1️⃣ What is the role of a mechanical engineer in an industrial plant?
Answer:
A mechanical engineer ensures safe, reliable, and efficient operation of mechanical systems such as piping, pumps, compressors, vessels, and rotating equipment. Responsibilities include installation supervision, maintenance planning, shutdown execution, troubleshooting failures, coordinating with other disciplines, ensuring safety compliance, and maintaining documentation as per standards and drawings.
2️⃣ What checks are required before starting mechanical construction work?
Answer:
Before starting work, engineers must verify approved drawings, work permits, material availability, manpower, tools, lifting plans, and safety arrangements. Site conditions, access, foundation readiness, and coordination with civil and electrical teams are also reviewed to avoid rework and delays.
3️⃣ What is preventive maintenance?
Answer:
Preventive maintenance is planned maintenance performed at regular intervals to prevent equipment failure. It includes inspections, lubrication, tightening, alignment checks, and part replacement. This approach improves equipment life, reduces breakdowns, and ensures smooth plant operation.
4️⃣ What is corrective maintenance?
Answer:
Corrective maintenance is performed after a failure occurs to restore equipment to operational condition. It involves fault identification, root cause analysis, repair or replacement of damaged parts, and testing before commissioning. Proper corrective action prevents recurrence of failures.
5️⃣ What is a plant shutdown?
Answer:
A plant shutdown is a planned stoppage of operations to carry out maintenance, inspection, modification, or replacement of equipment. Shutdowns require detailed planning, safety control, coordination of multiple teams, and strict adherence to timelines to minimize production loss.
6️⃣ What is piping isometric drawing?
Answer:
An isometric drawing represents piping in a 3D view showing dimensions, fittings, valves, supports, and weld details. It helps fabrication and site teams understand routing, spool fabrication, and erection sequence clearly.
7️⃣ Difference between fabrication and erection?
Answer:
Fabrication involves manufacturing components in a workshop using drawings. Erection is the process of installing fabricated items at site. Fabrication ensures quality and speed, while erection focuses on alignment, fitment, and integration with existing systems.
8️⃣ What is hydrostatic testing?
Answer:
Hydrostatic testing checks the strength and leak tightness of piping or pressure vessels by filling them with water and applying pressure. It ensures system integrity before commissioning and prevents failures during operation.
9️⃣ What is the importance of alignment in rotating equipment?
Answer:
Proper alignment between motor and pump shafts reduces vibration, bearing wear, seal failure, and energy loss. Poor alignment leads to frequent breakdowns and reduced equipment life. Alignment is checked using dial gauges or laser tools.
🔩 PIPING & MECHANICAL SYSTEMS
🔟 What are common piping materials used in plants?
Answer:
Common materials include carbon steel, stainless steel, alloy steel, and special materials depending on service conditions like temperature, pressure, and corrosion. Material selection ensures safety, durability, and compliance with process requirements.
1️⃣1️⃣ What is stress analysis in piping?
Answer:
Stress analysis evaluates piping behavior under thermal expansion, pressure, and external loads. It ensures stresses are within allowable limits to prevent leakage, deformation, or failure during operation.
1️⃣2️⃣ What is the purpose of pipe supports?
Answer:
Pipe supports carry weight, control movement, and reduce stress due to expansion or vibration. Proper support design prevents sagging, misalignment, and damage to equipment or piping systems.
1️⃣3️⃣ What is hot work?
Answer:
Hot work includes welding, cutting, grinding, or any activity producing heat or sparks. It requires special permits, fire watch, gas testing, and safety precautions to prevent fire or explosion.
1️⃣4️⃣ What is cold work?
Answer:
Cold work includes activities like bolting, fitting, or mechanical assembly that do not generate sparks or heat. Though safer than hot work, proper permits and safety checks are still required.
1️⃣5️⃣ What is a pressure vessel?
Answer:
A pressure vessel is a closed container designed to hold fluids at pressures different from ambient pressure. It is designed as per codes to ensure safe operation under high pressure and temperature.
⚙️ ROTATING EQUIPMENT
1️⃣6️⃣ What causes pump cavitation?
Answer:
Cavitation occurs when pressure at pump suction drops below vapor pressure, causing vapor bubbles that collapse violently. It damages impellers, reduces efficiency, and causes vibration and noise.
1️⃣7️⃣ How do you prevent pump cavitation?
Answer:
Ensure proper NPSH, correct suction piping design, adequate liquid level, clean strainers, and proper pump selection. Regular inspection helps prevent cavitation-related failures.
1️⃣8️⃣ Difference between centrifugal and positive displacement pumps?
Answer:
Centrifugal pumps use velocity to move fluid and are suitable for large flow rates. Positive displacement pumps move fixed volumes and are used for high-pressure or viscous fluids.
1️⃣9️⃣ What is vibration analysis?
Answer:
Vibration analysis monitors equipment condition by measuring vibration levels. It helps detect imbalance, misalignment, bearing failure, and mechanical looseness before major failure occurs.
2️⃣0️⃣ What is lubrication management?
Answer:
Lubrication management ensures correct lubricant type, quantity, and interval. Proper lubrication reduces friction, heat, and wear, improving equipment life and efficiency.
🧰 SAFETY & QUALITY
2️⃣1️⃣ What is Job Safety Analysis (JSA)?
Answer:
JSA identifies hazards associated with a job and defines control measures. It improves awareness, reduces accidents, and ensures safe execution of mechanical activities.
2️⃣2️⃣ Why is PPE important in mechanical work?
Answer:
PPE protects workers from hazards like cuts, burns, noise, and falling objects. Proper use of helmets, gloves, goggles, and safety shoes reduces injury risk.
2️⃣3️⃣ What is LOTO?
Answer:
Lock Out Tag Out ensures equipment is isolated and cannot be energized during maintenance. It prevents accidental startup and protects maintenance personnel.
2️⃣4️⃣ What is quality inspection in mechanical construction?
Answer:
Quality inspection ensures work meets drawings, specifications, and standards. It includes dimensional checks, welding inspection, material verification, and testing.
2️⃣5️⃣ What is WPS and PQR?
Answer:
WPS defines welding parameters, while PQR validates welding procedure performance. Both ensure weld quality and compliance with codes.