Instructions for S26MC type engines componets and maintenance edition 2

Instructions for Main Engine Type S26MC The purpose of this book is to provide general information about the design and maintenance of B&W 2-stroke crosshead engines The contents have been prepared on the basis of a standard engine type S26MC, but the book should not be taken to apply to any specific plant All references to this book should include title, edition No., and possibly page No Example: Instructions for S26MC Type Engines, Edition 2, page 901.01-27 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 party without the written consent of this effect from MAN B&W Diesel NS MAN B&W Diesel A/S Stamholmen 161 DK-2650 Hvldovre Denmark Teleph.: +45 31 49 25 01 Telex : 16592 manbw dk Telefax: +4531 492066 901.01-27 CYllta:R COVER Plate 90101 The cylinder cover is made of steel and has a central bore for the exhaust valve, which is attached by means of four studs The cover furthermore has bores for the fuel valves Other bores have been provided for starting valve, starting air inlet, safety valve and indicator valve Cooling water is suppli ed through cooling water connections from the cooling jacket around the upper part of the cylinder liner to an annular duct at the periphery of the cover From this duct the water is passed through bores on the entire circumference of the cover to another annular duct which is situated at the exhaust valve bore, and on through cooling water connections to the exhaust valve proper The cylinder cover is tightened against the top of the cylinder liner by means of nuts and studs fitted on the frame box The studs are tightened by means of hydraulic jacks 12 RETIGHTENING (F 912-3 STAY BOlTS Edition 29 Page (2) Before retightening the stay bolts, remove the protective caps Clesn the contact faces and mount the hydraulic tool on s psir of atsy bolts positioned oppoaite each other on the middle of the engine Place the two extension studs, one on esch stud, mount the spacer rings around these studs with the slots opposite the nuts and, finally, mount the double set hydraulic jacks on the studs Connect the high-pressure pump to the distributer block with a hose and with four hoses from the distributor block to the hydraulic jacks, so that the two stay bolts are tightened in one operation Start the retightening of the stay bolts and proceed to tighten the stay bolts in pairs, working from the middle toward one end of the engine and then from the middle again toward the other end 912-3 RETIGHTENING Edition 29 Page (2) STAY BOlTS (F Maintain the hydraulic pressure at the value indicated in D-1, and retighten the stay bolt nuts with a tommy bar Before relieving the system of pressure, check with a feeler gauge that the nuts bear against the contact face Reconnect the hydraulic tools to the pair of stay bolts first tightened Tighten to 10% below D-1 and check if the nut is loose If the nut is not loose: Tighten the stay bolts to D-1 If the nut is loose: Tighten all stay bolts once again to D-1 After completing the retightening procedure, mount the protective caps The stay bolts are mounted in such a way that, when the uppermost stay bolt nut is loosened, there is a clearance, as stated in D-2, between the contact face of the lowermost nut and the bedplate APPlICATION 913-1 Edition 12 Of HYDRAILIC TOILS Page (2) A B C D E F G H Snap-on coupling Tool attachment thread Bleed screw Piston Cylinder Sealing rings Spacer ring Tommy bar Nut J K S U Stud or bolt Extension stud Clearance Milled recess for feeler gauge Studs or bolts provided with thread for attaching hydraulic tools and with circular nuts must be loosened and tightened-up only by means of the hydraulic tools supplied The hydraulic tools for the crosshead bearing consist of a jack with internal thread to suit the tool attachment thread on the stud or bolt, and a spacer ring which is to be placed under the jack and around the nut that is to be loosened or tightened For the cylinder cover, also an extension stud is added to the tools For the staybolts, crankpin bearings and main bearings both an extension stud and an extra lower hydraulic jack are added to each set Each part is marked with a sign showing where to use· the specific part The jack(s) is/are connected, via a distributor block, to a high-pressure pump, which is set to deliver hydraulic oil at the pressure indicated on the jack(s) and on the data sheet in the relevant section of this instruction book The stud or bolt concerned is thereby lengthened relative to the oil pressure applied and the piston area, and the nut can be loosened or tightened, as required, with the aid of a tommy bar The jacks must never be overloaded or exposed to blows or impacts They are marked with a "Max lift", which must not be exceeded APPLICATION Of 913-1 HYDRAUlIC TOOlS Edition 913-1.1 12 Page (2) The upper