DC3

Liquid vaporized by absorbing heat in a refrigeration system?

Evaporator

Valve type best suited for throttling service?

Globe valve

Acceptable range for residual sodium sulfite in boiler water?

30 - 70 ppm

BTU content of one gallon of #4 fuel oil?

146,000 BTU

Regeneration agent used in a Zeolite water softener?

Brine (salt solution)

4 steps of the Zeolite water softener rejuvenation process?

Backwash, Brine, Rinse, Service

Where high-temperature vapor is found in a refrigeration system?

Discharge of the compressor / inlet of condenser

Wire connecting all system components to a physical ground or water pipe?

Grounding Electrode Conductor

How to calculate Refrigerant Superheat?

Subtract saturated suction temperature (from P/T chart) from actual suction line temperature

How to calculate Refrigerant Sub-cooling?

Subtract actual liquid line temperature from saturated liquid temperature (from P/T chart)

Location of quick-opening valve when paired with a screw-type blowdown valve?

Closest to the boiler (followed by the screw-type valve)

Order of operation for boiler blowdown (quick-opening & screw-type valves)?

Open quick-opening FIRST; close quick-opening LAST

ASME definition of a slow-opening valve?

Requires at least 5 full 360-degree turns to fully open or close

How often water level and LWCO should be checked during operation?

Once per shift

Primary purpose of oil in a refrigeration system?

Lubrication of compressor moving parts

Chemical compounds causing PERMANENT hardness in boiler water?

Calcium Sulfate and Magnesium Silicate

Chemicals used to combat dissolved oxygen and corrosion?

Sodium Sulfite and Hydrazine

What to add to boiler water with a pH of 5 (acidic) to neutralize it?

Bases (Alkaline treatment)

Mechanical device used to remove scale from FIRE tubes?

Tube Rattler or Vibrator

Mechanical device used to remove scale from WATER tubes?

Tube Turbine

The Three "T's" of complete combustion?

Time, Temperature, Turbulence

Purpose of a siphon installed on a steam pressure gauge?

Creates a water seal to protect the gauge/controls from live steam

Total Force (TF) formula on a safety valve disc?

TF = Pressure (P) × Area (A)

Where to locate an expansion tank on a closed-loop system?

On the suction side of the pump

Purpose of a crankcase heater on a reciprocating chiller?

Prevents refrigerant migration and oil dilution

Which pump type can be safely started with its discharge valve CLOSED?

Centrifugal pump

Definition of pump slip?

The difference between theoretical capacity and actual delivered capacity

Primary cause of high temperature (steam venting) in a condensate tank?

Steam traps stuck OPEN

Formula to convert Celsius to Fahrenheit?

F = (C × 1.8) + 32

What is the equivalent Boiler Horsepower (BHP) for generating 34.5 lbs of steam/hr?

1 Boiler Horsepower (BHP)

Last line of defense against boiler overheating from low water?

Low Water Fuel Cut-Off (LWCO)

Standard hydrostatic test pressure for a boiler?

1.5 times the Maximum Allowable Working Pressure (MAWP)

Heat that causes a change in temperature but no change in state?

Sensible heat

Heat that causes a change in state but no change in temperature?

Latent heat

Draft system where a fan is located in the breeching or stack to PULL air through the furnace?

Induced draft

Draft system where a fan PUSHES air into the furnace?

Forced draft

Condition where boiler water carries over into the steam lines due to high surface tension from impurities?

Foaming

Primary purpose of the boiler purge cycle prior to ignition?

Remove unburned combustible gases from the furnace to prevent explosions

Valves on a water column used to manually verify the water level if the gauge glass breaks?

Try cocks

How to calculate Absolute Pressure (PSIA)?

Gauge Pressure (PSIG) + Atmospheric Pressure (14.7 psi)

Device used to measure the draft in a boiler furnace?

Manometer (measured in inches of water column)

What is the absolute pressure of a boiler operating at 100 PSIG?

114.7 PSIA

Formula for the Area of a Circle?

Area = D² × 0.7854

Formula for the Circumference of a Circle?

