Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

10.6 - Type II Memorization Sheet

Module: Universal Review and Mock Examinations
Purpose: One-page-target rapid review of the highest-priority Type II facts before Universal mock examinations
Covers: Type II material consolidated from Sections 8.1–8.10
Regulatory verification basis: Current Module 8 material verified August 12, 2026
Use: Memorize the equipment scope, pressure categories, leak concepts, recovery sequence, evacuation table, major-repair rules, and Type II safety principles below; return to Module 8 when a condition or exception is unclear

1. Type II Scope

Type II certification covers covered:

MEDIUM-PRESSURE APPLIANCES
+
HIGH-PRESSURE APPLIANCES
+
VERY-HIGH-PRESSURE APPLIANCES

Common Type II Examples

  • Residential central split-system air conditioners.
  • Field-connected mini-splits and multi-splits.
  • Residential and commercial heat pumps.
  • Packaged rooftop units.
  • Walk-in coolers and freezers.
  • Remote commercial refrigeration systems.
  • Supermarket compressor racks.
  • Cold-storage systems.
  • Many industrial-process refrigeration systems.
  • Specialized very-high-pressure appliances.

Classification Boundaries

Small appliance
→ Type I

Low-pressure appliance
→ Type III

Passenger-compartment MVAC
→ Section 609

Qualifying MVAC-like appliance
→ Type II OR applicable Section 609 pathway

Medium / high / very high pressure
→ Type II

Exam Traps

Small charge
≠
automatically Type I

Large appliance
≠
automatically Type II

Commercial refrigeration
≠
automatically Type II

Pressure category and appliance definition control.

2. Refrigerant Pressure Categories

The current Section 608 pressure classifications use:

104°F

and:

psia

not psig.

Pressure CategoryClassification BasisType
Low pressureBelow 45 psia at 104°FType III
Medium pressure45 to 170 psia at 104°FType II
High pressure170 to 355 psia at 104°FType II
Very high pressureCritical temperature below 104°F, or saturation pressure above 355 psia at 104°FType II

Pressure Boundaries to Know Cold

45
→ low / medium boundary

170
→ medium / high boundary

355
→ high / very-high criterion

Important Distinction

HIGH SIDE
→ location in the refrigeration cycle

HIGH-PRESSURE APPLIANCE
→ regulatory refrigerant-pressure category

Do not confuse them.

3. Type II Leak Indicators and Leak Detection

Common Leak Clues

Possible leak indicators include:

  • Repeated refrigerant additions.
  • Oil residue around joints or components.
  • Low refrigerant charge.
  • Abnormal operating pressures or temperatures.
  • Evidence around valves, fittings, service ports, or seals.

An oil stain is:

A CLUE

not:

PROOF OF THE EXACT LEAK LOCATION

Important Leak Locations

Check items such as:

  • Service valves.
  • Schrader-type access fittings.
  • Flare and mechanical joints.
  • Brazed joints.
  • Coil connections.
  • Compressor fittings.
  • Receiver connections.
  • Relief-device connections.
  • Open-drive compressor shaft seals.

Leak-Location Methods

For refrigerant-containing systems, appropriate methods may include:

  • Electronic refrigerant leak detector.
  • Bubble solution.
  • Ultrasonic method where appropriate.
  • Manufacturer-approved methods.

For a recovered system safely pressurized with dry nitrogen:

BUBBLE SOLUTION
OR
ULTRASONIC METHOD

can help locate leakage.

A refrigerant-only electronic detector cannot detect pure nitrogen unless it is specifically designed to sense the test gas.

Standing Pressure Test

PRESSURE FALL
→ possible gas loss / leakage

but:

PRESSURE DECAY
≠
EXACT LEAK LOCATION

A separate locating method is required.

High Head Pressure Trap

High discharge/head pressure can result from:

  • Poor condenser heat rejection.
  • Noncondensables.
  • Overcharge.
  • Restricted discharge path.
  • Incorrect valve position.
  • High ambient conditions.

