repair boiler sms 3 0001 0044 2a

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REPAIR INSTRUCTIONS ITEM BO 001 / EE 001

This document consists of 10 page(s)

SAACKE MARINE SYSTEMS Suedweststrasse 13, 28237 Bremen, GERMANYTel.:+49 421 6495 138, Fax.:+49 421 6495 363, email: [email protected]

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Doku-Nr.: SMS 3-0001-0044/a/2

Issued on: 04.12.2006Issued by: 1100/Fre

MARINE SMOKE TUBE BOILER/ECONOMIZER

Instructions for repair and refitting of damaged smoketubes


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Contents:

0 General customer information 3

1 Repair technology 3

2 Preparation of hot work in exhaust gas con-taminated area

4

3 Sealing of single smoke tubes 5

4 Replacement of single smoke tubes 7


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0.) GENERAL CUSTOMER INFORMATION

Safety related information are indicated by pictograms as follows:

Warning!

Ignoring safety information can endanger life or result in serious injury!

Caution!

Ignoring safety information can result in injury to persons or damage tomachinery or other materials!

Take care!

Ignoring safety information can result in damage to machinery or other ma-terials!

1.) REPAIR TECHNOLOGY

Take care !

All work to be undertaken on the pressure part of the boiler body has to bechecked and approved by the classification society involved prior to start-ing the intended work scope. For this purpose, each time work on thepressure part of the boiler becomes necessary, a detailed repair procedure

has to be issued and provided to the classification society well in advanceof the scheduled work period.

The repair technology which is to be provided to classification society prior tostarting the intended work scope has to contain the following information:

- All necessary steps for preparing the welding according to the proceduresused and approved during newbuilding of the boiler. For these procedures,please refer to the approved original newbuilding drawing and the detailstherein.

- The intended welding mode (e.g. WIG) for each part of the welding seam (rootrun, middle run, final run) has to be specified in detail. Welding mode to becarefully chosen with regard to the type of damage, equipment on board andcapabilities of the repair personnel.

- All welders who will be involved in welding the repair seams have to be certi-fied welders with valid certificates. All welders and belonging certificates are tobe listed in detail.

- The intended testing procedure for each part of the welding seam has to bediscussed and agreed on with involved classification society in advance andhas to be specified in detail.


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- It has to be specified in detail how and when the pressure test after comple-tion of repair work shall be executed depending on local situation and time

schedule.

In any case has the repair work to be performed exactly according to the onceapproved repair technology. A deviation from that technology must be avoidedunless agreed on with involved classification society representative or local sur-veyor.

After completion of the repair work, the examination and approval of the repairscope will be performed by the local surveyor.If it should not be possible for any reason to have the repair scope examined,tested and approved right after completion, it might be agreed with involved clas-sification society that the CE of the vessel might inspect and preliminary approve

the proper execution of all repairs and that an authorized surveyor will attend thevessel soonest possible for final approval of the executed repairs.

In any case the decisions and directions of the involved classification society willtake priority over preliminary decisions and approvals.

2.) PREPARATION OF HOT WORK IN EXHAUST GAS CONTAMINATED AREA

Warning!

All hot work to be executed on ocean vessels in port have to be carefully

planned in accordance with local authority requirements and restrictions.Only qualified personnel which is fully capable of the intended type of hotwork is to be assigned.

If any hot work like welding, grinding or cutting shall be executed on exhaust gascontaminated surfaces in exhaust gas or composite boilers, the following prepara-tion steps have to be followed to ensure that any potential harm to the persons in-volved will be minimised as far as possible:

- The water space of the boiler is to be completely drained prior to any hot workon the boiler.

- The funnel draught is to be minimized by closing the exhaust gas duct behindthe repair zone to avoid that blistering sparks will be drawn into the silencer orfunnel.

- All contaminated surface which will be involved in cutting or welding shall becleaned thoroughly prior to start of work to avoid generation of hazardous va-nadine pentoxide.

- Cutting should be executed by cut-off grinder. To assist in handling of the cut-ting tool, a guidance collar from plate steel should be fixed by tack-weldingaround the tube or on top of the plate which is to be cut.

- Sufficient supply of fresh air to the repair site is to be ensured at any time.


