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RB-13 ENERGYWORKS- CARBALLO EXTENSION OF
THE LIFESPAN OF EXHAUST VALVES |
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rb bertomeu, S.L. |
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INDEX 1- TESTS PLANNING AND
CONCLUSION
2- REPORT OF
FINAL INSPECTION AT
TBO 6,107 H WITH PHOTOGRAPHIC REPORT
OF ALL EXHAUST
VALVES
3- REPORT OF
PARTIAL INSPECTION AT
TBO 5,318 H WITH PHOTOGRAPHIC REPORT
OF THE 2 CHECKED
EXHAUST VALVES
4- REPORT OF
PARTIAL INSPECTION AT
TBO 4,669 H WITH PHOTOGRAPHIC REPORT
OF THE 3
CHECKED EXHAUST VALVES
5- REPORT ABOUT THE USE OF MAGNESIUM AS A SOLUTION AGAINST THE CORROSION PROBLEMS, DERIVED FROM THE COMBUSTION OF HEAVY FUEL OIL. (Requested by Mr. Hans-Jörg Stegmann from Deutz AG)
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1 - TESTS PLANNING
AND CONCLUSION
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1.1 PRECEDENTS
Preliminary note: This study is written in reverse chronological order. The last results are at the beginning and go back to the initial results, at the end of the document. Please read the November 2015 update, in section 1.4.
The additive for heavy fuel oil “rb bertomeu” beco F1/ASF is used with remarcable success to fight against the heat corrosion in Diesel engines. This additive is being used since 1995-1996 in Spain, in many power plants which are equipped with Deutz Diesel engines.
Deutz Iberia, who already knew this fact from Deutz Service and also from the information generated by rb bertomeu S.L. during the last years , suggested to carry out a test on extension of the lifespan of the exhaust valves (increasing of TBO), as a confirmation of the Certification letter for the “rb bertomeu” beco F1/ASF additive, issued by Deutz Iberia in 1999 and also to verify the assertions of rb bertomeu S.L. who, in their studies, arrives to the conclusion that after using the mentioned “rb bertomeu” beco F1/ASF additive, is possible to get a TBO increase of a minimum of 50%, of exhaust valves in Diesel engines working with heavy fuel oil.
The TBO foreseen by Deutz is 3,000 hours in plants where heavy fuel oil is used and this TBO is easily reached when the additive “rb bertomeu” beco F1/ASF is used (in the same plants, before using that additive, only 2,500 hours of TBO were reached, and some times even with some difficulties). During the last years several tests to increase the TBO up to 4,500–5,000 hours, were carried out successfully, in all cases, in some plants where that additive is normally used.
Taking into account these precedents, Deutz Iberia proposed that the objective of the new test should be to reach a 6,000-Hour TBO, which means doubling the usual TBO.
1.2 TEST PLANNING
Deutz Iberia planned the test in collaboration with EnergyWorks Carballo (previously called Calvo Energía) and, of course, with rb bertomeu S.L.
The execution of the test followwed these points :
Engine to be checked: Engine No. 1 of the power plant of Works-Carballo (Deutz Id: 010081) Engine type : BV 16M 640
Fuel : Heavy fuel oil
Fuel additive : “rb bertomeu” beco F1/ASF
Starting up the test : After inspection of 15,800 Hours
Test carried out in parallel : Valves with seat at 30º C: A1A – A1B – A2A A2B – B1A – B1B
Installed exhaust valves: Mainly re-utilized exhaust valves , mechanically rectified (with 1 – 3 uses each one) Material of Sleeves : Nimonic Material of Baskets : Stellite
Inspections to be made: 1st : Approximately at 4,500 H , because this is an already reached value, in other tests.
2nd : Approximately at 5,300-5,500 H
3rd : Last inspection at 6,000 H approximately if it is possible, and as a maximum value for this test.
