CHIEF ENGINEER Unit 14 Condition Monitoring Q1

Plant monitoring, in the context of a planned maintenance system, refers to the continuous or periodic observation and measurement of various parameters and conditions of machinery, equipment, and systems within a plant or facility. The goal is to gather real-time or near-real-time data on their performance, health, and operating conditions to enable proactive maintenance decisions and optimize overall maintenance strategies.  

1. Why Your Plant Needs Predictive Maintenance Software? – Power-MI

Key Elements of Plant Monitoring:

• Data Collection: Involves using various sensors, instruments, and monitoring devices to collect data on parameters like temperature, pressure, vibration, flow rates, oil condition, and other relevant metrics.   1. Plant Monitoring | Overview | Wikifactory wikifactory.com
• Data Analysis and Interpretation: The collected data is analyzed and interpreted to identify trends, anomalies, or deviations from normal operating conditions that might indicate potential issues or impending failures.   1. How does data analytics improve plant productivity? – IBITEK Group www.ibitek-group.com
• Decision-Making: The insights from data analysis are used to make informed decisions regarding maintenance actions, such as scheduling preventive maintenance, predicting component lifespans, or identifying the need for immediate repairs.   1. Data-Driven Maintenance Revolution: Insights for Smarter Decision Making www.maintwiz.com

Types of Plant Monitoring:

• Condition Monitoring: Focuses on monitoring specific parameters of machinery and equipment to assess their health and predict potential failures. Examples include vibration analysis, oil analysis, thermography, and acoustic emission testing.   1. What is Condition Monitoring? – Bently Nevada – Baker Hughes www.bakerhughes.com2. What is Condition Monitoring? – Process Parameters Ltd www.processparameters.co.uk
• Performance Monitoring: Tracks overall system or equipment performance to identify any degradation or inefficiencies. This may involve monitoring energy consumption, throughput, or product quality.   1. 5 Benefits of Plant Efficiency Monitoring System – OptiSol Business Solutions www.optisolbusiness.com
• Environmental Monitoring: Monitors environmental conditions that might impact equipment performance or safety, such as temperature, humidity, or air quality.

Benefits of Plant Monitoring in a Planned Maintenance System:

• Predictive Maintenance: By identifying potential issues early, plant monitoring enables a shift from time-based to condition-based maintenance, performing maintenance only when necessary based on actual equipment condition.
• Reduced Downtime and Costs: Prevents unexpected breakdowns and associated downtime by addressing potential failures before they occur, leading to cost savings and improved operational efficiency.   1. Plant Maintenance: What It Is, Benefits, and More! – Facilio facilio.com
• Enhanced Safety: Helps identify and address safety hazards proactively, reducing the risk of accidents and equipment failures.   1. Safeguarding Your Plant Efficiency: Proven Methods for Preventing Equipment Failures www.maintwiz.com
• Improved Efficiency: Optimizes maintenance schedules based on actual equipment condition, resulting in improved overall performance and reduced energy consumption.   1. How to Implement Predictive Maintenance with Production Monitoring – Mingo Smart Factory www.mingosmartfactory.com
• Better Resource Management: Allows for better planning and allocation of manpower, spare parts, and other resources, leading to cost savings and improved maintenance efficiency.

In Summary:

Plant monitoring is a crucial component of a modern planned maintenance system. By leveraging technology to gather and analyze data on machinery and equipment performance, it empowers maintenance teams to make informed decisions, implement proactive maintenance strategies, and ultimately improve the safety, reliability, and efficiency of industrial operations.

During a full overhaul of a marine diesel engine, several key components of a single main engine unit would be calibrated or measured to ensure they are within manufacturer’s specifications and operating optimally. Here’s a list of some of those components:

Cylinder Liner:

• Bore Diameter: The internal diameter of the liner is measured at various points along its length to check for wear, ovality, or any other deformation that could affect the piston’s fit and sealing.
• Surface Finish: The surface finish of the liner is also inspected to ensure proper lubrication and prevent excessive wear on the piston rings.

Piston:

• Crown Clearance: The distance between the piston crown and the cylinder head at Top Dead Center (TDC) is measured to ensure proper combustion and prevent contact.
• Ring Grooves: The dimensions of the piston ring grooves are checked for wear and to ensure proper fit and sealing of the piston rings.
• Piston Skirt Clearance: The clearance between the piston skirt and the cylinder liner is measured to allow for thermal expansion and prevent seizure.

Piston Rings:

• Butt Clearance: The gap between the ends of the piston rings when installed in the cylinder is measured to ensure proper sealing and prevent gas blow-by.
• Radial Thickness: The thickness of the piston rings is checked to ensure they meet specifications and provide adequate sealing.
• Axial Clearance: The clearance between the piston rings and their grooves is measured to allow for proper movement and oil control.

Connecting Rod:

• Bearing Clearances: The clearances between the connecting rod bearings and the crankshaft journals are checked to ensure proper lubrication and prevent excessive wear.
• Big End Bolt Tightness: The tightness of the connecting rod big end bolts is verified using a torque wrench to ensure secure fastening and prevent failure.

