Intructions components and maintenance edition5

INSTRUCTIONS FOR L GFCA ENGINES EDITION TYPE INSTRUCTIONS FOR L GFCA (CONSTANT PRESSURE) ENGINES The purpose of this book is to provide generol informotion ond mointenonce of a B&W 2-stroke, cross head engine obout the design, The contents have been prepared on the bosis of engine type L67GFCA, the book should not be taken to apply to any specific engine, therefore have inserted some alternative designs All references page No Example: to this book should include Instructions for L GFCA title, Type Engines, edition edition No., but we and possibly 5, page 901.02-02 This book is subject to copyright protection The book must not, either wholly or partly, be copied, reproduced, made public or in any other way made available to a third part without written consent to this effect from B&W Diesel A/S M.A.N.-B&W DIESEL A/S Stamholmen 161 • DK-2650 Hvidovre - Copenhagen • Denmark Cables: bwdiesel • Telex: 16573 bumei dk • Telephone: +45 492501 901.01 - 08 CYliNDER The cyli nder valve which bores for the hausings with provided for COVER cover is made of steel and has a central bore for the exhaust is attached by means of four studs The cover furthermore has twa fuel valves, which are resiliently mounted by means of spring disc springs under the nuts of the studs Other bores have been starting valve, starting air inlet, safety valve and indicator valve The lawer part of the cylinder cover has eight tangential, inter-connected cooling water bores which are closed from the outside by means of plug screws Cooling water is supplied through cooling water connections from the cooling jacket around the upper part of the cylinder liner to the tangential bores and is thence passed to an annul ar duct K at the periphery of the cover From duct K the water is passed through radial bores on the entire circumference of the cover to another annular duct H situated at the exhaust valve bore, and on through cooling water connections to the exhaust valve proper 901 02 - 02 HYDRAULIC RING FOR CYLINDER COVER The cylinder cover is tightened against the top of the cylinder liner by means of nuts and studs fitted in the cylinder block On top of the cylinder cover is located a steel ring incorporating a hydraulic tightening device for each of the cover attachment studs The cylinders of the tightening devices are arranged as bores in this ring, inter-connected through bored oil ducts Each cylinder is equipped with a ring-shaped piston and two sealing rings The cylinder cover nuts each consist of an inner nut fitted on the cover stud and bearing against the piston of the tightening device, and an outer ringshaped nut suiting the external thread of the inner nut The underside of the outer ring-shaped nut is spherical and bears against a corresponding spherical washer When tightening the cover, the inner nut, and thus the piston of the tightening device, is screwed up with the aid of a face spanner When hydraulic pressure is applied to the system, the piston of the tightening device is pressed upwards resulting in the cover stud being slightly lengthened, following which the outer ring-shaped nut can be screwed up with a tommy bar When the system is rei ieved of hydraul i c pressure, the tighteni ng pressure is transmitted to the outer nut, and on through the washer to the cyl inder cover Between two of the tightening devices at the manoeuvring side of the engine is fitted a snap-on coupling for connection of the hydraulic high-pressure pump Between the other devices there are bleed screws taht are to be opened when filling and venting the system The hydraulic ring is attached to the cylinder cover by means of four eye screws which are also used when lifting the cover The ring proper can be lifted by removing the eye screws and fitting some larger eye screws that fit an internal thread in the holes However, the ring is not usually to be separated from the cyl inder cover ... lifting the piston and, besides, the piston crown is provided with chromium-plated grooves for piston rings All the piston rings have oblique cuts - have right-hand, and have Ieft- hand cuts The piston... to the piston and rod and transrod Between piston crown and skirt, whi ch are assembled with a number of screws, there is a heavy clomping ring which presses the piston rod and the cooling element... ring-shaped piston and two sealing rings The cylinder cover nuts each consist of an inner nut fitted on the cover stud and bearing against the piston of the tightening device, and an outer ringshaped