General Overhaul as а Base for Stable Operation of Equipment

One of the conditions for the efficient operation at any enterprise is the availability of a well-functioning mechanism for performing repair works. The lower share of expenses for the equipment maintenance and repair in the cost of production ensures the higher manufacturing efficiency. The preventive maintenance (PM) system is the best way to prevent irrational production losses and to reduce the overhaul costs.

The PM system is a set of various works, aimed to technical maintenance and equipment repair, performed according to prearranged plan. In terms of maintenance content, complexity and frequency, scheduled repairs are divided into current, average and general overhaul, where the last one is the most expensive and time-consuming process. Conducting of general overhaul is a great achievement of DPL.

Summing up the results of the recent overhaul, we would like to admit the high level of responsibility, discipline and qualification of the maintenance team. Due to the availability of organizational practice and financial arrangement all planned works were performed efficiently under normal operating conditions. Main overhaul results by sectors are presented below.

Molding department. All inserts and other FBO spare parts have been replaced. It will ensure precision of the machine during blend molding and, accordingly, reduce the quantity of defective products. In addition, the such kind of works were performed, which with minimal financial investment are very costly in terms of time and human resources. Thus, Chief Power Engineer and Instrumentation Automation Engineer conducted a revision of all electrical sensors, performed modernization of molding machine in order to increase its reliability by installing a special supplementary unit. The achievement of casting conveyor highest efficiency became possible as well due to overhaul performance at DPL.

Sand-blending unit. The mixer and supplementary mechanisms (elevators, conveyor belts, etc.) have been repaired, which will ensure uninterrupted operation of the sector for the next working period. Should be mentioned that the buckets were manufactured by DPL own forces (from the creation of the mold till the direct manufacturing).

Melting department. An revision of 4 TFC (thyristor frequency converters) was performed, water pool for furnace cooling was cleaned. According to the results: up to 3 m3 of sediment were eliminated (the previous cleaning was performed last spring). Also, our own distiller for pure water for TFC operation was successfully purchased and installed. Earlier purchased distilled water had poor quality and led to losses during TFC operation.

Finishing department. The repair of catheads has been completed, the issue with shot-blasting machine spill has been solved. Next points of the agenda are financing the repair of the second shot-blasting machine and installation of the third in sand-blending department.

Electromotors. Overhaul covered the repair of about 70% of electric motors: bearings, sealing elements were replaced in order to eliminate dust and fractions penetration and to prevent the electromotor combustion.

In addition to repair works on the manufacturing sectors, special attention was paid to improving the employees’ conditions. We started the implementation of a fundamentally new approach in the outfitting of locker rooms with separation into functional areas. Equipment was moved during the overhaul, so all the forces of mechanical repair division will be directed to the outfitting of new locker rooms for staff.

The operational experience and analysis of financial indicators for the idle hours cost make the benefits obvious. Thereby, overhaul is certainly a necessary process. According to the overhaul results we may talk about the main goal achievement – the prevention of emergencies, of increasing equipment depreciation and, consequently, the increase of efficiency. Suchwise, mechanical repair division already focused on planning the overhaul for the next year.