Therefore:

HIGH HEAD PRESSURE
≠
automatic proof of one specific problem

4. Current Section 608 Leak-Repair Rules

The current Section 608 leak-repair program applies to qualifying appliances with:

FULL CHARGE ≥50 lb

and an applicable:

CLASS I / CLASS II OZONE-DEPLETING REFRIGERANT
OR
ODS-CONTAINING BLEND

Current Trigger Rates

End UseCurrent Trigger Rate
Industrial process refrigeration30%
Commercial refrigeration20%
Comfort cooling10%
Other qualifying appliances10%

Memorize

IPR
→ 30%

COMMERCIAL
→ 20%

COMFORT / OTHER
→ 10%

Historical Study-Guide Values

Older material may show:

35%

and:

15%

These are historical, not the current Section 608 table.

Critical Type II Distinction

TYPE II
≠
LEAK-RATE CATEGORY

The leak trigger depends on the appliance’s end use, refrigerant, charge, and current regulatory applicability.

A Type II appliance is not automatically subject to § 82.157 merely because it is Type II.

Separate Current HFC Framework

Module 8 also distinguishes the separate current AIM Act HFC leak-repair framework.

Do not combine:

SECTION 608 ODS LEAK RULE

with:

AIM ACT HFC LEAK RULE

They are separate current federal programs with different applicability conditions.

5. Type II Recovery Preparation

Before recovery:

IDENTIFY APPLIANCE + REFRIGERANT
→ SELECT COMPATIBLE RECOVERY EQUIPMENT
→ INSPECT MACHINE
→ CLEAR PREVIOUS REFRIGERANT AS REQUIRED
→ IDENTIFY RECEIVER + FLOW PATH
→ PREPARE CYLINDER ON SCALE
→ IDENTIFY ACCESS POINTS
→ CONNECT
→ CHECK VALVES
→ SAFETY CHECK

Prepare the Recovery Cylinder

Confirm:

  • Correct refillable recovery cylinder.
  • Known contents.
  • Correct refrigerant stream.
  • Adequate available capacity.
  • Cylinder on a scale.
  • Stable and protected from excessive heat.

Identify Useful Access

Know:

  • High-side access.
  • Low-side access.
  • Liquid access.
  • Vapor access.
  • Receiver location.
  • Isolation valves.
  • Solenoids and check valves that may affect flow.

Exam trap: Not every receiver port necessarily contains liquid.

6. Type II Recovery Sequence

High-priority recovery logic:

RECOVER ACCESSIBLE BULK LIQUID FIRST
→ RECOVER REMAINING VAPOR
→ REACH REQUIRED ENDPOINT
→ ISOLATE + OBSERVE PRESSURE
→ RECOVER MORE IF PRESSURE REBOUNDS

Why Liquid First?

LIQUID RECOVERY
→ moves refrigerant mass faster
→ reduces total recovery time

when the appliance and recovery machine permit.

Vapor Completion

After accessible liquid is removed:

VAPOR RECOVERY
→ completes refrigerant removal

Vapor recovery also tends to reduce lubricant carryover compared with aggressively pulling liquid from oil-rich compressor regions.

Temperature Management

COOL RECOVERY CYLINDER SAFELY
→ lower cylinder pressure
→ lower recovery-machine back pressure

WARM APPLIANCE IN A CONTROLLED WAY
→ increase vapor pressure
→ help remaining refrigerant evaporate

Never use an open flame.

Do not heat the receiving recovery cylinder as a recovery-speed technique.

Pressure-Rebound Check

After reaching the apparent endpoint:

ISOLATE
→ OBSERVE PRESSURE

If pressure rises again, refrigerant may still be:

  • Evaporating from cold components.
  • Leaving compressor oil.
  • Trapped in isolated sections.

Then:

CONTINUE RECOVERY AS REQUIRED

Do not memorize one universal pressure-rise hold time; use the applicable equipment/service procedure.

Parallel Compressors

An isolated parallel compressor can still contain refrigerant.

ISOLATED COMPRESSOR
≠
EMPTY COMPRESSOR

Check and recover isolated sections as required.

7. System-Dependent Recovery Limit

Current Type II exam rule:

FULL CHARGE >15 lb
→ ordinary system-dependent recovery equipment prohibited

Exception:

PERMANENTLY ATTACHED PUMP-OUT UNIT

Important

The rule uses:

FULL CHARGE

not the amount currently remaining after a leak.

Exam Trap

15 lb
→ system-dependent recovery-equipment rule

200 lb
→ evacuation-table boundary

They are different rules.