1.3 CONCLUSIONS AFTER FINALIZING THE TEST
The test was given as successfully concluded on 28-March-2002 , after being carried out all foreseen inspections and after being reached a TBO of 6,107 Hours. It is to be mentioned that apparently, the engine was able to follow in operation without shutting down for revision. According to this, we consider that a TBO higher than 6,000 hours could also be possible.
In the following chapters we include the corresponding reports for each carried out inspection , with photographic reports of the checked exhaust valves.
Main conclusions are the following , under our point of view :
A- A TBO of 6,107 hours has been reached without difficulties.
B- During the test only was absolutely need to change the following valves, all them between 3,000 and 6,000 hours:
A8B : changed at 5,400 hours due to blow out A5 (B) : changed at 5,707 hours due to blow out (1) B1A : changed before 4,669 horas due to blow out (this is an exhaust valve with seat at 30º , installed for another type of test by Deutz)
(1) It is not possible to identify exactly if it is the valve “A” or “B”, but most probably is “B” because “A” has better aspect in the photos. This valve has a defect in its mechanical rectification angle (see inspection report and photograph).
C- During the final inspection it was only detected 1 valve sleeve with beginning of blow out and 1 valve basket with corrosion (not being possible to recovery), and another 3 valves with beginning of corrosion, but being apparently possible its recovery by mechanical rectification of seats. With these results, it is possible to say that the test has been easily passed.
The remaining 28 valves only have some compactations in the seats of spindles and baskets, and some hammering signals in the seat of 10 baskets. Nevertheless, all these 28 valves will be recovered and re-used after a very soft mechanical rectification of their seats.
D- Dismounting valves operation was carried out without difficulties, by using a normal crane for 29 valves and the hydraulic jack for the other 3 valves. Dismounting cylinder heads was not necessary in any case. Only 1 cooper gasket with beginning of corrosion (without blow out) was found from among 32 existing cooper gaskets. Both points are very important to get an increment in the operational TBO, avoiding possible difficulties of seizure in the valve dismounting operations.
E- Regarding the obtained results, it seems possible that the reached TBO of 6,000 h could be increased up to higher values, because of the reached level of corrosion can be considered low. Thinking about 8,000 hours without serious corrosions, seems could be the next objective, but it is necessary to think of some intermediate maintenance action to prevent and avoid the appearance of seizure in the cylinder heads or blow out in the cooper gaskets.
In this regard, Mr. Tomás López from Energyworks Carballo, proposed a way to avoid that kind of problems, in case that TBO was increased up to 8,000 hours. His suggestion consist, broadly speaking, in the introduction of a short intermediate level of maintenance at 4,000 hours, to make the following operations :
a) Change of all cooper gaskets. b) Cleaning and re-greasing all valve boxes with the normal anti-seize product.
1.4 NOVEMBER 2015 UPDATE
Given the success when the test finished and the Energyworks-Carballo company satisfaction, they have used the additive up to date, further extending the TBO and reaching 7,200 hours as you can read in the letters of reference.
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2 - REPORT OF FINAL INSPECTION AT TBO = 6,107 H WITH PHOTOGRAPHIC REPORT OF ALL EXHAUST VALVES |
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ENERGYWORKS CARBALLO (CALVO ENERGIA)
TESTING THE EXTENSION OF THE EXHAUST VALVES LIFE UP TO 6,000 H IN ENGINE No. 1 ( Deutz Id: 010081)
FINAL INSPECTION AT TBO = 6,107 Hours
Hours in engine meter : 21,907 h.
Final inspection date : 28/03/2002 Date of valves inspection in workshop of Deutz Service Vigo : 19/04/2002
Final control made by : Mr. Tomas López - EnergyWorks Carballo (Calvo Energía) Mr. Hans Ruckert - Deutz Iberia Hans-Jörg Stegmann – Deutz A.G. Mr. Rosendo Bertomeu - rb bertomeu S.L.
VALVES CHECKED : All the exhaust valves of the engine
PHOTOS TAKEN : All valves of the engine. See photographic report.
FUEL ADDITIVE : “rb bertomeu” beco F1/ASF
CONDITION OF VALVES AFTER REACHING A TBO OF 6,107 H :
See the Residues Table TBO at the end of this section.