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3.) SEALING OF SINGLE SMOKE TUBES

The total number of plugged tubes should not exceed 5% of the total heat transfersurface. If it becomes necessary to exceed this amount of plugged tubes, the de-fective tubes must be replaced according to the procedure described in chapter 4.To seal the damaged smoke tubes, please use the tube plugs which were deliv-ered in the spare parts scope at delivery of the boiler to shipyard. These plugs arespecially made to fit the smoke tubes of the boiler.To seal damaged boiler tubes, please proceed as follows. Basic requirement forall repairs is that the boiler is completely drained and cooled down to an extentwhich allows entering the exhaust gas and steam space without danger:

1 The manholes of the exhaust gas chambers are to be opened and the ex-haust gas inlet connection from main engine to boiler is to be sealed in order

that no sparks or debris might enter the turbocharger assembly. The drainand blow down connections are to be covered.

2 - The exhaust gas inlet and outlet chambers are to be thoroughly cleaned be-fore starting any hot work.

3 - The tube which shall be sealed is to be grinded on the surface in order toobtain a metallic bright surface for welding.

4 - After grinding, the actual inner diameter of the tube is to be checked as thetube might have been widened during mounting and grinding

5 - The tube plugs are to be reworked according to the actual tube end dimen-sions and are to be prepared for welding carefully in a tulip shape:

Prepare welding according to the information and dimensions (smoke tubediameter) T (plug length), t (tube plate thickness), t1 (welding seam depth), R(seam bottom contour), n (welding seam width) as given in the classificationapproved newbuilding drawing.


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6 - Prior to placing the plug into the tube, it is essential that holes of diameter >10 mm will be drilled or cut into the tube (one on top, one on bottom) just out

of the length which will be filled by the plug.

These circulation holes will ensure that the water might circulate inside thetube once the boiler is filled again and that the tube plug will be sufficientlycooled by the boiler water during operation later on.

7 - Special care has to be taken when preparing plugs for placing into the revers-ing chamber of the oil fired section of the boiler. The temperature to which theplugs will be exposed might be up to 1000 C locall y. The plugs which are to

be placed on the reversing chamber side of the tube shall be shortened to alength of max. t1 + 5 mm to ensure sufficient cooling of the plug material dur-ing burner operation.

8 - The tube plugs have to be placed in a tight fit into the tubes. For this purposewe recommend to tack-weld a short round bar onto the plug which can beused as mandrel. After placing and aligning the plug and after welding of theroot run, the round bar can be cut off again.

9 - After completion of each run (root run, middle run and final run), it is to bechecked according to approved repair technology.

10 - After completion of repair, remove all debris from the water drum and fromthe exhaust gas chambers, uncover the drain and blow down connections,manhole and headhole covers are to be closed and all sealings and gasketsthereon have to be replaced by new ones out of the spare parts stock.

11 - The boiler has to undergo a pressure test according to approved repair tech-nology.

12 - All repair steps have to be done exactly according to the approved repairtechnology. Additional requirements of the attending surveyor, which mightcome up during the repair procedure, have to be followed.


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4.) REPLACEMENT OF SINGLE SMOKE TUBES

If the total number of plugged tubes inside the boiler exceeds 5 % of the totalheating surface, it is not allowed to seal more tubes. Any additional defective tubemust be replaced by a new one to maintain the boiler capacity.Basically, all smoke tubes which have to be replaced have to be removed fromthe boiler by drawing out of the front (operators) side of the boiler on which theexhaust gas inlet chamber and burner are mounted.

To allow drawing smoke tubes out of the boiler front side, sufficient mountingspace has to be provided by surrounding construction according to below givendimensions (example shows composite boiler):

LB

l

L1

L1

= Boiler body diameter - see approved original drawingLB = Boiler body length - see approved original drawingl = Lifting lugs distance - see approved original drawing

L1 = Mounting space for tube retracting = LB + 100 mm

Given dimensions are for (partly) dismantled inlet chambers. To find outtotal mounting space, add inlet chamber depth from assembly drawing.


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Depending on actual position of damaged smoke tubes and on the actual engineroom space situation, it might become necessary to dismount a part of the ex-

haust gas duct before and aft of the exhaust gas boiler part.

For single tubes, hovewer, a small opening can be cut into the exhaust gas inletchamber to allow the defective tube to be drawn out without dismantling too muchof the surrounding system.

To exchange damaged boiler tubes, please proceed as follows. Basic require-ment for all repairs is that the boiler is completely drained and cooled down to anextent which allows entering the exhaust gas and steam space without danger:

1 The manholes of the exhaust gas chambers are to be opened and the ex-haust gas inlet connection from main engine to boiler is to be sealed in order

that no sparks or debris might enter the turbocharger assembly. The drainand blow down connections are to be covered.

