Index

Page 1 (1)

The contents of these spare part plates with tools are a summary of STANDARD TOOLS for normal maintenance and EXTRA TOOLS for reconditioning, which can be supplied by MAN B&W Diesel A/S, Holeby. Thus, the list comprises the total extent of tools available for this engine type.

For each specific plant the amount of tools delivered depends of the contractual specifications.

The tools listed are assembled in sections corresponding to the chapters of the instruction book.

However, some tools such as torque spanners, hydraulic tools etc. may also have other applications. Information about the exact use of the tools appears from the relevant sections in the instruction book.

Note: The table on the spare part plates is marked with an S or an E. An S means that the tools are supplied when ordering Standard tools and an E means that the tools are supplied when ordering Extra tools, i.e. Tools for Reconditioning (extra tools are not standard delivery)

08028-0D/H5250/94.08.12

L23/30H

Description:

Application of hydraulic tools loosening of nut,

tightening of nut and subsequent checking of bolt Hand tools: tightening.

Copaslip or similar.

Starting position:

Related procedure:

Nuts on studs or bolts provided with draw thread for hydraulic tools must be loosened and tightened up only by means of the hydraulic tools supplied.

A

B C

D

E S

F

G

H

U

I

Fig 1.

The hydraulic tools 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 which is to be loosened or tightened.

The jack is connected to a high-pressure pump, which is set to deliver hydraulic oil at the pressure indicated on the jack and on the data sheet in the relevant section of this instruction book.

The stud or bolt in question is thereby lengthened relatively to the oil pressure applied and the piston area, and the nut can be loosened or tightened, as required, by means 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.

The hydraulic jacks are so designed that the pressure is relieved at the bottom of the pressure chamber in the event that the "max. lift" limit is exceeded, and the oil will be pressed out into the space between the stud and the spacer ring.

When the pressure is relieved in this way, the lowermost sealing ring will be damaged in most cases. 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 NOT be 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 using hydraulic tools, eye protectors and gloves must be used.

Loosening of Nuts

1) Carefully clean the tool attachment thread, the nut and the surrounding parts.

Grease the tools attachment thread with copaslip or similar.

Place the spacer ring around the nut, so that the tommy bar can be applied through the slot when the nut is to be loosened, see fig 2.

2) Screw the jack on the tool attachment thread and adjust the clearance between the piston and the cylinder to provide for contraction of the bolt/stud. The clearance is to have relation to the "max. lift" of the jack in accordance with the table shown, see fig 3.

Make sure that the cylinder bears firmly against the

08028-0D/H5250/94.08.12

08028-0D/H5250/94.08.12

Fig 2.

spacer ring and that these parts are guided correctly together.

Connect the snap-on coupling of high-pressure pump to the jack, loosen the bleed screw, and fill up the system until oil, without bubbles, flows out of the bleed screw, which is then tightened again, see fig 4.

3)Increase the oil pressure to the prescribed value. If the nut does not come loose, the pressure may be raised by approx. 50 bar, however never more than 10% in excess of the stated tightening pressure.

4)Unscrew the nut with the tommy bar, making sure that the nut is not screwed up against the jack, see fig 5.

5)Relieve the system of pressure, disconnect the high-pressure pump, and remove the hydraulic tools, see fig 6.

Tightening of Nut

1) Thoroughly clean the nut, the main thread, the tool attachment thread, the penn securing, if fitted, the contact faces and surrounding parts.

Make sure that the nut fits easily on the thread, and lubricate the main and tool attachment threads and

Fig 3.

Fig 4.

08028-0D/H5250/94.08.12

08028-0D/H5250/94.08.12

Fig 9.

the nut as described under "loosening", items 3-4-5, and then tighten the nut again according to the procedure under "tightening", items 3-4-5.

Subsequent Checking of Bolt Tightening

3)Increase the oil pressure slowly towards the prescribed value while trying continuously with tommy bar to loosen the nut. Note down the oil pressure indicated by the pressure gauge when the nut comes loose, see fig 12.

4)Pump until reaching the correct tightening pressure, and retighten the nut, if required.

5)Relieve the system of pressure, disconnect the high-pressure pump, and remove the hydraulic tools.

Fig 11.

Fig12.

and space rings are not available, a nut can be loosened with the jack according to the following procedure:

1) Screw the snap-on coupling part off the jack and fit in its place a grease nipple suiting the hose of a high-pressure grease pump.

Fill up the jack with high-pressure grease instead of lubricating oil.

Heavy grease

08028-0D/H5250/94.08.12