Gasfitter - Class A - Exam Information

Self-Assessment
Exam Breakdown
Types of Exam Questions
Math Formulas
Acronyms

Self-Assessment

This tool can be used to reflect on your own experience and knowledge in the trade compared with what is on the exam.

Exam Breakdown

Each Red Seal exam's questions are developed to assess the activities laid out in the Red Seal Occupational Standard. This trade's Red Seal exam has 100 questions^{Footnote *}, which are distributed as follows:

Major Work Activity A - Performs common occupational skills - 5 questions

Task A-1 Performs safety-related functions

1 question

Task A-2 Uses tools and equipment

2 questions

Task A-3 Organizes work

2 questions

Task A-4 Uses communication and mentoring techniques

0 questions

Major Work Activity B – Installs fuel piping and tubing systems - 9 questions

Task B-5 Selects and installs piping for fuel systems

5 questions

Task B-6 Selects and installs tubing for fuel systems

4 questions

Major Work Activity C – Installs venting and air supply systems - 13 questions

Task C-7 Selects and installs venting systems

5 questions

Task C-8 Selects and installs air supply systems

5 questions

Task C-9 Selects and installs draft control systems

3 questions

Major Work Activity D – Installs controls and electrical systems - 19 questions

Task D-10 Selects and installs combustion control systems

4 questions

Task D-11 Selects and installs flame safeguard systems

5 questions

Task D-12 Selects and installs operating control systems

4 questions

Task D-13 Selects and installs electrical systems

4 questions

Task D-14 Selects and installs automation and instrumentation control systems

2 questions

Major Work Activity E - Installs and converts fuel systems, appliances and ancillary equipment - 13 questions

Task E-15 Selects, installs and converts fuel systems, appliances and ancillary equipment

6 questions

Task E-16 Selects and installs propane and natural gas storage, handling and dispensing systems

5 questions

Task E-17 Selects and installs other fuel storage, handling and dispensing systems

2 questions

Major Work Activity F - Tests and commissions fuel systems, appliances and ancillary equipment - 23 questions

Task F-18 Tests fuel delivery systems

9 questions

Task F-19 Commissions fuel systems, appliances and ancillary equipment

14 questions

Major Work Activity G - Services fuel systems, appliances and ancillary equipment - 18 questions

Task G-20 Maintains fuel systems, appliances and ancillary equipment

7 questions

Task G-21 Repairs fuel systems, appliances and ancillary equipment

8 questions

Task G-22 Decommissions fuel systems, appliances and ancillary equipment

3 questions

Types of Exam Questions

All Red Seal exam questions are written in multiple-choice format. A multiple-choice question consists of question followed by four possible responses (A, B, C, D). Every question has exactly one correct answer and three incorrect options. They are not misleading or trick questions, but the incorrect options are not always obvious.

There are three types of questions that you will see on Red Seal Exams:

Knowledge and Recall
Procedural and Application
Critical Thinking

Knowledge and Recall

This type of question tests your ability to recall and understand definitions, facts and principles.

For this trade, between 15 and 25% of questions that are this type.

Example of a Knowledge and Recall Question:

What is called the time it takes for a primary or programming control to shut off the fuel supply in the event of a loss of flame signal?

Flame failure response time.
Pilot relay shut-down.
Turndown time.
Flame lock-out.

Answer: A

Procedural and Application

This type of question tests your ability to apply your knowledge of procedures to a situation.

For this trade, between 60 and 70% of questions are this type.

Example of a Procedural and Application Question:

The positive air pressure switch on a DFMAH unit is being verified during an inspection. How is the pressure measurement obtained?

By placing dual port manometer in parallel with pressure switch.
By placing anemometer in series with pressure switch.
By placing dual port manometer in series with pressure switch.
By placing anemometer in parallel with pressure switch.

Answer: A

Critical Thinking

This type of question tests your ability to interpret data, solve problems and arrive at valid conclusions.

