Year 3 Exam Study Guide — master what the exam actually tests, concept by concept.
Mechanical trades involve high pressures, extreme temperatures, rotating machinery, and chemical hazards. The exam tests whether you can identify risks before they become incidents — covering everything from confined space entry to pressure testing safety.
Accumulator isolation requires depressurization to 0 psi. Residual 510 psi is a hazard during disassembly. Safety regulations exist because the consequences of ignoring them are severe — injury, death, or legal liability. Know these requirements the way you know your own name.
Mechanical work is governed by a stack of codes: plumbing codes, gas codes, pressure vessel codes, ASHRAE standards, and provincial regulations. Exam questions test your ability to apply these standards to real scenarios — knowing when a rule applies, what the limit is, and why it exists.
High pilot drain pressure indicates spool/bore wear or blockage. Reduces servo response and control stability. Troubleshooting is a systematic process: identify symptoms, narrow down causes logically, and verify your diagnosis before replacing parts. This logical approach is what examiners want to see.
ISO 4406 code: particles ≥4µm count / ≥6µm count / ≥14µm count per mL. 18/16/13 is industrial-grade cleanliness. Understanding and applying code requirements correctly ensures your installations pass inspection and meet legal obligations in your jurisdiction.
Cold-start high viscosity causes pump cavitation and reduced flow until system warms. Anti-cavitation breather or immersion heater may be needed. Troubleshooting is a systematic process: identify symptoms, narrow down causes logically, and verify your diagnosis before replacing parts. This logical approach is what examiners want to see.
Regulator sets pressure at its outlet (downside). If 90 psi is needed, setting is correct. Verify against circuit requirement. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Spring-centered valve: solenoid moves spool, spring returns it to neutral when de-energized. Standard on simple circuits. Understanding and applying code requirements correctly ensures your installations pass inspection and meet legal obligations in your jurisdiction.
Total pull = friction + elevation lift. Friction ≈ µ × load; elevation = load × g × height/distance. Sum determines motor size. Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
Total pull = friction + elevation lift
Coupling rated torque should be 1.5-2× application maximum. At 2500 in-lbs applied vs 3000 rated, minimal margin exists. When solving calculation questions, always identify your known variables first, select the correct formula, and double-check your units before calculating.
Mechanical systems live and die by numbers — the wrong pipe size creates pressure loss, the wrong refrigerant charge affects efficiency, the wrong gas orifice is a hazard. These calculations aren't abstract math; they're engineering decisions made in the field every day.
3× running speed indicates misalignment—creates repetitive 3× impulses per shaft revolution. When solving calculation questions, always identify your known variables first, select the correct formula, and double-check your units before calculating.
BPFO requires bearing dimensions. At 30 Hz shaft speed, typical BPFO ≈ 300-500 Hz; 2.5 kHz is likely cage/other component. Troubleshooting is a systematic process: identify symptoms, narrow down causes logically, and verify your diagnosis before replacing parts. This logical approach is what examiners want to see.
Ultrasonic frequency signature indicates early-stage bearing degradation before conventional vibration shows failure. Troubleshooting is a systematic process: identify symptoms, narrow down causes logically, and verify your diagnosis before replacing parts. This logical approach is what examiners want to see.
Pump-motor speed ratio = displacement ratio. Flow distributed over 2× displacement = half speed, 2× torque. Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
motor speed ratio = displacement ratio
Pilot ratio means main spool area is 10× pilot piston area. 10 psi pilot = 100 psi output (unless load-check valves reduce it). Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
psi pilot = 100 psi output (unless load-check valves reduce it)
Extend: F = P × π(2)² ≈ 628 lbf. Retract: F = P × [π(2)² - π(1.5)²] ≈ 449 lbf (rod area subtracts). Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
F = P × π(2)² ≈ 628 lbf
Speed = Q/A. 5 gpm = 0.0111 ft³/sec. Area = π(1.5)²/144 = 0.0491 ft². Speed ≈ 0.0111/0.0491 ≈ 0.23 ft/sec ≈ 2.7 in/sec. (Answer varies with calculation method; typical result ~0.8 ft/sec or 10 in/sec.) Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
Speed = Q/A
Output torque ≈ Input torque × gear ratio (minus 3% loss). Input = 63,025 × HP / rpm = 63,025 × 20 / 1800 ≈ 700 ft-lbs. Output ≈ 700 × 4 ≈ 2800 ft-lbs. Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
Input = 63,025 × HP / rpm = 63,025 × 20 / 1800 ≈ 700 ft-lbs
Backlash (linear) = backlash (angular) × radius = (10/3437 rad) × 5 in ≈ 0.0145 inches. Memorize this formula and practise substituting values — exam questions often give you three variables and ask you to solve for the fourth.
Backlash (linear) = backlash (angular) × radius = (10/3437 rad) × 5 in
Planetary formula: (sun + ring) / 2 = planet speed. With ring locked: input sun speed × sun teeth / ring teeth = 1000 × 40/100 = 400 rpm carrier. (Formula varies; check standard.) Understanding and applying code requirements correctly ensures your installations pass inspection and meet legal obligations in your jurisdiction.
ring teeth = 1000 × 40/100 = 400 rpm carrier
Bucket elevator power ≈ (load + belt) × (friction + height factor). 500 tph at 50 feet ≈ 50-70 HP depending on efficiency. When solving calculation questions, always identify your known variables first, select the correct formula, and double-check your units before calculating.
30°C temperature rise at bearing with light load suggests friction. Investigate bearing condition and lubrication. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Pipes, valves, fittings, and mechanical components have ratings, classifications, and compatibility requirements. Using the wrong material can fail an inspection, void a warranty, or create a dangerous condition. This section covers proper material selection and equipment knowledge.
Localized hot spot at bearing (30°C above normal surface) indicates friction from lack of lubrication or misalignment. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Iron content tracks ferrous wear. 500 ppm is severe; investigate immediate bearing/tooth condition. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Reverse dial method: over-align cold by expected growth amount so hot alignment is perfect during operation. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Laser tracker (reflector-based) achieves sub-0.001" accuracy, well within mechanical coupling tolerances. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Slow response indicates: solenoid armature friction, electrical weakness, or fluid viscosity/contamination. Troubleshooting is a systematic process: identify symptoms, narrow down causes logically, and verify your diagnosis before replacing parts. This logical approach is what examiners want to see.
Screw conveyor discharge pressure depends on material properties and fill factor. Sand ≈ 0.5-1.5 psi. Material selection directly affects performance, code compliance, and longevity. Using the wrong type can fail an inspection or create a hazard down the line.
Water >1000 ppm promotes corrosion and rust in gear teeth. Drainage/replacement required at 2000 ppm. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Procedure matters in mechanical work. The order of operations, the proper testing sequence, the way you commission a system — doing it right the first time means no leaks, no callbacks, and no danger. This section covers procedures as they appear on the exam and as they're done on the job.
Soft foot shims bring machine feet into coplanar contact, eliminating frame bending stress and vibration amplification. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Coupling tolerances specified by manufacturer. Combining axial and angular offsets increases stress; verify against rated limits. On the job, a solid grasp of this concept means faster decisions, fewer errors, and work that passes inspection the first time.
Frame bending from soft foot misaligns bearing, creating radial load and excessive friction. Shimming fixes root cause. Troubleshooting is a systematic process: identify symptoms, narrow down causes logically, and verify your diagnosis before replacing parts. This logical approach is what examiners want to see.
All 30 exam concepts from this guide — test your recall before you sit the exam.