International Ductile Iron Pipes Co Ltd - Essay Example

? Internship Report International Ductile Iron Pipes Co. Ltd (INDIPCO) College: Presented Table of Contents Table of Contents 2 0 Introduction 3 1.1 Company Background 3 1.2 Current main Projects 3 2.0 Plant operation Process 4 2.1 Mold Preparation and Maintenance. 4 2.2 Molten iron Preparation 5 2.3 Centrifugal casting 5 2.4 Making cores 6 2.5 Annealing 6 2.6 Hydrostatic testing and finishing 7 2.6.1 Zinc coating process. 8 2.6.2 Cement coating 8 2.6.3 Bitumen coating 9 2.7 Marking, Parking and Shipping 9 2.8 Tests on Pipes 9 3.0 Knowledge Gained 10 3.1 Materials, Process and Applications 10 3.2 Process Automation 12 3.3 Management style 13 4.0 Conclusion and Recommendations 14 5.0 Work Cited 14 INDIPCO Internship Report 1.0 Introduction 1.1 Company Background International Ductile Iron Pipes Co. Ltd (INDIPCO) is an associate member of FAL Group of Companies. The group specializes in the manufacture of large ductile iron pipes with diameters ranging from 100mm to 2200mm. The company is located within the Royal Commission of Yanbua and Jubail in Jubail industrial city, covering an area of about 155,000m2. The company has an estimated production of about 200,000 tons of pipes annually. The company has its main customers within the Kingdom, in Europe and the MENA region. All INDIPCO processes are highly developed with the most current state of the art technologies, with its main equipment mainly sourced from Germany, China, USA and other leading technological states. All the equipment is installed and tested for a period of time under the supervision of experts from the above counties, to ensure the machine performs optimally with little hiccups in its systems. Generally, any experts involved in the maintenance and installation processes are highly conversant with ductile iron pipes plants, to ensure quality and high standards are maintained within the company. The pipes manufactured and exported by INDIPCO are mainly used for water, firefighting, sewerage, effluents slurries, industrial water, and other fluids, meaning the company has a wide variety of pipes that target different clients in different segments. 1.2 Current main Projects The company undertakes massive water transmission projects portraying its expertise and skills in pipe manufacture and water and fluid transmission. An example of such an large scale projects still ongoing are a water transmission system covering an approximately 74,000 linear meters of pipes from Hali, Qanona, AL-Laitha and Yebh dams to AL Shoiba, which covers the phase one of the project. Another project is installation of suction lines for reservoirs in AL Madina covering a length of 134.2 km (INDIPCO, 2012). The company has therefore carved its reputation from handling mega projects in fluid transmission and manufacture of different grades of pipes to transmit different fluids both corrosive and non-corrosive. 2.0 Plant operation Process Fig. 1Pipe Manufacturing process The chart above summarizes the entire plant operation process in iron ductile pipe manufacturing to storage of finished pipes. 2.1 Mold Preparation and Maintenance. Mold making requires machines for mold welding, gridding and peening, and a lathe machine. Molds are used over and over till they wear out and fail to produce the required dimensional accuracy. After each, shift, the mold has to be replaced and maintained. The internal surface of the mold has to be ground using a sand wheel to remove any rust. The mold is then dotted with peening head to increase its crack resistance, and to improve its adhesion properties. All cracks on the internal surface of a mold have to be removed through turning, after which the turned area is welded and excess metal turned again to maintain the required dimensional controls. Grinding and peening ensure the mold finally has a smooth surface and is free from any cracks that may impair its usability. 2.2 Molten iron Preparation Molten iron, scrap steel, alloy and any rejected pipes are melted at this stage. The melting equipment is a two and three coreless furnaces with each furnace accommodating tense of tons, and a total capacity of about 50 tons per hour. The raw materials are put into the furnace in definite proportions and temperature raised to between 1460 to -1520oC. The molten iron, which complies with the required standards, is then spheroidised by putting a spheroidising agent at the bottom of ladle before pouring the molten iron into the ladles. After this, the spheroidised molten iron is transported to a casting platform while covered with pearlite to prevent any reaction with atmospheric water and oxidation of the molten metal. 