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The Field Work Practice (PKN) carried out at PT MK Prima Indonesia focused on the implementation of periodic maintenance practices for the premoulding hydraulic press machine as an effort to maintain machine performance and operational lifespan. The main activities included identifying critical components such as the hydraulic system, valves, pressure hoses, and oil filters; conducting direct observation of common disruptions; and performing daily maintenance checklists that covered pressure monitoring, operating temperature, leakage detection, machine cleanliness, and lubrication conditions. Comprehensive cleaning procedures, condition-based filter replacement, and functional testing were also conducted to ensure reliability and safety in the production process. The implementation methods involved participatory observation, interviews with technicians regarding common failure patterns, visual and functional inspections, as well as the use of structured checklists supported by inspection documentation. The results indicate a significant decrease in the frequency of disturbances caused by leaks and oil contamination, improved compliance with routine inspection procedures, and enhanced machine readiness during operations. The introduction of structured documentation and simple technical training further improved technicians’ ability to detect early signs of abnormalities in the hydraulic system. As a recommendation, the company is advised to strengthen the use of digital recording systems, adjust filter replacement intervals based on actual machine conditions, and implement regular training programs focusing on contamination control and predictive maintenance.

The Field Work Practice (PKN) carried out at PT MK Prima Indonesia focused on the implementation of periodic maintenance practices for the premoulding hydraulic press machine as an effort to maintain machine performance and operational lifespan. The main activities included identifying critical components such as the hydraulic system, valves, pressure hoses, and oil filters; conducting direct observation of common disruptions; and performing daily maintenance checklists that covered pressure monitoring, operating temperature, leakage detection, machine cleanliness, and lubrication conditions. Comprehensive cleaning procedures, condition-based filter replacement, and functional testing were also conducted to ensure reliability and safety in the production process. The implementation methods involved participatory observation, interviews with technicians regarding common failure patterns, visual and functional inspections, as well as the use of structured checklists supported by inspection documentation. The results indicate a significant decrease in the frequency of disturbances caused by leaks and oil contamination, improved compliance with routine inspection procedures, and enhanced machine readiness during operations. The introduction of structured documentation and simple technical training further improved technicians’ ability to detect early signs of abnormalities in the hydraulic system. As a recommendation, the company is advised to strengthen the use of digital recording systems, adjust filter replacement intervals based on actual machine conditions, and implement regular training programs focusing on contamination control and predictive maintenance.

This study discusses the effect of valve weight and clearance on the efficiency of a hydraulic ram pump, with a focus on optimizing water discharge efficiency in the Sumberingin Tourism Area, Wringinsongo Village, Tumpang, Malang Regency. The method used in this study is an experiment with variations in valve weight consisting of 10 kg, 11 kg, and 12 kg, as well as valve clearances varying between 16.5 mm, 24.5 mm, and 32.5 mm. The results showed that the combination of a valve weight of 10 kg and a clearance of 16.5 mm produced the highest water discharge efficiency, namely 69.7 liters per minute, with an optimal efficiency of around 33%. In the optimization process, the application of Design of Experiment (DOE) revealed that a valve weight of 11 kg and a clearance of 16.5 mm can produce a maximum discharge efficiency of 63.155 with a desirability value reaching 0.7671. These findings indicate that proper settings on valve weight and clearance can contribute significantly to increasing the efficiency of a hydraulic ram pump. This research provides valuable insights into improving the performance and reliability of hydraulic ram pumps in rural water distribution systems. Understanding the influence of these variables is expected to yield more effective solutions for water resource management, particularly in areas requiring efficient irrigation systems. Furthermore, this research also opens up opportunities for further research on hydraulic ram pump optimization by considering other factors that can influence the efficiency and performance of the overall water distribution system. It is hoped that the results of this research can serve as a reference for the development of more efficient and environmentally friendly hydraulic ram pump technology, as well as supporting the sustainability of water resource management in rural areas.

