This picture shows the Plastigage strip on #1 and #2 main journals. Our calculations on bearing thickness were right on the money, and as you can see, the plasti-gauge clearly shows that we have .0015" clearance.
FLAME ARRESTORS AND SHIELDING The intention of the requirement to shield the valve discharge was to reduce the possible danger to personnel from flame emission. However explosion testing has shown that whilst a flame arrestor will work satisfactorily when shielding is not fitted, when shielding is fitted, the energy from the discharge is focussed in one direction, and there will be an emission of flames during an explosion. The fitting of shielding also reduces the effective outflow area of a valve. Since July 2002 it has been a Lloyds Register rule requirement to fit flame arrestors and to test the relief valve with any proposed shielding to be fitted to the valve when installed on the engine. A test procedure for new crankcase relief valves has been developed over the past four years by MAN B&W, The Physical Test Institute in the Czech Republic , Hoerbiger, and various classification socie...
There are two methods of oil mist detection, Obscuration and Light Scatter . The earlier forms of oil mist detector used an obscuration type detector, the most well known type being the early Graviners. Schaller use obscuration in their Visatron range of OMDs. Light scatter is a modern method of oil mist detection used by QMI and the Latest Graviner Mk6 OBSCURATION The older type of obscuration type of detector consists of two parallel tubes of equal size, each having a photoelectric cell at one end which generates an electric current directly proportional to the intensity of the light falling on its surface. Lenses are fitted to seal the ends of each tube but allow light to pass. Two identical beams of light from a common lamp are reflected by mirrors to pass along the tubes onto the cells which are then in electrical balance. The samples drawn from the crankcase are drawn in turn along the m...
REGULATIONS The provision of crankcase explosion relief valves for marine diesel engines is an international safety requirement stemming from two sources, IMO SOLAS Chapter II-1 and IACS Unified Requirements M9 and M10. Summarising, the requirements that relate to explosion relief valves are: i. Crankcases for engines having a cylinder bore greater than 200mm and above or having a crankcase gross volume exceeding 0.6m 3 are to be provided with explosion relief valves. ii. Crankcases for engines having a cylinder bore not exceeding 250mm are to be provided with at least one explosion relief valve at each end of the engine. If an engine has more than eight crank throws an additional valve is be fitted at the middle of the engine. iii. Crankcases for engines having a cylinder bore greater than 250mm but not exceeding 300mm are required to have at least one crankcase explosion relief valve at each alternate crankthrow ...
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