8. Type II Evacuation Requirements

For appliances other than small appliances, MVACs, and MVAC-like appliances, use the current Table 1 requirement unless an applicable exception controls.

Current Type II Table 1

Type II AppliancePre-Nov. 15, 1993 Recovery EquipmentOn/After Nov. 15, 1993 Recovery Equipment
Very-high-pressure appliance0 in. Hg vacuum0 in. Hg vacuum
High-pressure, full charge <200 lb0 in. Hg vacuum0 in. Hg vacuum
High-pressure, full charge ≥200 lb4 in. Hg vacuum10 in. Hg vacuum
Medium-pressure, full charge <200 lb4 in. Hg vacuum10 in. Hg vacuum
Medium-pressure, full charge ≥200 lb4 in. Hg vacuum15 in. Hg vacuum

Post-1993 Memory Pattern

VERY HIGH
→ 0

HIGH <200 lb
→ 0

HIGH ≥200 lb
→ 10

MEDIUM <200 lb
→ 10

MEDIUM ≥200 lb
→ 15

Units:

in. Hg vacuum

Date Trap

November 15, 1993
→ recovery/recycling equipment date
→ NOT appliance manufacture date

9. Major Repair and Special Conditions

Major Maintenance, Service, or Repair

Removal of any of the following is major:

  • Compressor.
  • Condenser.
  • Evaporator.
  • Auxiliary heat-exchange coil.

Also major:

OPENING >4 in² OF FLOW AREA
+
OPEN >15 min

Major-Repair Decision

REMOVE compressor / condenser / evaporator /
auxiliary heat-exchange coil?
→ YES → MAJOR

Otherwise:

OPENING >4 in²
AND
>15 min?
→ YES → MAJOR

Otherwise:

POTENTIALLY NON-MAJOR
→ CHECK CURRENT SERVICE-PRACTICE CONDITIONS

Normal Major Repair

MAJOR REPAIR
→ applicable TABLE 1 endpoint

Filter-Drier Trap

A filter-drier is not one of the four named major components.

FILTER-DRIER REPLACEMENT
≠
automatically major

The opening size/time and applicable service conditions still matter.

Qualifying Non-Major Type II Opening

When all current conditions are satisfied:

NO HIGHER THAN 0 psig

may be used before opening under the limited non-major provision.

Leaking System Prevents Table 1

Where possible:

ISOLATE LEAKING + NON-LEAKING PORTIONS

Then:

NON-LEAKING PORTION TO BE OPENED
→ TABLE 1

LEAKING PORTION TO BE OPENED
→ LOWEST ATTAINABLE PRESSURE
→ NOT ABOVE 0 psig

Oil Change

Current special oil-change provision:

NO HIGHER THAN 5 psig

Burnout

Compressor burnout can spread:

  • Acid.
  • Carbon.
  • Moisture.
  • Contaminated oil.
  • Particulate contamination.

Burnout cleanup can include:

CONTAMINATION CONTROL
+
FILTER-DRIER SERVICE
+
PROPER EVACUATION
+
FOLLOW-UP EVALUATION

Moisture Indicator

READ MANUFACTURER'S COLOR LEGEND

Do not assume one universal moisture-indicator color.

10. Type II Safety

Reciprocating Compressor

DISCHARGE SERVICE VALVE CLOSED
→ DO NOT ENERGIZE

A reciprocating compressor is a positive-displacement machine. A closed discharge path can create a rapid, dangerous pressure rise.

Hermetic Compressor Under Vacuum

DEEP VACUUM
→ DO NOT ENERGIZE HERMETIC COMPRESSOR

Use an external vacuum pump for evacuation.

Deep-vacuum operation can create risk of internal electrical arcing and motor/terminal damage.

Crankcase Heater

COLD OFF-CYCLE COMPRESSOR
→ refrigerant migration into oil
→ oil dilution
→ startup foaming
→ lubrication risk

A crankcase heater can reduce off-cycle refrigerant migration when the system design requires one.

High Discharge Pressure

Possible causes:

  • Poor condenser heat rejection.
  • Noncondensables.
  • Overcharge.
  • Restricted discharge path.
  • Incorrect valve positions.
  • High ambient conditions.

Correct response:

DIAGNOSE + CORRECT

not:

BYPASS SAFETY CONTROL

Pressure Relief

RELIEF DEVICE
→ emergency overpressure protection

Do not defeat, isolate improperly, or bypass required protection.