hydraulic jacks are so designed that the pressure is relieved of the pressure chamber in the event thst the "Max li ft" limit is exceeded, and the oil will be pressed out into the space between the stud and the spacer ring Whenthe pressure is relieved in this way, the lowermost sealing ring will in most cases be damaged Therefore inspect and, if necessary, replace this sealing ring The oil used must be pure hydraulic oil or turbine oil (with a viscosity of about SAE 20) Oils such as, for instance, lubricating oil (system oil) or cylinder lubricating oil must NOTbe used, as these oils are normally alkaline and can thus damage the back-up rings The following instructions must be closely followed to prevent accidents or damage, and after use the jacks should be cleaned and kept in the wooden boxes supplied NOTE: WHEN USINGHYDRAULIC TOOLS,EYE PROTECTORS ANDGLOVESMUSTBE USED MAINTENANCE Disassembling the piston and cylinder is best carried out by taking out one of the bleed screws and pressing the parts from each other by means of compressed air After disassembling, check that there are no damage marks on the sliding surfaces of the parts If metal particles are present, they will damage the sealing and back-up rings Keep the sliding surfaces and threads coated with acid-free grease or molybdenum disulphide The hydraulic nuts not require any maintenance other than replacement of defective aealing rings These consist of an O-ring and a back-up ring, which are positioned in ring grooves in the piston and cylinder Edition APPLICATION Of 12 Page (4) Single HYDRAUlIC TOOlSLOOSENItI;Of tilT Hydraulic Jack Carefully clean the tool attachment thread on the crosshead bearing bolt, the nut and the surrounding parts Grease the tool attachment thread with molybdenum disulphide or with graphite and oil On the cylinder cover stud, also mount the extension stud on the tool attachment thread Place the spacer ring around the nut in such a posi tion that the tommy bar can be applied through the slots when the nut is to be loosened Screw the jack on to the tool attachment thread of the bolt/ stud, until the cylinder of the jack bears firmly against the spacer ring, and check that the parts are guided correctly together By means of a hose, connect the jack to the distributor block and connect the block to the highpressure pump by another hose Loosen the bleed screw and fill the system with oil until oil, without bubbles, flows out of the bleed screw, which is then tightened again Adjust the clearance between the piston and cylinder of the jack (see the sketch and table) to provide for contraction of the bolt/ stud If the clearance is too large, adj ustment is made by loosening the bleed screw The clearance is to have relation to the "Max lift" of the jack and has the purpose of making it possible to dismount the jack after loosening the nut After adjustment, check again that there is no clearance between the cylinder/spacer ring/surface APPLICATION Of 913-1.1 HYDRAUlIC TOOlS - Edition LOOSENIN; Of NJT 12 Page (4) Increase the oil pressure to the prescribed value If the rut does not come loose, the pressure may be raised by approx 90 bar Unscrew the rut with the tommy bar, making sure that the nut is not screwed up against the jack Relieve the system of pressure, disconnect the high-pressure pump, and remove the hydraulic tools 913-1.1 Edition 12 Page (4) APPLICATION Of HYDRAUlIC TOOlS LOOSENIN; Of NJT Double Hydraulic Jack Carefully clean the tool attachment thread, on ei ther the staybolt, crankpin bearing stud or main bearing stud, the nut and the surrounding parts Grease the tool attachment thread with molybdenum disulphide or with graphite and oil Mount the extension stud on the tool attachment thread of the bolt/stud Place the spacer ring over the extension stud around the nut in such a position that the tommybar can be applied through the slots for the purpose of tightening the nut Mount the lower hydraulic over the extension stud and it on the spacer ring Make that the cylinder of the jack the spacer ring are guided rectly together jack land sure and cor- Screw on the upper hydraulic jack to the thread of the extension stud until the cylinder of the upper jack bears firmly against the cylinder of the lower jack B By means of hoses connect both the upper and lower hydraulic jack to the distributor block and connect the block to the high-pressure pump by another hose Loosen the bleed screws both in the upper and the lower jack, fill up the system with oil until oil, without bubbles, flows out of the bleed screws Then tighten the bleed screws again Adjust the clearance between the piston and the cylinder of the upper jack (see the sketch and table) to prov ide for contraction of the bolt/stud If the clearance is too large, adjustment is made by loosening the bleed screw in the upper jack After adjustment, check once