For this trade, between 10 and 20% of questions are this type.

Example of a Critical Thinking Question:

What is the minimum ventilation air opening for a boiler room containing a power burner with a firing rate of 1 000 000 Btuh?

3.34 in²
7.15 in²
10.00 in²
14.20 in²

Answer: C

Try more sample questions for this trade and check out the Exam Preparation Guide. It will give you practical insights on what goes into Red Seal exams, and how you can best prepare yourself to do well.

Math Formulas

Formulas [PDF, 187 KB]

The following formulas used in this trade may be needed to answer some questions on its Red Seal exam. They will also be provided with the exam sitting.

Formulas

Measurement unit abbreviations

°C: degree Celsius
°F: degree Fahrenheit
°K: degree Kelvin
A: ampere
BHP: boiler horsepower
BTU: British thermal unit
Btuh: British thermal units per hour
CFH: cubic feet per hour
CFM: cubic feet per minute
ft.: foot
ft²: square foot
ft³: cubic foot
gal.: imperial gallon
gpm: imperial gallons per minute
hr: hour
in.: inch
in²: square inch
in³: cubic inch
kg: kilogram
kPa: kilopascal
kPaG: kilopascal gauge
kW: kilowatt
L: litre
lb.: pound
lbf: pound - force
m: metre
m²: square metre
m³: cubic metre
min: minute
mm: millimetre
psi: pounds per square inch
psia: pounds per square inch absolute
psig: pounds per square inch gauge
s: second
SCFM: standard cubic feet per minute
SPR: seconds per rotation
t: ton (ice melted over a 24-hour period)
USG: American gallon
USGPM: American gallons per minute
V: volt
VA: volt-ampere
W: watt

Values

∆T: temperature difference
B: base
BarG: bar gauge
C: specific heat of fluid
CO₂: carbon dioxide
D: distance
FCS: fully closed signal
FOS: fully open signal
H: height
HV: heating value
I: current (in amperes)
IS: input signal
L: length
M: mass of fluid per hour
P: pressure
P_base: base/atmospheric pressure
P_test: test pressure
PF: pressure factor
r: radius
R: resistance (in ohms)
SF: safety factor
stoich: stoichiometric
T: temperature
T_amb: ambient temperature
W: width

Constants

π: 3.1416
1 ft³ of water: 6.228 gal.
1 USG: 8.33 lb.
45° offset: 1.414
12 000 BTU (cooling capacity): 1 t
Air- fuel ratio: 14.7
Base/atmospheric pressure: 14.73 psig/psia
Boiler horsepower (BHP): 33 500
BTU per 1 000 W (single phase): 3.414
BTU per 1 000 W (three phase): 1.73
Heat content - natural gas: 1 000 BTU/ft³
Heat content - propane: 2 500 BTU/ft³
Pressure head conversion unit: 0.433 psi/ft.
Specific heat of air: 1.08
Standard for air at sea level: 4.5

Conversion factors

Conversion factors
To convert	To	Multiply by
°C	°F	1.8 and add 32
°C	°K	1 and add 273
decimal	second	60
ft²	in²	144
ft³	USG	7.48
kg	lb.	2.205
kPa	lbf/ft²	20.88
kPa	lbf/in² (psi)	0.1450
kPaG	lbf/in² gauge (psig)	0.1450
L	USG	0.2200
L/min	USGPM	0.2641
L/s	gpm	13.20
m	ft.	3.281
m²	ft²	10.76
m³	ft³	35.31
mm	in.	0.03937