Accurate evaluation of head losses is essential in industrial systems transporting viscous chemical fluids, such as sodium hydroxide (NaOH), to ensure hydraulic efficiency and operational reliability, particularly in chlor alkali plants. This study analyses major and minor flow losses in the NaOH piping system at PT X Chlor Alkali Plant, Porsea, and evaluates the pipe design's hydraulic feasibility. After defining system parameters—including fluid properties, pipe geometry, and the number and type of fittings—technical calculations were conducted to assess flow profiles and pressure losses along two main pipe routes. A quantitative analysis using the Moody diagram and operational data reveals that minor losses dominate, contributing over 75% of total head loss in both routes. The total head loss remains within the pump's rated capacity (18 m), though with a narrow margin. A pipe diameter of 0.114 m produces a flow velocity of 0.79 m/s, aligning with recommended industrial standards for corrosive fluids. The use of Sch.80 stainless steel proves effective in minimizing frictional losses, particularly under turbulent flow conditions. These findings highlight the critical role of fitting configurations and material selection in optimizing chemical process piping systems.

Pressure measurement is a fundamental aspect of mechanical engineering used to monitor and control various fluid and mechanical systems. This study discusses different pressure measurement methods, including the use of manometers, pressure transducers, and microcontroller-based sensors. Experimental methods were conducted to compare the accuracy and sensitivity of various measuring instruments in different testing environments, such as hydraulic systems, pneumatic systems, and internal combustion engines. The results show that microcontroller-based sensors provide high accuracy and easy integration with industrial automation systems. Additionally, environmental factors such as temperature and vibration significantly affect the accuracy of pressure measurements. This study provides insights into the advantages and limitations of each method and recommendations for optimal applications in mechanical engineering.

This study analyses the Froude number and type of hydraulic jump in flow through a sluice gate in a secondary channel, both with and without a wide sill. Culverts, as important hydraulic elements in irrigation systems, often trigger hydraulic jumps that have the potential to cause scour. This research is motivated by the need to understand the characteristics of hydraulic jumps in more detail, as a basis for designing effective energy dissipators. Unlike previous studies that focus on contraction coefficient and discharge, this study specifically examines the Froude number and classification of springboard types. This study used secondary data from Sunik's (2001) research which included discharge, water level and flow velocity data for two channel configurations: with and without wide sill. The analysed discharge data varied from 10 to 30 litres/second with variations in door opening. The analytical method used was the calculation of Froude number based on secondary data to classify the type of hydraulic jump. The objectives of this study were to determine the Froude number value and identify the type of hydraulic jump that occurred. The findings showed that discharge and door opening influenced flow characteristics and springboard type. In channels without a sill, discharge affects the transition of flow from subcritical to supercritical. The presence of a wide sill creates a more linear relationship between water level, velocity and Froude number. Varying the door opening affects the type of surge, from choppy, to weak, to vibrating, as the flow energy increases. Larger discharges resulted in higher Froude numbers and stronger surge types. This research makes an important contribution to the understanding of hydraulic springing phenomena and the design of energy dissipator.

This research investigates the potential of integrating waste heat recovery and geothermal exchange within district heating systems as a carbon-neutral energy solution tailored to tropical urban settings. Tropical climates present unique challenges for heating, ventilation, and air conditioning (HVAC) systems, including high humidity, temperature fluctuations, and increasing energy demands, particularly for cooling. This study aims to address these challenges by proposing a hybrid district heating system that combines renewable energy sources to improve energy efficiency and reduce carbon emissions. The methodology includes thermal and hydraulic modeling, performance simulation of the hybrid system under tropical climate conditions, and emission and energy efficiency analysis. The results indicate that the hybrid system significantly reduces energy consumption and carbon emissions compared to traditional heating systems, with waste heat recovery optimizing energy use and geothermal exchange enhancing system efficiency. The comparison with conventional systems and other environmentally friendly alternatives reveals that the hybrid system offers a cost-effective, sustainable solution for tropical urban areas. The study concludes that integrating waste heat recovery and geothermal exchange is feasible and can contribute to the creation of carbon-neutral cities. Future research should focus on optimizing geothermal systems in tropical climates and exploring further integration with other renewable energy sources to enhance system performance and sustainability.