more that there is no clearance between the cylinders/ spacer ring and surface The clearance is to have relation to the "Max lift" of the jack and has the purpose of making it possible to dismount the jack after loosening the nut 365 APPLICATION IT HYDRAUlIC TOOLS LOOSENIJ«; IT NJT 913-1 Edition 913-1.2 12 Page (4) Increase the oil pressure to the prescribed value If the nut does not come loose, the pressure may be raised by approx 90 bar 10 Unscrew the nut with the tommy bar, making sure that the nut is not screwed up against the extension stud 11 Relieve the system of pressure, disconnect the high-pressure pump, and remove the hydraulic tools Edition 12 Page (4) Single APPLICATION IT HYDRAULIC TOOLS TIGHTENIJ«; IT NJT Hydraulic Jack Thoroughly clean the nut, the thread of the crosshead bearing bol t, the contact faces, and surrounding parts Clean and lubricate the main and tool attachment threads and the thread in the nut with molybdenum disulphide or with graphite and oil Fit the round nut on the thread and tighten it with the tommybar Check with a feeler gauge that the contact face of the nut bears on the entire circumference On the cylinder cover stud, also mount the extension stud on the tool attachment thread Place the spacer ring around the nut in such a position that the tommy bar can be applied through the slot for the purpose of tightening the nut Press the piston and the cylinder of the jack firmly together Screw the hydraulic jack on to the tool attachment thread Make sure that the cylinder of the jack bears firmly against the spacer ring and that the parts are guided correctly together By means of a hose, connect the jack to the distributor block and connect the block to the highpressure pump by another hose loosen the bleed screw and fill the system with oil until oil, without bubbles, flows out of the bleed screw, which is then tightened again OF 913-1.2 HYDRAll.IC TOOlS - Edition TIGHTENI, OF NIT APPLICATION 913-1.2 12 Page (4) Increase the oil pressure to the prescribed value, and tighten the nut by means of the tommy bar applied through the slots of the spacer ring While maintaining the pressure, check with a feeler gauge introduced through the recess at the bottom of the spacer ring that the nut bears against the contact face Relieve the system of pressure, disconnect the pump, and remove the hydraulic tools When new studs/bolts and nuts are tightened for the first time, the jack is not to be removed, but loosen the nut as descr ibed under "Loosening" , points 3-4-5, and then tighten the nut again according to the procedure under "Tightening", points 3-4-5 Edition APPLICATION 12 Page (4) OF HYDRAULIC TOOlS TIGHTENING OF NIT Double Hydraulic Jack Thoroughly clean the nut, the thread on either the staybolt, crankpin bearing stud or main bearing stud, the contact faces, and surrounding parts Clean and lubricate the main and tool attachment threads and the thread in the nut with molybdenum disulphide or with graphite and oil Fit the round nut on the thread and tighten it with the tommybar Check with a feeler gauge that the contact face of the nut bears on the entire circumference Mount the extension stud on the tool attachment thread of the bolt/stud Place the spacer ring over the extension stud around the nut in such a position that the tommybar can be applied through the slot for the purpose of tightening the nut S Press the piston and the cylinder of both the upper and the lower hydraulic jack firmly together Mount the lower jack over the extension stud -and land it on the spacer ring Make sure that the cylinder of the jack and the spacer ring are guided correctly together Screw the upper jack on to the thread of the extension stud until the cylinder of the upper jack bears firml y against the cylinder of the lower jack By means of hoses connect both the upper and the lower hydraulic jack to the distributor block and connect the block to the high-pressure pump by another hose Loosen the bleed screws in both the upper and the lower jack, fill up the system with oil until oil, without bubbles, flows out of the bleed screws Then tighten the bleed screws again 369 APPLICATION HYDRAUlIC TlGHTENI, IF TOOlS IF ••.