in refrigerant
Bag Handling Process
• Technicians serviced by land based currier
– Return bags to RPC with tag identifying contents as
• Unknown refrigerant
• R-134a Burnout
• R-22, MP-39, etc
– RPC will replace with empty, clean bag
• Technicians serviced by air currier
– Transfer contents of bag to a cylinder every night
•
•
•
•
R-134a burnouts to R-134a tank
R-22 to R-22 tank
If enough R-410 is encountered, R-410 to its own cylinder
All other refrigerants to “mixed refrigerants” tank
RPC refrigerant handling
• Each RPC responsible to
– Maintain supply of empty tanks on hand to
replenish tanks when a full tank is received
– Empty bags within 24 hours into appropriate
recovery tank
•
•
•
•
R-134a
R-22
R-410
All other refrigerants to “mixed refrigerants” tank
Approved Sealed System
Repair Process
Why Change to Sweep
• Vacuum pumps require constant maintenance
– Oil changes every 3 or 4 normal evacuations
– After processing every burnout
– Dirty oil renders pump incapable of pulling system to
required vacuum levels to assure complete dehydration
• Without ability to gauge dehydration level, there is no
way to gauge how effective a vacuum was pulled,
even with a well maintained vacuum pump
• Properly performed sweep superior to deep
evacuation with poorly maintained pump or without
measuring micron levels in system
Why is proper dehydration important?
•In order for water to boil
at normal room
temperatures, system
pressure must be
dropped below 27”
vacuum (About 3,000
Microns or less)
Temperature
Pressure Affect on Boiling Point of Water
334
284
234
184
134
84
34
•Vacuum must be held
over system until Micron
levels drop below 300
microns
PSIG
29.92 in Hg
19.74
11.6
0
in Hg
in Hg
PSIG
1.4 PSIG
5 PSIG
10 PSIG
15 PSIG
•Depending on pump
conditions, proper
dehydration could take
several minutes or
several hours.
Unless system pressure is dropped to 300 microns or less, there is still water left in the system.
What happens when water is left in the system?
•Moisture and refrigerant create acids
•Acids eat away at compressor winding insulation
•Acids and oil create sludge which plugs cap tubes
Why is proper dehydration even more
important with R-134a?
• R-134a systems do not mix well with with mineral
oils and require the use of Ester oils
• Ester oil are hygroscopic, meaning that they have a
great affinity for moisture (actually pull and absorb
moisture out of the air)
– Ester oils are made from acids that have been dehydrated
– When exposed to atmospheric moisture, the oil actually pulls
vapor out of the air
– The airborne moisture combines with the ester oil and
returns it to its original acidic state
– Acids eat away at the compressor windings
– Acids combine with R-134a to form salts and gels which can
plug the capillary tube.
• Moisture in the system will eventually destroy the
compressor (not a matter of if but when)
Why Change to Sweep
• Sweep has been used in the industry for over 30
years (Maytag, GE, Whirlpool, Sears, Montgomery
Wards and a slew of independents)
• Over the 30 year period, no conclusive proof has
ever surfaced that sweep results in any more repeat
failures than deep evacuation
• In fact, laboratory testing has shown that a properly
performed sweep is superior to deep evac that is
performed with poorly maintained vacuum pump or
without an accurate method of measuring
dehydration levels in system
Processing R-134a systems
• R-134a requires dedicated equipment to
prevent cross contamination
• R-134a systems should not be open to
the atmosphere for longer than 20
minutes (max)
• Verify compressor is nitrogen charged
• Keep plugs in compressor until ready to make
final connections to system tubing
Processing R-134a systems
• Low side leaks
– Find and repair leak
– Replace compressor and dryer
• High side leaks
– Find and repair leak
– Replace drier
• Compressor burnout
– Flush system
– Replace compressor and drier
Processing R-134a systems
• Because of the small system charges of
modern refrigerators, accurate charging
is critical
– On a 5 oz. system, overcharging by ½ oz.
results in 10% overcharge
• Because of energy and cooling capacity
issues, it’s better to be slightly
undercharged than to be overcharged
by any amount.
