Marine Log - August 2007 - (Page 47A) Technews Tool for rebuilding cylinder inside diameters After installation in the field, valves and pumps often require maintenance to rid the inside diameter (ID’s) of foreign material including rust, corrosion, accumulated chemicals, and biological matter. Improper cleaning and resurfacing of the ID’s of those bores can mean fewer operating hours between servicing as well as degraded performance. Brush Research Manufacturing Company (BRM), Los Angeles, Calif., offers a line of flexible ball-style hones that are well suited for heavy-duty cleaning and resurfacing applications. This tool is characterized by abrasive globules that are permanently mounted to flexible filaments that are attached to a center shaft. This tool can be used virtually anywhere for sophisticated surfacing, de-burring, edge-blending, cleaning and rebuilding of cylinder ID’s. In order to extend their service lives, big bore engines used in large ocean going ships must have their cylinder liner walls deglazed, refinished and crosshatched during overhaul to remove corrosion or the formation of clay, wax or other solids may prevent proper valve operation or block lubricants. BRM’s Flex-Hones produce a controlled surface condition unobtainable by any other method. The tool can de-burr, clean out passages, and provide ID’s with a super-smooth plateau finish free of cut, torn and folded metal. “The unique design of the Flex-Hone allows it to pass over the ports, smoothing down all the rough spots,” explains Clarence Mayers, coordinator for Diesel Supply Company. “The firing pressure in the combustion chamber causes the rings to load from the back side pushing out against the cylinder wall. Flex-Hones are available in sizes up to 50 inchThis style of es in diameter hone smoothes out all of the rough spots around the ports or any other part of the cylinder liner walls, top to bottom.” Whether used for cleaning, de-burring or plateau finishing, the tool provides a low-temperature abrading process that exposes the undisturbed base metal designed to produce a long wearing surface free of fragmented, amorphous or smeared metal from previous operations. The abrasive globules each have independent suspension that is self-centering, self-aligning to the bore, and self-compensating for wear. New mixed-flow impeller design from MJP Waterjets Swedish propulsion specialists MJP Waterjets recently introduced a new version of its mixed-flow impeller and pump design with Computational Fluid Dynamic (CFD) optimized inlets. The heavy duty stainless steel MJP waterjets are said to be more resistant to wear and corrosion and ensure a long service life. By utilizing a strong hub unit bearing design, the impeller is kept in a firm position within the pump, ensuring that the tip clearance is maintained at a minimum level throughout its service life. In addition, the new MJP bearing arrangement also simplifies maintenance and service work because the entire hub unit can be accessed from aft. New features such as the floating and flexible drive shaft simplify installation, and the absence of underwater appendages reduces hull resistance and allows for shallow draft operation. Chloropac systems for LNG carriers Korea’s Samsung Heavy Industries (SHI) has awarded Siemens Water Technologies an order for 14 Electrocatalytic Chloropac sodium hypochlorite-generating systems for installation in liquefied natural gas (LNG) carriers for three petrochemical companies. The Chloropac systems from Siemens will help prevent marine growth in the main components of the LNG carriers’ seawater cooling systems, including sea chests, piping, coolers, and heat exchangers. The first system was delivered to SHI in May, with subsequent deliveries scheduled throughout 2007 and 2008. Vessel capacities range from 155,000 m3 to 266,000 m3. The Chloropac systems were specified for their ability to treat varying seawater flowrates of 2,800 m3/h to 5,000 m3/h, with continuous sodium hypochlorite dosing levels of 0.2 ppm to 0.5 ppm. Electrocatalytic Chloropac systems cost-effectively control micro-fouling organisms (slime, algae, and seaweed) as well as macro-fouling organisms (barnacles, mussels, clams, and hydroids). By passing electric current through the seawater, Chloropac systems convert sodium chloride into sodium hypochlorite, the active ingredient required for disinfection, water sterilization and organic fouling prevention. 47A MARINE LOG AUGUST 2007 www.marinelog.com http://www.marinelog.com
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