Concerning the 32 exhaust valves, dismounted from Engine No. 1 , at 6,107 hours of TBO , which have been analyzed jointly by DEUTZ , ENERGYWORKS and RB BERTOMEU , we remark the following points :
1- There is only 1 valve , A3A , with beginning of blow out in the sleeve and some corrosions on the basket seat (apparently without possibility of recovery). 2- There are only 3 baskets with beginning corrosions in its seats, A6B, B3A and B3B, but all 3 with possibilities of recovery by mechanical rectification. 3- There are not corrosions in the rest of valves. Only is possible to see some compactations or hammering signals, due to the solid residues coming from the combustion of the fuel oil. 4- During total TBO of 6,107 hours, only the following valves were substituted, in spite of almost all installed valves for the test were re-used, with 1 – 3 mechanical rectifications each one.
Valve B1A , changed some days before 4,669 Hours . This valve belongs to a group of valves with seat at 30º, installed by Deutz for a parallel test. The valve B1B, in good condition, was dismounted at the same time to be inspected with B1A (blowed out) in Deutz – Mannheim.
Valve B8B , changed at 4,669 Hours , due to beginnig of corrosions. The change was made in the first inspection (see report), without having necessary, by agreement to check the possible repetition of corrosions in this point. In the final inspection there is no found corrosion in this valve.
Valve A8B , changed at 5,400 Hours , due to blow out.
Valve A5 (not identified exactly if “A” ó “B” , but most probably “B”) , changed at 5,707 hours, after being blown out. In the photograph , identified as Valve A 5 at the end of photographic report, it is possible to see a defect in the grinding angle of the seat, which could be the primary cause of blow out.
5- Concerning the 27 remaining valves, 23 have surpassed the TBO of 6,107 hours, without corrosions in the final inspection and the other 4 have also surpassed the TBO of 6,107 hours but with the corrosions already mentioned in points 1 and 2.
6- In the final inspection we have detected 2 heads of sleeve valve with thermal fatigue and other 2 sleeve valve were the thermal tatigue is just starting. This probabily can be considered as normal by Deutz, taking into account that valves are not new. (Anyway , this must be avaluated by Deutz since thermal fatigue is not related with chemical corrosion).
see: Residues Table TBO see: Photographic Report
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3 - REPORT OF PARTIAL INSPECTION AT TBO = 5,318 H WITH PHOTOGRAPHIC REPORT OF THE TWO CHECKED EXHAUST VALVES
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ENERGYWORKS CARBALLO (CALVO ENERGIA)
TESTING THE EXTENSION OF THE EXHAUST VALVES' LIFESPAN UP TO 6,000 H IN ENGINE No. 1 ( Deutz Id: 010081)
PARTIAL INSPECTION AT TBO = 5,318 Hours
Hours in engine meter : 21,118 h.
Date of inspection : 26/01/2002
Made by : EnergyWorks Carballo (Calvo Energía) Deutz Iberia rb bertomeu
VALVES CHECKED : B8A - B8B
These valves were chosen by CALVO for the second partial inspection because of the same valves were inspected in the first inspection on 24/11/01 at TBO= 4,669 h. Please note that the valve B8A was changed in that first inspection, but only to check the possible repetition of anomalies.
PHOTOS TAKEN :
Photo No 1 : Sleeve of Valve B8A , after cleaning to verify possible corrosions
Photo No 2 : Sleeve of Valve B8B , after cleaning to verify possible corrosions
Photo No 3 : Basket of Valve B8A , after cleaning to verify possible corrosions
Photo No 4 : Basket of Valve B8B , after cleaning to verify possible corrosions
FUEL ADDITIVE : “rb bertomeu” beco F1/ASF
VALVES' CONDITION:
See the Residues Table TBO at the end of this section. Both checked valves are in good condition and, consequently are re-instaled in the same position. The Valve B8A, changed in the first inspection, has not, with 649 hours in operation, eny repetition of corrosion anomalies that were detected in that first inspection.