Machinery Room

For EPA exam preparation:

REFRIGERANT RELEASE
→ DETECTION
→ ALARM / VENTILATION SAFETY

Actual field requirements depend on the currently adopted safety standard and local code.

Very-High-Pressure Appliances

Verify:

  • Recovery-machine pressure rating.
  • Hose rating.
  • Gauge/manifold rating.
  • Cylinder suitability.
  • Refrigerant compatibility.
  • Fitting/tool rating.
PHYSICAL CONNECTION
≠
ADEQUATE PRESSURE RATING

11. Type II Numbers to Know Cold

Number / DateMeaning
45 psia @ 104°FLow / medium pressure boundary
170 psia @ 104°FMedium / high pressure boundary
355 psia @ 104°FHigh / very-high pressure criterion
>15 lb full chargeOrdinary system-dependent recovery equipment prohibited unless permanent pump-out
November 15, 1993Recovery-equipment date boundary
200 lbCharge boundary changing several Type II evacuation rows
0 / 4 / 10 / 15 in. Hg vacuumType II Table 1 values
50 lb or moreCurrent Section 608 ODS leak-repair applicability threshold
30% / 20% / 10%Current Section 608 leak-rate triggers
>4 in² + >15 minNumerical major-repair condition
0 psigCurrent qualifying non-major / leaking-section pressure concept
5 psigCurrent oil-change special provision

12. Highest-Priority Type II Exam Traps

Trap 1

Type II = high pressure only

Wrong. Type II also includes medium and very-high pressure.

Trap 2

5 lb or less
→ Type I

Wrong. The complete small-appliance definition controls.

Trap 3

Every chiller
→ Type III

Wrong. Pressure classification controls.

Trap 4

15 lb
→ evacuation table boundary

Wrong. 15 lb is the system-dependent recovery-equipment limit.

Trap 5

50 lb
→ evacuation table boundary

Wrong. 50 lb is the current Section 608 ODS leak-repair applicability threshold.

Trap 6

200 lb
→ leak-repair threshold

Wrong. 200 lb changes certain Type II Table 1 rows.

Trap 7

Historical 35% / 15%
→ current leak rates

Wrong.

Current Section 608:

30% / 20% / 10%

Trap 8

First low pressure reading
→ recovery complete

Wrong. Check pressure rebound.

Trap 9

Pressure rebound
→ always an external leak

Wrong. Remaining refrigerant may be evaporating from oil or cold components.

Trap 10

Filter-drier replacement
→ automatically major

Wrong.

Trap 11

Hermetic compressor under deep vacuum
→ start it to help evacuation

Wrong.

Trap 12

High-pressure control trips
→ bypass control

Wrong. Diagnose and correct the cause.

13. Type II Final Memory Map

TYPE II
→ MEDIUM + HIGH + VERY HIGH PRESSURE

45 / 170 / 355 psia @ 104°F
→ pressure-category boundaries

LEAK DETECTION
→ clues locate AREA
→ detector / bubbles / ultrasonic locate LEAK

SECTION 608 ODS LEAK REPAIR
→ ≥50 lb
→ 30% / 20% / 10%

RECOVERY
→ LIQUID FIRST WHERE PRACTICAL
→ VAPOR FINISH
→ PRESSURE-REBOUND CHECK

>15 lb FULL CHARGE
→ no ordinary system-dependent recovery
→ unless permanent pump-out

POST-1993 TYPE II TABLE
→ 0 / 10 / 15 in. Hg vacuum
→ depends on pressure category + 200-lb boundary

MAJOR
→ compressor / condenser / evaporator /
auxiliary heat exchanger
OR
>4 in² + >15 min

QUALIFYING NON-MAJOR
→ ≤0 psig

OIL CHANGE
→ ≤5 psig

RECIPROCATING COMPRESSOR
+ CLOSED DISCHARGE
→ DO NOT ENERGIZE

HERMETIC COMPRESSOR
+ DEEP VACUUM
→ DO NOT ENERGIZE

CRANKCASE HEATER
→ reduces refrigerant migration into oil

HIGH HEAD PRESSURE
→ diagnose condenser / noncondensables /
overcharge / restriction
→ DO NOT bypass safety

References

Project Source Sections