2.3 Centrifugal casting The process involves equipment with four water cooling centrifugal casting machines. These machines are arranged as follows; two machines for DN80-300mm standard pipes, one machine for the DN400-700mm pipes, and one machine for DN800-1200 pipe standards respectively. The molten iron from ladles is poured into a volumetric tilting ladle. The molten content enters the mold spinning cavity at high speeds, with cooling water running along a trough. The molten iron then cools and solidifies on a pipe. The complete pipe is then extracted by an extractor, and transported for annealing in an annealing furnace. The rate of pouring metal controls the thickness of the pipe. The centrifugal force produced by the high seed rotation of the mold cavity holds the pure metal against the walls of the mold; while lighter particles that form impurities are forced inside the pipe where they are removed later in the cleaning process. 2.4 Making cores Eh core making equipment involves a four core making jets alongside hot core boxes. Two of the jets form a dual workstation, while two form a single workstation. The system also includes two manual core making jets. Core making uses silicon sand, resin, and solidified agent, mixed according to specified proportions, rolled, and then inserted in the hopper to the machine. The mixture is then poured into the core boxes. Cores are made after the mixture is heated and solidified through a sintering process, where the resin melts and holds the silicon sand particles together strongly. Cores are then tested thoroughly after solidifying, and those which meet standards are conveyed to the casting area. 2.5 Annealing The annealing equipment involves a furnace in a horizontal chain of continuous annealing stages. The furnace is 52meters long and is made of a heating section, a section to hold the pipe in the heated temperature, a section to cool the pipe slowly, and a fast cooling section. The cast ductile pipes once entered in eh annealing furnaces are then rolled forward by claws controlled by chains, which are driven by a DC motor. The speed of the motor can be regulated according to the annealing rate required. The furnace is fitted with many meters to read and control the temperatures automatically. The figure below portrays the annealing curve required for ductile iron pipes. 2.6 Hydrostatic testing and finishing After annealing pipes have to undergo a finishing process. The finishing process involves removing spigot ends, bell, and finishing the external and internal sections of the pipe by removing fines and other unwanted materials. The pipes are then checked for conformity with the required dimensions. After the finishing process, the pipes are then checked for water pressure one pipe after another to ensure each produced pipe meets the required fluid pressure standards. The pressure standards tested at the hydrostatic testing stage are as follows: 5MPa for pipes in DN100- 300 class, 4MPa for DN350-600 class, and 3.5MPa for the DN700pipe class. Each pipe is exposed to the testing pressure for 10 seconds only after which it is dismounted. All pipes that meet the above standards are then coated accordingly in preparation for delivery to fluid transmission area. It is important to note that pipes are coated according to the preference of the specific client. Coating may involve: zinc coating, cement mortar lining, and bitumen coating. Mainly, the type of coating will depend on the fluid to be transmitted by the pipes, and its corrosive nature. 2.6.1 Zinc coating process. The zinc coating machine melts zinc through an electric arc, and applies the zinc on the external surface of pipes. The zinc layer has to be maintained even, and has to adhere strongly on the pipe, which is tested by a digital meters to show the thickness of the coating layer. Any difference in the thickness of the pipe is corrected by adjusting the computer program controlling such zinc coating processes. 2.6.2 Cement coating This process involves mixing sand, cement and water according to definite proportions and the mixture stirred thoroughly. The mixture is then pumped into a pipe spinning at low speeds. The pipe is the moved ingot the high speed section where it is supposed to discharge any excess water and ensure the deposit of the mortar is dense as required. The pipes are then dried naturally, and smoothed with a grinder after the mortar dries up and solidifies into a compact layer of coating. 2.6.3 Bitumen coating Bitumen coating is mainly applied in pipes that need to transmit corrosive fluid. The anti-corrosive layer of bitumen is applied on the external and internal surfaces of the socket, and has to be evenly distributed without any possibility of the bitumen dropping or flowing. 2.7 Marking, Parking and Shipping After the pipes have passed all the processes, they are tested to ensure they are in accordance with the required international standards, marked at spigot and the company’s trademark placed on every pipe. Pipes are then packed in bundles with thick wood pieces between, and tightened with steel belts to make them ready for shipment. 