General formulas

General formulas
Descriptions	Full	Abbreviated
% of CO₂	$\frac{stoichiometric {CO}_{2}}{1 + (% of excess air \div 100)}$	$\frac{stoich {CO}_{2}}{1 + (\frac{% excess air}{100})}$
Actuator position (%)	$\frac{input signal - fully closed signal}{fully open signal - fully closed signal}$	$\frac{IS - FCS}{FOS - FCS}$
Btuh	mass of fluid per hour × specific heat of fluid × temperature difference	$M \times C \times Δ T$
CFH	$(\frac{appliance output in Btuh}{appliance efficiency %}) \div heating value$	$\frac{output}{efficiency} \div HV$
CFH	$\frac{appliance output in Btuh}{heating value}$	$\frac{output}{HV}$
CFH	(dial size ÷ seconds per rotation) × seconds in 1 hour × pressure factor	$\frac{dial}{SPR} \times 3 600 \times PF$
CFH	$\frac{seconds in 1 hour \times dial size}{seconds per rotation}$	$\frac{3 600 \times dial}{SPR}$
CFM	$\frac{(British thermal units per hour \times efficiency)}{(specific heat of air \times temperature difference)}$	$\frac{Btuh \times E}{1.08 \times Δ T}$
CO₂ volume (combustion)	appliance output in Btuh × cubic feet of CO₂ per cubic foot of gas ÷ heating value	$output \times {ft}^{3} of {CO}_{2} / {ft}^{3} of gas \div HV$
Fuse rating	amperes × safety factor	$A \times SF$
Gauge pressure reading	$(\frac{(pressure + air-fuel ratio) \times (temperature difference + temperature)}{ambient temperature + temperature}) - air-fuel ratio$	$(\frac{(p + 14.7) \times (△ T + T)}{T_{amb} + T}) - 14.7$
Input (Btuh)	$\frac{appliance output in Btuh}{appliance efficiency %}$	$\frac{output}{efficiency}$
Input (Btuh)	(base pressure + dial size) × cubic feet per hour ÷ base pressure × heating value	$(\frac{[P_{base} + dial] \times CFH}{P_{base}}) \times HV$
Input (Btuh)	cubic feet per hour × heating value	$CFH \times HV$
Input (Btuh)	$(\frac{seconds in 1 hour \times bar gauge}{seconds per rotation}) \times (\frac{base pressure + bar gauge}{base pressure}) \times heating value$	$(\frac{3 600 \times BarG}{SPR}) \times (\frac{P_{base} + BarG}{P_{base}}) \times HV$
Net stack temperature	downstream flue temperature − ambient temperature	$downstream flue T - T_{amb}$
Output (Btuh)	temperature difference × 1 USG × minutes in 1 hour × American gallons per minute	$Δ T \times 8.33 \times 60 \times USGPM$
Output (Btuh)	total number of boiler horsepower × number of boilers	$# BHP \times 33 500 \times # boilers$
Power	volt × ampere	$V \times A$
Pressure factor	(base pressure + bar gauge) ÷ base pressure	$\frac{P_{base} + BarG}{P_{base}}$
Pressure test	$(\frac{[combustion rate \times number of cylinders] + (136.354 \times air-fuel ratio)}{[test pressure \times number of cylinders] + 136.354}) - air-fuel ratio$	$(\frac{[comb. rate \times # cyl.] + (136.354 \times 14.7)}{[P_{test} \times # cyl.] + 136.354}) - 14.7$
Purge time	cubic feet per minute × number of air changes ÷ exhaust fan capacity measured in standard cubic feet per minute	$\frac{CFM \times # air changes}{SCFM}$
Seconds per rotation	$\frac{cubic feet per hour}{(seconds in 1 hour \times pressure factor)} \times dial size$	$\frac{CFH}{(3 600 \times PF)} \times dial$
Travel	offset distance × 45° offset constant	$offset D \times 1.414$
Volt ‑ ampere	current × voltage	$I \times E$
Voltage	current × resistance	$I \times R$

Area formulas

Description	Full	Abbreviated
Circle	π × radius squared	$π r^{2}$
Rectangle	length × width	$L \times W$
Sphere	4 × π × radius squared	$4 π r^{2}$
Triangle	$\frac{base \times height}{2}$	$\frac{B \times H}{2}$

Volume formulas

Volume formulas
Description	Full	Abbreviated
Cuboid	length × width × height	$L \times W \times H$
Cylinder	π × radius squared × height	$π r^{2} H$
Sphere	$\frac{4 \times π \times radius cubed}{3}$	$\frac{4 π r^{3}}{3}$

Acronyms

Acronyms [PDF, 98 KB]

The following acronyms used in this trade may be on its Red Seal exam. They will also be provided with the exam sitting.

