Boiler feed pumps (informally termed as mini turbine owing to its criticality) in thermal power plants are prone to normal wear and tear over a period of time, which leads to loss of pump efficiency and sometimes accidental failures resulting in heavy damages and prolonged shut downs. Re-engineering approach using High Performance Coatings by Plasma & HVOF processes, has recently enabled to add new world-class dimensions by reclamation & complete overhauling of Boiler Feed Pump Internal Cartridges (6“ LL Pacific Pumps Inc USA and 200 KHI, BHEL, India make), in order to obtain increased life cycle, maintain pump efficiency, De-accelerated wear rate. This was accomplished by establishing perfect interrelationship of cartridge assembly, providing exacting tolerances to meet functional and assembly requirement, and incorporating international standards for protective wear shielding by Plasma & HVOF technology on wear prone critical components. This paper describes the Re-engineering methodology adopted to improve the performance of the Boiler Feed Pump with the help of surface modification using plasma and HVOF coatings on critical components showing wear patterns, which led to the development of proprietary ceramic and cermets coatings after extensive laboratory and field trials. The Reengineered Boiler Feed Pumps are showing superior performance at one of the major power generating unit in Central India.

Shreenath has been engaged in the manufacturing and reclamation of engineering components by using the full range of thermal spraying since 1990. The analytical case studies of some of the tribological solutions provided to the core industries in Central India by HVOF spraying are presented in this paper. The case studies presented in this paper are the reclamation of the Vertical shaft of a bowl mill used for feeding crushed coal to the power plant, the engine spares of the earth moving machinery of the mining industries and the press rolls made up of chilled cast alloy steel, of defence industry. The surface characteristics needed for these applications, along with high hardness, bond strength and thermal conductivity could be achieved by the HVOF spraying using Topgun. In all the cases, the component life has been increased few folds and a direct cost saving of 30-70% was achieved. In addition, such an optimized reclamation reduces the down-time loss and improves the working efficiency.