2 - The exhaust gas inlet and outlet chambers are to be thoroughly cleaned be-fore starting any hot work.

3 - If the tube which has to be replaced was plug-sealed before, remove the tubeplug with a cutting torch.

4 - Cut the tube on the rear side behind the expanded part inside of the waterspace so that the tube may easily be taken out of the front plate. For this pur-pose, reach inside the tube with a cutting torch from the exhaust gas outletchamber. Tack weld a short angled steel bar to the short tube part to preventit from falling into the water space once the welding seam is removed. Nowgrind out the existing welding seam on the rear tube plate. After the weldingseam has been removed, cut the pipe end in length to take out the strengthand then pull it out of the hole with the attached angled bar. Anneal with cut-ting torch to take the strength from the material if necessary.

Take care!

When grinding out the existing welding seams, take special care forthe fact that the grinding must not take material from the tube plateso that the tulip shaped welding seam preparation can be executed

trouble-free according to approved repair technology!

5 - Cut the pipe end carefully in length over the expanded area to take thestrength out of the material so that it may be compressed during taking out ofthe tube.Tack weld another angled steel bar to this part of the pipe.Nowgrind out the existing welding seam on the front tube plate.

Take care!

When grinding out the existing welding seams, take special care forthe fact that the grinding must leave enough material on the tubeplate so that tulip shaped welding seam preparation can be exe-cuted according to approved repair technology!


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6 - Remove the existing smoke tube by pushing it from the rear side of the boilerwith a special steel mandrel and by pulling it simultaneously on the angled

bar on the front end. Assist if necessary by annealing the tube carefully with acutting torch. The mandrel has to be manufactured on board according to theactual smoke tube dimensions.

7 - Prepare the holes in the front and rear tube plates and in the internal revers-ing chamber cover plate. The holes have to be grinded and polished to metal-lic bright condition to ensure optimum welding conditions.

The welding seam has to be prepared basically according to approved repairtechnology as shown in below sketch:

Prepare welding exactly according to the information and dimensions (smoke tube diameter), t (tube plate thickness), t1 (welding seam depth), R(seam bottom contour), n (welding seam width) as given in the classificationapproved newbuilding drawing.

8 - Remove grinding dust and debris vacuum cleaner as far as the water spaceis accessible through the holes of the removed tubes.

9 - Check the actually required tube length before cutting the new tube to size asdeviations between design drawing and actual length may occur from time to

time.

10 - To insert the new tubes into the prepared holes please follow step by step:

- Prior to insertion, the tubes have to be tested for their ability to be expandedinto the holes of the tube plates. This test has to be performed in a separatehole of the same size. It might become necessary to perform local heattreatment on the tubes to ensure optimum expansion ability. In any case,the tube end are to be grinded and polished to metallic bright condition toensure best welding conditions.


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- Insert the new tubes via the front tube plate. To assist in placing the tubeseasily into the hole on the rear tube plate, stick a round bar of adequatelength into the rear tube plate hole and lead the new tube into position bythe aid of that bar.

- Alignment of the tube between both tube plates has to be done in order thatthe projecting end at both tube plates are nearly of the same length.

Take care!

When aligning the smoke tubes between front tube plate and re-version chamber front plate, make sure that the rear end of thesmoke tube is aligned to be flush with the reversion chamber plate!

- After alignment of the new smoke tube, press the front end of the tube byangled bar to the top of the tube hole in the front plate and tack weld it in

position.

- Expand the rear end of the new tube into the hole in the rear tube plate.

- Grind off the welding tack on the front tube end expand also the front tubeend into the hole on the front tube plate.

- Weld the new tube into the front and rear tube plate or into the reversionchamber cover plate according to the approved repair technology.

11 - After completion of each welding run (root run, middle run and final run), it isto be checked according to approved repair technology.

12 - After completion of repair, remove all debris from the water drum and fromthe exhaust gas chambers, uncover the drain and blow down connections,manhole and headhole covers are to be closed and all sealings and gasketsthereon have to be replaced by new ones out of the spare parts stock.

13 - The boiler has to undergo a pressure test according to approved repairtechnology.

14 - All repair steps have to be done exactly according to the approved repairtechnology. Additional requirements of the attending surveyor, which mightcome up during the repair procedure, have to be followed.

repair boiler sms 3 0001 0044 2a

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