°C: degree Celsius
°F: degree Fahrenheit
Δ: delta (difference)
ΔT: temperature difference
Ω: ohm
A: ampere
ABS: acrylonitrile butadiene styrene
AC: alternating current
ACR: air conditioning and refrigeration
ACV: alternating current voltage
AHJ: authority having jurisdiction
ANSI: American National Standards Institute
ASHRAE: American Society of Heating, Refrigerating, and Air Conditioning Engineers
ASME: American Society of Mechanical Engineers
ASTM: American Society for Testing and Materials
AUX: auxiliary
BAC: building automation and control
BHP: boiler horsepower
BLR: boiler
BTU: British thermal unit
Btuh: British thermal units per hour
BVSS: blocked vent safety switch
CO: carbon monoxide
CO₂: carbon dioxide
CPVC: chlorinated polyvinyl chloride
CSA: Canadian Standards Association
CSST: corrugated stainless steel tubing
dB: decibel
DC: direct current
DFMAH: direct-fired make-up air heater
DSI: direct spark igniter
FARC: fuel/air ratio control
ft.: foot
ft²: square foot
ft³: cubic foot
ft³/hr: cubic feet per hour
gal.: imperial gallon
HGPS: high gas pressure switch
hp: horsepower
hr: hour
HSI: hot surface igniter
HVAC: heating, ventilation, and air conditioning
Hz: hertz
in.: inch
in. w.c.: inches per water column
in²: square inch
in³: cubic inch
IR: infrared
kΩ: kiloohm
kPa: kilopascal
kVA: kilovolt-ampere
kW: kilowatt
L: litre
L/HGPS: low/high gas pressure switch
lbf: pound-force
LED: light-emitting diode
LGPS: low gas pressure switch
LMR: longest measured run
LOTO: lock-out/tag-out
LP: liquified petroleum
LWCO: low water cut-off
m: metre
mA: milliampere
MBH: thousands of BTU per hour
min: minute
mm: millimetre
MMBH: millions of BTU per hour
MTFI: main trial for ignition
MUA: make-up air
mV: millivolt
NC: normally closed
NGV: natural gas vehicle
NO: normally open
NOx: nitrogen oxides
NPS: nominal pipe size
O₂: oxygen
OHS: Occupational Health and Safety
OPPD: overpressure protection device
PB: proportional band
PID: proportional integral derivative
PLC: programmable logic controller
POC: proof of closure
PPE: personal protective equipment
ppm: parts per million
PRV: pressure regulating valve
psi: pounds per square inch
psia: pounds per square inch absolute
psig: pounds per square inch gauge
PTFI: pilot trial for the ignition
PVC: polyvinyl chloride
rpm: revolutions per minute
RTD: resistance temperature detector
RTU: remote terminal unit
s: second
SCFM: standard cubic feet per minute
SCR: silicon-controlled rectifier
Sp. gr.: specific gravity
SS: stainless steel
SSOV: safety shut-off valve
TFI: trial for ignition
UPS: uninterrupted power supply
USG: American gallon
USWG: American water gallon
UV: ultraviolet
V: volt
V-mA: volt-milliampere
VAC: volt alternating current
VDC: volt direct current
VFD: variable frequency drive
w.c.: water column

For more information about exam preparation materials contact your provincial/territorial apprenticeship office.

Gasfitter - Class A - Exam Information

Table of Contents

Knowledge and Recall

Procedural and Application

Critical Thinking

Formulas

Measurement unit abbreviations

Values

Constants

Conversion factors

General formulas

Area formulas

Volume formulas