NEXT INSPECTION :
It was decided , between Deutz Iberia and Calvo Energía, that into the following two weeks, when the valves for the overhaul of engine No. 1 were prepared , the Engine will be stopped and the test on extension of the life of valves will be finalized. In this next inspection , all valves will be changed and checked also by rb bertomeu, in order to make the final report about the condition of that valves after the test.
see: Residues Table TBO see: Photographic Report
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4 - REPORT OF PARTIAL INSPECTION AT TBO = 4,669 H WITH PHOTOGRAPHIC REPORT OF THE 3 CHECKED EXHAUST VALVES.
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ENERGYWORKS CARBALLO (CALVO ENERGIA)
TESTS ON EXTENSION OF THE EXHAUST VALVES LIFE UP TO 6,000 H IN ENGINE No. 1 (Deutz Id: 010081)
PARTIAL INSPECTION AT TBO = 4,669 Horas
Hours in engine counter : 20,469 Date of inspection : 24/11/2001 Realized by : EnergyWorks Carballo (Calvo Energía) Deutz Iberia rb bertomeu
VALVES CHECKED : B8A - B8B (Normal valves at 45º)
These valves were chosen by CALVO for checking because they belong to the cylinder that has been historically operating at higher temperature, and they have more possibilities of corrosion.
Experimental valves with seats at 30º : A1A – A1B – A2A – A2B – B1A – B1B
Note important : An additional checking was made on the valves B1A and B1B, (experimental valves with seat at 30º) since the valve B1A was changed few days before due to blow out. Both valves B1A (blowed out) and B1B (in good condition) were sent to Deutz Mannheim to be checked. Normal valves were installed at 45º.
PHOTOS TAKEN : Photo No 1 : Sleeve of Valve B1A , blowed out before revision at TBO 4,669 H Photo No 2 : Sleeve of Valve B8A , before cleaning Photo No 3 : Sleeve of Valve B8A , after cleaning , to verify possible corrosions Photo No 4 : Basket of Valve B8A Photo No 5 : Sleeve of Valve B8B , before cleaning Photo No 6 : Sleeve of Valve B8B , after cleaning , to verify possible corrosions Photo No 7 : Basket of Valve B8B
FUEL ADDITIVE : “rb bertomeu” beco F1/ASF
VALVES' CONDITION: See the Residues Table TBO at the end of this section. It was decided to change the valve B8A, with only “beginning of corrosion” (mild corrosion), to verify possible repetition of that anomaly in this point, in the next inspection.
NEXT INSPECTION : Around January, 19th , 2002, after the engine has approximately 21,100 working-hours and with a TBO of 5,300 hours since the beginning of the test. It is foreseen to check again the valve B8B and the valves of the cylinder that had been working at the higher operational temperature.
see: Residues Table TBO see: Photographic Report
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5 - REPORT ABOUT THE USE OF MAGNESIUM AS A SOLUTION AGAINST THE CORROSION PROBLEMS, DERIVED FROM THE COMBUSTION OF HEAVY FUEL OIL. (Requested by Mr. Hans-Jörg Stegmann from Deutz AG) |
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The Technical Document "RB-12 Magnesium as a solution against the corrosion problems derived from the combustion of the heavy fuel oil or crude oil." scientifially shows how the theoretical damage produced in the engine after using heavy fuel oil treated with Magnessium oxide, cannot be produced when using the additive with soluble magnessium “rb bertomeu” beco F1/ASF, because there is no magnessium oxide present, solid nor liquid, before the combustion nor after the combustion of fuel oil. The “rb bertomeu” beco F1/ASF additive is formulated, among other components, with Organic salts of Fatty acids (molecules - trade secret) SOLUBLE in HYDROCARBONS.
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©
rb bertomeu, S.L. - Pol. Ind. Fondo de Llitera, Par. 82-83 - E-22520 Fraga,
Huesca (Spain) Tel.: +34 974 47 48 04 /
+34 630 43 08 43 |