2.8 Tests on Pipes In the course of the above pipe manufacturing process, other tests are carried out to ensure the produced pipes meet the required mechanical properties and strengths. For example, pipes are selected randomly at intervals of about three hours, and tensile tests are carried out to determine whether each batch of pipes meets the required tensile properties. Other tests include the impact tests done at least ones after every hour. The testing sample is machined from the pipe walls. Impact test ensures pipes adhere to the required toughness, especially in high pressure liquid transmission. Hardness tests are further carried out at intervals to ensure pipes are resistant to corrosion and pitting. Generally, quality control in the pipe a manufacturing process involves analyzing raw materials, analyzing the chemical composition of the pipes, controlling temperatures, analyzing the microstructures of the pipe, and the extent to which all pipes and materials meet the mechanical and structural properties. All the processes are managed under ISO 9001:2008 quality management standards. 3.0 Knowledge Gained From the internship, much was learnt in application of learned engineering theoretical concepts. INDIPCO has all its operations in line with industrial engineering applications, which is my major area of study. The implication of each process in pipe making, the tests carried out through the processes, the management process, and factory system management were very significant and imperative to learn as a prospecting industrial engineer. 3.1 Materials, Process and Applications The main lesson was the principle behind the use of flexible ductile iron, which is preferred over other types of pipes. The lesson was that ductile iron pipes have a high yield, high impact resistant, high strength, high fatigues resistance, resistance to handling and transportation damage, simple to join when the joint deflection agree, they resist longitudinal joint withdrawal thus making them useful for high pressure fluid transmission. Moreover, these pipes are impermeable to gas and organic contaminates, they are easy to locate when buried, they can be connected under pressures easily, and are resistant to the effects of stray current due to electrical discontinuity at joints. To ensure impermeability, the company uses the latest hot and cold core box making machines. These machines allow precise control of sand and other additives in the processes, resulting in highly rigid cores. The rigid cores result into increased precision in socket dimensions which lead to perfect fitting between the flange and sockets, preventing any cases of leakage. The company has thus invented more on core making, which is basic to obtaining high quality pipes. Pattern making in any production activity was noted to be instrumental in obtaining quality final products. These properties make the pipes ideal for distributing water and gas, transmitting industrial and domestic effluent that are corrosive, under major carriage ways, applications in ground conditions prone to movements in earth quake prone areas, or mountainous areas, among other major usages, make such ductile pipes versatile in fluid transmission. All the pipes are produced with flanges at one end, and sockets on the other end. The significance of this is that the push on flexible joint offers extra strength and much efficiency, making it versatile in the usage detailed above. In this case, the flange ensures that no bolts or screws are required but just a push on with a rubber gasket in between. Each pipe is therefore separate, making it easy to lay pipes even in wet conditions, and eliminating any electric current due to discontinuity at joints. The different initials found on pipes were noted and their significance and principle understood. For example, it was noted that all pipes have to be supplied in a length of 5.5 meters except on special request by customers, with the thickness of a particular pipe being determined through the formula e=k(0.5+0.001DN). Important specifications in pipes and their significance were noted. These included: PFA, referring to the allowable operating pressure or the internal pressure that a pipe can accommodate safely PMA is the allowable maximum operating pressure and refers to the maximum allowable pressure in a pipe including surge pressure that a pipe can withstand. Finally, PEA implies the allowable test pressure, which is the maximum hydrostatic pressure that any newly installed pipe may withstand for a short duration, either on ground or underground, while maintaining the tightness or in integrity of the pipe. These parameters are critical for any industrial engineering application; they determine