Circumference = D × 3.14

Formula for the Volume of a Cylinder?

Volume = Area of a circle × Height (or Length)

How many cubic inches are in one gallon of water?

231 cubic inches

How to calculate tank capacity in gallons from a volume in cubic inches?

Gallons = Total cubic inches / 231

Formula for the Area of a Triangle?

Area = 1/2 × Base × Height

Formula for Total Force (TF) acting on a safety valve disc?

TF = Pressure (P) × Area (A)

Formula to find the popping Pressure (P) of a safety valve if Force and Area are known?

P = Total Force (TF) / Area (A)

Formula to calculate Boiler Horsepower (BHP) using the factor of evaporation?

BHP = (lbs of steam per hour × Factor of Evaporation) / 34.5

How many pounds of water evaporated per hour equals 1 Boiler Horsepower?

34.5 lbs/hr (from and at 212°F)

Formula for Pump Motor Horsepower?

HP = (GPM × 8.33 × Height in feet) / (33,000 × Pump Efficiency)

What constant is used for the weight of one gallon of water in pump horsepower equations?

8.33 lbs

How to convert feet of head (water column) to pressure in PSI?

PSI = Head in Feet / 2.31

Formula to calculate the thermal expansion of a steel pipe?

Expansion in inches = (T1 - T2) × Length in inches × 0.0000065

Formula for the capacity (GPM) of a Duplex Reciprocating Pump?

GPM = (L × A × N × E) / 231

Formula to calculate maximum water pressure (Pw) of a steam-driven duplex pump?

Pw = (Steam Pressure × Area of Steam piston) / Area of Water piston

Formula to convert Fahrenheit to Rankine (Absolute Temperature)?

R = F + 460

Formula to convert Celsius to Kelvin (Absolute Temperature)?

K = C + 273

Formula to determine total water hardness (TH) from Calcium (C) and Magnesium (M)?

TH = (C × 2.5) + (M × 4.1)

Formula for calculating water flow rate (GPM) through a pipe based on velocity?

GPM = (Velocity × D²) / 0.4085

Formula to convert Fahrenheit to Celsius?

C = (F - 32) / 1.8

What is the standard density constant for steam used in these pipe sizing calculations?

0.037 lbs/ft³

Formula for Pump Horsepower when Specific Gravity is a known factor?

HP = (GPM × 8.33 × Height × Specific Gravity) / (33,000 × Efficiency)

Formula for calculating the required volume of a closed expansion tank (V1)?

V1 = (((0.00041 × t) - 0.0466) × Vs) / ((Pa/Pf) - (Pa/Po))

Formula for calculating pipe diameter (D) using steam capacity and density?

D = 12 × (C / d / h / 0.7854)

Formula for Ohm's Law?

Voltage (V) = Current (I) × Resistance (R)

Formula for Electrical Power (Watts)?

Watts (W) = Voltage (V) × Current (I)

In a SERIES circuit, what remains constant across all components?

Current (Amps)

In a PARALLEL circuit, what remains constant across all components?

Voltage (Volts)

Device used to step up or step down alternating current (AC) voltage?

Transformer

What is the unit of measure for electrical resistance?

Ohms

What is the unit of measure for electrical current?

Amperes (Amps)

What is the unit of measure for electromotive force (electrical pressure)?

Volts

What type of power is standard for heavy commercial motors, pumps, and chillers?

3-Phase AC Power

What does an inverter do?

Converts DC power to AC power

What does a rectifier do?

Converts AC power to DC power

What is the primary purpose of an electrical relay or contactor?

Allows a low-voltage control circuit to switch a high-voltage load circuit

What is the function of a thermal overload relay on a motor starter?

Protects the motor from overheating due to excessive current draw

A circuit defect with almost zero resistance, allowing massive current flow and tripping breakers?

Short circuit

What is the primary purpose of the equipment grounding conductor?

Provides a safe, low-resistance path to ground for fault current to prevent electric shock

Device used to measure the electrical current (Amps) flowing through a wire without disconnecting it?

Clamp-on Ammeter