Affect of Over/Undercharge on 950 BTU
Compressor
BTU’s
Amp
Draw
(Cooling
Efficiency)
1000
1.4
950
1.3
900
1.2
850
1.0
800
.9
750
.8
700
.7
650
.6
600
.5
75
80
85
90
95
100
Percent Correct Charge
105
110
115
Problem with using a scale to charge
small systems
• One quarter ounce resolution could undercharge
or overcharge a system by as much as 10- 20%
(depending on system charge)
• Unless scale is calibrated on a regular basis, there
is no way to determine accuracy of scale
• Movement of the cylinder during charging
changes the reading on the scale and could cause
the final charge to be off by as much as 50%
Adding system charge
• Use Dial-a-Charge for
all R-134a products.
• Charging scales should
be used for
– Drop-ins
– R-22
– To weigh recovery
cylinders if cylinder is not
equipped with a ball float
valve
Approved Sealed System Process
• Sweep charge is the only approved method
of refrigerator and freezer system processing
for most product lines
– Exceptions
• PTACS
• Samsung 4 drawer side by side
• Refrigerator technicians will need to turn in
their vacuum pumps
Note: Vacuum pumps will be re-allocated to
commercial and specialty techs
Sweep Charge
Sweep Charge Steps
1.
2.
3.
4.
5.
Reconfirm need for the sealed system repair
Verify that new compressor is nitrogen charged
(should hear a pop when line plug is removed from
compressor)
Reinstall plugs on compressor to prevent excess
air from entering system while old compressor is
removed from the system
Attach temporary line taps to low side and drier
process stubs
Attach gauges and recovery pump. Recover
refrigerant per pump manufacturer’s recommended
procedures
Sweep Charge Steps
6.
7.
8.
Cut out and remove old compressor
Install new drier
Install and plumb new compressor in place (keep
compressor tubes plugged until ready to attach to
system. This will assure that the system does not stay
open longer than the recommended 20 minutes.)
9. Attach process stub adapters to new compressor and
drier process stubs
10. Reattach gauges. High and low side hoses should
have hand valves attached at end of each hose
Sweep Charge Steps
11. Fill Dial-a-Charge with system charge plus 8 oz.
and heat refrigerant until pressure on Dial-aCharge is 30 lbs. over ambient. Remember to
capture refrigerant if bleeding of the cylinder is
necessary (EPA reg)
12. Attach Dial-a-Charge to common hose on manifold
gauge set.
13. Purge air out of all hoses and pre-charge high side
hose with liquid.
14. Charge 4 oz of refrigerant into the system using the
hand valve at the end of the high side hose to
meter the refrigerant into system.
Sweep Charge Steps
15. Check all joints for leaks with a mirror and
electronic leak detector
16. Turn compressor on and allow charge to circulate
for 5 minutes
17. Close hand valve at drier
18. Reattach pump and recover sweep charge as a
liquid from the drier process stub while the
compressor is running.
19. Continue to run recovery pump until the system is
down to the pump design pressure (usually around
20 inch vacuum on most pumps)
Sweep Charge Steps
20. Close hand valve at drier and turn off compressor
and pump
21. Recheck pressure on Dial-a-Charge to make sure it
is still at 30 lbs. over ambient. Reheat if necessary
22. Disconnect pump and reattach Dial-a-Charge to
center hose of gauge set
23. Purge hoses and pre-charge high side hose with
liquid
24. Using the hand valve, meter system charge into the
system Important: Once the charge is added and
the hand valve is closed, DO NOT reopen.
Sweep Charge Steps
25. Using pinch off pliers, pinch off the high side
process stub.
26. Remove the hand valve and process tub adapter
and braise the stub shut
27. Repeat process with low side process stub
28. Check for low side leaks.
29. Restart the compressor and check high side for
leaks.
30. Check current draw and feel compressor discharge
for heat movement. Check air supply in freezer. If
air is cold and current draw is normal, repair was
successful.
R-12 and Replacements
Processing R-12 Systems with
Drop-in Refrigerants
• MP-39 only approved R-12 substitute
– Hot Shot should not be purchased or used due to safety
concerns (flammable- contains 6% methane)
• As with all blends, the sweep and final charges of
MP39 must go into the system as a liquid
– Requires that refrigerant be heated to 30 lb. over ambient
• If no heater blanket available for MP-39 tank, tank can be
submersed into a partially filled 5 gallon bucket of warm water.
• Water should be no hotter than your skin can tolerate (125º F)
– Charge must go into high side to prevent slugging of
compressor
• Some older refrigerators have direct suction pumps and adding
liquid to low side could dump refrigerant into compression
chamber