Cylinder Head:

• Valve Clearances: The clearances between the valve stems and their guides are adjusted to ensure proper valve operation and prevent leakage.
• Fuel Injector: The fuel injector is calibrated and tested to ensure it delivers the correct amount of fuel at the right time and pressure for efficient combustion.

Other Components:

• Exhaust Valve: The exhaust valve seating and clearances are checked to prevent gas leakage and ensure proper operation.
• Fuel Pump: The fuel pump is calibrated and tested to ensure it delivers the correct amount of fuel to the injectors.   1. How to Calibrate Diesel Injection Pump – Goldfarb & Associates Inc goldfarbinc.com
• Governor: The governor is adjusted and tested to ensure it maintains the desired engine speed and load.
• Turbocharger: The turbocharger is inspected for wear and damage, and its bearings and seals are checked for leaks.   1. Turbo Charging Marine Engines Maintenance Turbochargers -surging, | by shambhu yadav shamyadav.medium.com

Calibration and Measurement Tools:

• Micrometers: Used for precise measurement of internal and external diameters, such as cylinder liner bore and piston ring groove dimensions.
• Bore Gauges: Specialized tools for accurately measuring cylinder liner bore diameters.   1. EP2192381A1 – A method of measuring cylinder liner diameter in a two-stroke crosshead internal combustion engine, a diameter gauge device, and a flexible ring for use in the method – Google Patents patents.google.com
• Feeler Gauges: Used to measure clearances between various components, such as piston rings, bearings, and valves.
• Torque Wrenches: Used to apply the correct torque to critical fasteners, such as connecting rod big end bolts.
• Specialized Testing Equipment: Depending on the specific components, other specialized testing equipment may be used, such as fuel injector test benches, valve spring testers, and turbocharger balancing machines.

By carefully calibrating and measuring these critical components during a full overhaul, engineers ensure that the main engine unit is restored to its optimal operating condition, promoting efficient and reliable performance while minimizing the risk of breakdowns or failures.

High levels of tin and lead in a crankcase oil sample are indicative of wear in bearing components. These metals are commonly used in bearing alloys, specifically in the overlay or babbitt layer of plain bearings. Therefore, the following parts of the engine would require examination:

1. Main Bearings: These bearings support the crankshaft within the engine block and are subject to high loads and continuous rotation. Wear in these bearings would release tin and lead particles into the oil.   1. Main bearing – Wikipedia en.wikipedia.org
2. Big-End Bearings: Located at the connecting rod’s larger end, these bearings connect the connecting rod to the crankshaft. They also experience significant loads and rotational forces, making them susceptible to wear.   1. Engine Bearings – FAI Auto Parts www.faiauto.com
3. Small-End Bearings: These bearings connect the connecting rod to the piston pin. Although they experience less load compared to main and big-end bearings, wear can still occur, contributing to tin and lead contamination in the oil.   1. Small End Bearing reinforced – MAXISCOOT.com www.maxiscoot.com
4. Thrust Bearings: These bearings control the axial movement of the crankshaft and are particularly important in engines with large propellers. Wear in thrust bearings can also release tin and lead particles.   1. Thrust Bearings Guide: Types, Features, Applications iskbearing.com
5. Camshaft Bearings: The camshaft bearings support the camshaft, which controls the opening and closing of valves. Wear in these bearings, although less common, can also contribute to the presence of tin and lead in the oil.   1. Cam Bearings – Pep Boys www.pepboys.com

Additional Considerations:

• Oil Cooler: In some cases, high tin and lead levels could be related to leaching from solder used in oil cooler tubes. If there’s a concurrent increase in oil acidity or evidence of coolant contamination, the oil cooler should also be inspected.   1. Sources of Lead – TestOil testoil.com
• Recent Maintenance: If the engine has undergone recent maintenance or repairs, the elevated levels of tin and lead could be due to residual contamination from assembly lubricants or anti-seize compounds. However, this should decrease with subsequent oil changes.   1. Sources of Lead – TestOil testoil.com

Examination Procedure:

The examination of these components typically involves:

• Visual Inspection: Checking for signs of wear, scoring, discoloration, or overheating on the bearing surfaces and journals.
• Clearance Measurements: Measuring bearing clearances using feeler gauges or other specialized tools to determine if they are within acceptable tolerances.   1. Measuring Main Engine Bearing Clearances – Nautilus Shipping www.nautilusshipping.com
• Non-Destructive Testing (NDT): In some cases, NDT techniques like ultrasonic testing or magnetic particle inspection may be employed to detect cracks or other internal defects in the bearings or journals.

Further Actions:

If significant wear or damage is found in any of the bearing components, they should be replaced or repaired to prevent further engine damage and ensure its continued reliable operation. It’s also important to investigate the root cause of the bearing wear, which could be related to lubrication issues, misalignment, overloading, or other operational factors. Addressing the root cause is essential to prevent recurrence and ensure the long-term health of the engine.