• T 913-1.2 Edition 12 Page (4) 10 Increase the oil pressure to prescribed value, and tighten nut by means of the tommy applied through the slots of spacer ring the the bar the 913-1.3 Edition 12 HYDRAUlIC TOOlS- Page (1) OF OOLT TIGHTENI, SUBSEQUENT CHECKI, Mark off the position of the nut in relation to its contact face Fit the hydraulic tools as described under loosening, points 1-2 11 While maintaining the presaure, check with a feeler gauge introduced through the recess at the bottom of the spacer ring that the nut bears against the contact face 12 Relieve the system of pressure, disconnect the pump, and remove the hydraulic tools 13 When new studs/bolts and nuts are tightened for the first time, the jack is not to be removed, but loosen the nut as described under "Loosening", points 9-10-11, and then tighten the nut again according to the procedure under "Tightening", points 10-11-12 Increase the oil pressure slowly towards the prescribed value while trying continuously with the tommy bar to loosen the nut Note down the oil pressure indicated by the pressure gauge when the nut comes loose Pump until reaching the correct tightening pressure, and retighten the nut, if required Relieve the system of pressure, disconnect the high-pressure pump, and remove the hydraulic tools Note down the angular displacement, if any, of the nut, or measure and note down the distance "x" between the mark on the contact face and that on the nut HYDRAUlIC TOOlS- 913-1.4 MAINTENANCE Edition 913-1.4 12 Page (2) The upper and lower hydraulic jacks require no maintenance except replacement of defective sealing rings, each of which consists of an O-ring and a back-up ring fitted in ring grooves in the piston and cylinder The piston and cylinder are separated by taking out the screw and pressing the parts with the help of compressed easily bleed apart air Make sure that there are no marks or scratches on the sliding surfaces of the parts The presence of metal particles will damage the sealing rings The piston and cylinder of the lower jack are to be separated in the same easy way as described for the upper jack Edition HYDRAUlIC TOOlS12 MAINTENANCE Page (2) When changing the sealing rings, first mount the back-up ring and then the O-ring Be aware that the back-up ring must be away from the pressure cham-b-e-r-and the O-ring close to the pressure chamber See on the sketch the correct mounting of both the upper and the lower sealing rings The same principle applies to both the upper and the lower jack After fitting the complete sealing rings, the piston and cylinder are pressed together by means of the tool supplied See that the rings not get stuck between the piston and cylinder 913-5 Edition TIGHTENING 03 WITH TORQUE SPANNER Page (1) Before acrewing the nut a on, the threads and the contact faces ahould be greased with a mixture of graphite and oil or molybdenum disulphide with a friction coefficient ~ = 0.1 _ 0.12 (e.g MOLYKOTE paste type G) The nuts should fit easily on the thread, and it should be checked that they bear on the entire contact face In the case of new nuts and studs, the nuts are to be tightened and loosened two or three times in order that the thread may assume its de finite shape; thus obviating the risk of loose nuts The torque spanner for torques higher on it, and it must hammering on it or Rah801 torque must not be used than those stamped not be damaged by the like 8p8lVler The handle of the torque spanner is provided with a scale indicating the torques at which the spanner can be set For setting the spanner at the required torque, there is a ball on a small arm at the end of the handle By pulling the ball with the arm outwards, a small crank handle is formed A spring-loaded slide in the handle is provided with a mark which, when turning the crank handle, can be set at the required torque on the scale The functioning of the torque spanner is as follows: The above-mentioned spring acts on a pawl system in the handle, and when using the spanner, this pawl system will be released when the pre-set torque has been reached, at which moment a small jerk is felt in the spanner and a small click is heard 374 913-7 Edition 02 Page (1) lOCKING Of SCREWS AND NUTS All acrewed and bolted connections inside the engine, as well as all movable joints are secured against untimely loosening by means of different types of locking devices When reassembling the engine after overhauls, it is vital that all such screws and nuts are again locked correctly lock washers, tab washers, locking plates, etc., must always be replaced The tab-like projections, etc., on the washers are to be bent back over one of the flats of the screw or nut concerned Used spring washers must be replaced Sel f-locking nuts must be replaced; they may only be used once locking wire: Always fit new wire after tightening-up the screws The locking wire is to be mounted in such a way that both parts are tightened when the screw is turned left .. .Instructions for Main Engine Type S26MC The purpose of this book is to provide general information about the design and maintenance of B&W 2- stroke crosshead engines The contents... should include title, edition No., and possibly page No Example: Instructions for S26MC Type Engines, Edition 2, page 901.01 -27 This book is subject to copyright protection The book must not, either... surface of the sealing and scraper ring segments ensures that the rings will bear agains t the piston rod even in worn condition 38 42 MOUNTING OF PISTON 9 02- 2 .2 9 02- 2.3 Edi tion Edition 50 Page (3)