the safety level that any particular pipe can operate in. Generally, ductile iron pipes were observed to be different from ordinary gray iron pipes due to their remarkable mechanical properties as indicated. The improved mechanical properties are due to the spheroidal nature of graphite molecules. Importantly, during the metal preparation stage, as molten metal is poured into ladles, pure magnesium is added at controlled conditions. The pure magnesium ensures nodularity of graphite, impacting increased tensile strength, ductility, and tightness. Therefore, magnesium impacts the most remarkable properties of ductile iron pipes compared to non-ductile iron pipes. Magnesium is thus a critical element in the ductile pipe manufacturing process that helps to improve granulation of the metal matrix, impacting superior properties to such pipes. 3.2 Process Automation The extensive use of PLC systems in the factory operations was noted to be the principle behind smooth operations and ease of process management in the pipe manufacturing process. The use of PLC impacted flexibility in running multiple machines, the ease to correct errors which only requires retyping the logic, PLCs are space efficient in having numerous contact timers, sequencers, counters and other elements within a single PLC, the ease to test each program in PLC and the ability to visualize the entire process from a control panel made the pipe manufacturing process more convenient. The ability to follow the entire process from the control process facilitates easier trouble shooting of the entire factory, where problems are identified and dealt with in advance before system breakdown. Heavy reliance on PLC in the industry was thus noted as key in making the factory to operate optimally with much less staff. For example, from the control panel, the operators could change the speed at which pipes were rolled within the furnace affecting the ferrite formed in pipes to improve ductility and other mechanical properties. The heat treatment process was thus varied from the control room though PLCs, which controlled the conveyor chain, ensuring the treatment proceeded with great control. Therefore, when companies capitalize on high manufacturing technologies, the company performs optimally without any cases of systems breakdown, or interruptions. On process maintenance activities where engineers troubleshoot the entire pipe making process, and physically assess operations of critical areas such as DC motors, driving chains, pumps, and conveyors saves a company great cost. Breakdown maintenance implies the production has to stop for parts to be serviced, which may cost the company many lost production hours. The advanced troubleshooting process and ability of engineers to troubleshoot the entire plant made it possible to identify areas of weaknesses, and taking the necessary measures to avoid system breakdown. Moreover, the company observed strict quality control procedures which ensured all pipes met all the UN and BS standards specifications. Quality control was not carried out as a last activity but was integrated in the production process from testing the composition of the molten metal, controlling the amount of magnesium added to enhance formation of granules, testing the spun pipe before zinc coating, and all structural and mechanical tests done before finishing off the pipes for delivery. The quality control processes were in accordance with Kaizen practices, advocate for processes improvement as the job continues. 3.3 Management style Team playing, a flatter hierarchy of management and elaborate dispute and mechanism were all management system that was noted to have impacted positively on the operations of the company. Instead of the pyramid management structure, the company management was very friendly and listening to workers, with consistent discussions on how to improve processes held regularly. Generally, the company employees considered themselves as members of a larger family and increased respect and understanding was noted among the subordinates and their managers. Therefore, it was noted that treating employees with dignity and satisfying their needs was key to success in a business. 4.0 Conclusion and Recommendations The entire internship was a great success that resulted in elaborate integration of theoretical concepts learned in class into practical industrial engineering applications. It would be recommended that future internship programs be made longer and be changed to after completion of the engineering course. This would make it possible for firms to offer internship programs, offer effective training, and consider such trainees for employment opportunities to apply the learned skills. 5.0 Work Cited INDIPCO, International Ductile Iron Pipes Co. Ltd, 2009 http://www.indipco.com/ (Accessed 2nd April 2013) Read More