Service Equipment

EPA 608 Type 1 Chapter 9 (Take full course for free)

In this module, we will take a look at the requirements for equipment we use in servicing Type I appliances. We will discuss recovery devices, process tubes, vacuum pumps, and charging cylinders. Skip to quiz!

1. Recovery Device

Recovery devices are used to remove refrigerant from an appliance and store it in a recovery cylinder. They do the work of removing the refrigerant from an appliance, but they are not used for holding the refrigerant. Recall that recovery devices are used in active recovery or self-contained recovery.

Recovery devices need to be tested to ensure they meet EPA requirements. The EPA approves two organizations to certify recycling and recovery equipment:

• AHRI (the Air-Conditioning, Heating, and Refrigeration Institute), and

• UL (the Underwriters Laboratories).

AHRI Standard 740 describes the requirements that recovery equipment must fulfill. The recovery devices are tested according to this standard at EPA approved laboratories.

If equipment is properly certified, you will see a label on new equipment that states: “This equipment has been certified by AHRI/UL to meet EPA's minimum requirements for recycling and/or recovery equipment intended for use with [appropriate category of appliance].”

Recovery devices used with small appliances must be able to achieve either

• a 4 inch vacuum per AHRI 740, or

• recover a required percentage of refrigerant.

That means if the recovery device cannot achieve a 4 inch vacuum per AHRI 740, it must

• Recover 90% of refrigerant with a working compressor, and

• Recover 80% of refrigerant with non-working compressor

2. Process Stub

Service apertures or process stubs make it easier for technicians to access refrigerant to recover or to recharge the device. All appliances containing ozone depleting substances (ODS) and their “non-exempt substitutes” must have a service aperture or process stub.

In small appliances, the process stub that allows us to access the appliance’s refrigerant will look like a straight piece of tubing. This can be accessed using a piercing access valve.

The process stub makes it more accessible to use a piercing access valve to service the appliance. Large equipment does not need this stub because larger equipment cannot be pierced for an access valve and will generally be manufactured with access ports.

3. Vacuum Pump

Vacuum pumps are used to remove air and non-condensables from the appliance after the refrigerant in the appliance has been recovered.

They then vent the air and non-condensables into the atmosphere. Recall that air and non-condensables are not subject to the Venting Prohibition, only refrigerants — that’s why they can be vented.

Vacuum pumps are not designed to work with pressurized systems or containers and cannot be used as recovery devices.

4. Charging Cylinder

A charging cylinder is a refrigerant cylinder used to charge refrigerant into small systems with charges of up to a few pounds. You have to fill these cylinders with refrigerant to then use them to charge small systems. Think of them like portable gas tanks you might have in your vehicle that are filled with spare gas.

These cylinders used to be used for R-12, R-22 and other older refrigerants. The marks provided on the cylinders correspond to the volume of specific refrigerants so you would have to get a charging cylinder for each different refrigerant.

When filling a charging cylinder with ozone depleting substances, the refrigerant that is vented off the top is subject to the Venting Prohibition and needs to be recovered.

Charging cylinders are rarely seen on the field anymore because they have been replaced with digital scales, which are more portable, more accurate, and more universal.

5. Conclusion

In this module, we learned about different pieces of equipment used in our services as HVAC technicians. Remember that recovery devices need to be certified by EPA approved organizations. This means only AHRI and UL.

Remember also that:

• Process stubs on small appliances look like a straight piece of tubing

• Vacuum pumps cannot be used to recover refrigerants, and

• Any ODS and non-exempt substitutes must be recovered to not violate the Venting Prohibition

Question #1: All recovery devices need to be tested at a place called AHRI Standard 740.

1. True

2. False

Scroll down for the answer...

False!

AHRI Standard 740 lists the requirements for recovery device. It is a set of guidelines, not the name of a place where the devices are tested.

Question #2: Recovery devices are tested and certified by:

1. AHRI only

2. ASHRAE only

3. Both AHRI and UL

4. AHRI, UL, and the EPA

Scroll down for the answer...

Both AHRI and UL

AHRI and UL are the only two organizations approved by the EPA that certify recovery machines.

The EPA approves organizations to certify recovery machines, but it does not test and certify machines itself.

Question #3: If a recovery device cannot achieve a 4 in vacuum, which one of the following does it have to be able to do in order to be used with Type I small appliances? (Select all that apply)

1. Recover 80% of refrigerant with a working compressor

2. Recover 80% of refrigerant with a non-working compressor

3. Recover 90% of refrigerant with a working compressor

4. Recover 90% of refrigerant with a non-working compressor

Scroll down for the answer...

Recover 80% of refrigerant with a non-working compressor

Recover 90% of refrigerant with a working compressor

A recovery device must be able to achieve a 4 in vacuum or recover 80% of refrigerant with a non-working compressor and 90% of refrigerant with a working compressor.

We need to pay attention to whether the compressor is working or not working. If the compressor is working, the recovery device must recover a higher percentage of refrigerant.

This is because if the compressor is working, it should be able to recover more refrigerant.

Question #4: A recovery device has to achieve a 4 inch vacuum in all circumstances.

1. True

2. False

Scroll down for the answer...

False!

If the recovery device cannot achieve a 4 inch vacuum, it has to either:

• Recover 80% of refrigerant with a non-working compressor, or

• Recover 90% of refrigerant with a working compressor.

Question #5: What does the process stub look like in small appliances?

1. A straight piece of tubing

2. A straight piece of wiring

3. A round piece of tubing

4. None of these

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A straight piece of tubing

The process stub on small appliances looks like a straight piece of tubing.

Question #6: Vacuum pumps can be used to

1. Recover refrigerant

2. Remove air and other non-condensables

3. Release refrigerant into the atmosphere

4. Both (a) and (c)

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Remove air and other non-condensables

Vacuum pumps are used to remove air and other non-condensables only after all refrigerant has been recovered.

Vacuum pumps cannot be used to recover refrigerant.

Question #7: The refrigerant vented off the top of charging cylinders needs to be recovered if it is:

1. An ozone depleting substance like HCFC

2. An HFC

3. A non-exempt substitute

4. All of these

Scroll down for the answer...

All of these

All refrigerants subject to the Venting Prohibition need to be recovered when vented off the top of charging cylinders.