Obel-P-ProductsNews

New test criterion & resulting product solutions from Obel-P

The slide valve introduced by MAN B&W is now standard on all new MAN B&W engine types andalso the valves are available for retrofit purposes. The introduction of the new slide fuel valvesmeans that we are confronted with the new test criterion, mentioned above.

To meet this new criterion from MAN B&W, we can now offer 2 new product solutions toshipowners, ship management companies and engine builders etc.

The atomising test has been part of the normal maintenance practice for a long time and,therefore, a 100% safe solution is called forI

Consequently we have developeda completely new test pump unit, type VPUD 10g.0, for newengines, where the atomisinq test cannot be eJtecuted at all.-

For vessels already in service, and therefore already equipped with a test rig, we have developedan alternative and lower-priced solution, which can be used on any type of test rig - not only anObel-P test rig! The result is the same as with a new pump unit, Le. the atomising test cannot beexecuted.

MAN B&W recommend that thenew pump unit type is also usedfor the conventional valves.

Conventional fuel valveSource: MAN B&W service letter SL02-403/UM, June 2002

Slide fuel valve

Ib Obel Pedersen AlS. Marine Division. Lerh(~ 10. Dk-2880 Bagsvard. DenmarkPhon!): +45 4498 3833. Fax:.45 4498 1125. E-mail: obel-p@obel-p.dk. Homepage: www.obel-p.dk

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Adapter unit type PPMI1000 for fuel valve test rigs.

· Prevent damaging your new slide valves from MAN B&W· Can be used together with existing test rigs· A safe solution - it i§..impossible for vour crew to atomise fuel injectors with !his adaptor unit

connected.

The package consists of the adapter unit, a high-pressure hose and a valve. The valve is to beconnected inside the cabinet of the existing pump unit at the air side and the high-pressure hose isto be connected at the oil out side.

The working pressure Is shown at the topline on the display. When the openingpressure test Is performed the result Isfrozen and shown on the bottom line on thedisplay.

The adapter unit is operated with a switchbutton. To perform the opening pressure testIt Is turned to the right. To perform theventing function test it is turned to the left.

'Can be usedtogether 't<fltlj,any test rfg .

Ib Obel Pedersen A/S. Marine Division. LerhQ]10, Dk-2880 Bagsvard. DenmarkPhone: +45 4498 3833. Fax: +45 4498 1125. E-mail: obel-p@obel-p.dk. Homepage: www.obel-p.dk

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Obel-P-Products

New pump unit type VPUD 1000

· This type of test rig is now standard maintenance equipment for new MAN B&W2-stroke engines. Make sure you get one with your new buildings.

· The solution for replacement of existing non-repairable test pumps.

The VPUD 1000 differs in several ways from the standard types;VPU 1100.2 MKI or MKII, but the main feature is that the newpump is electronically controlled.

I

~

The a(omisirrtltest cari(lolbe

executed.

As can be seen on the picture,the pump unit is equipped witha digital display. It shows theworking pressure, openingpressure and closing pressurewith an accuracy of +/- 1 bar.

Instead of the old hydraulic high-pressure valve we haveinstalled a switch button wherethe choice of test is made.Switch it to the right andperform the opening pressuretest, switch it to the left andperform the venting functiontest.

It is a new way of thinking andtesting -but an easier way.

Whentl1e openingpressure .of the valveIs reached the preciseopefJing pressure will

be s/;lown on thedisplay.

Ib Obel Pedersen A/S. Marine Division. Lerhqj 10, Dk-2880 Bagsvard. DenmarkPtl0ne: +45 4498 3833. Fax: ..45 4498 1125. E-mail:obel-p@obel-p.dk.Homepage: www.obel-p.dk

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Obel-P-Products

Technical specifications:

Adapter unit type PPMI1 000 for fuel valve test rigs:

New pump unit type VPUD1000:

r-~.

iE

utput pressure:II

Max. 1100 bar at 10 bar air input! Max. 800 bar at 7 bar air input! J ._..___......____...__..._........._....._......_.____._._..__

Airconsumption: 50 Litres per cycle at 10 bar air inputII 36 Litres per cycle at 7 bar and no output pressure

ILM~~~~l1.Z:-Li~';'j;;:(~; ~~;;;;;;;~t;;t~- -=--ilDisPlace~ent procycle: -..J~ cc (1,22 CU.IN~

II Cycle fre~uency/pumping speed: JI60 cycles per min. at 7 bar air input and no output pressure

1~~~' ~~===Jf~;~~1.~Ei~~i~y~~~~.i=- --=. -II ~eight JL100 kg empty

ilDimensions: ~1560 x 950 x 1525 mm

II~~;~;~I;: ~I Single Phase 115/230 V AC

._.__.

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Ib Obel Pedersen AlS. Marine Division. Lerhqj 10, Dk-2880 Bagsvard. DenmarkPhone: +4544983833. Fax: +4544981125. [-mail: obel-p@'obel-p.dk. Homepage: wVllw.obel-p.dk

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!r!i;_;::r-1_:o-_:_-:H:_--:_:_----:_:_-----ionnection high pressure input: I Male coupling CEJN

lL<?on_nectiohigh pressure output: IHigh pressure hose 1 meter with female coupling CEJN

It;UPPI voltage: I

Single phase 115/230 V AC

I Output voltage: I24 V DC

1!.9E:ra!iOn tperatre:_______ _j -100 C to 500 C_...__ _... on...._ _...n.", ................ ..._. .. ............. .__........__n....__....... m....___......_....... ...._....._...... ......'

!1lasfit_on:____________________J Display: class 0,2..m.__._........._.__..._....._._....._.........__.m...................._.... .......---....... ...............-.-.......-....-.............n......

II Weight _I3,5 kgsI ----------------------------------

................ .......-....... ........................-.............................................-.................................--....... ................. ............... .m....,........_.............._.................. ............................

!I Dimensions: I. - -190 x 190 x 150 mm

"PRELIMINARY"..

Pressure testin rocedure for slide fuel valves

This test should first be carried out after 8000 hOlJrs of service."- ~

Only in case of exhaust gas temperature deviation, the valves on theunit in question should be removed between scheduled overhaul.

After 8000 hours, the atomizer should be replaced.After 16000 hours, the complete spindle guide with atomizer should bereplaced.

Preparations

In case slide fuel valves in service has to be tested, it is of utmostimportance to clean nozzle and slid nsure free eforetesting. IS is not one, ere is a risk that the valve is not considered~operating well. With the low capacity of the test pump, the openingpressure can in some cases be judged to be lower than it really is!

Tighten the slide fuel valve in the test stand according to normalprocedure with the disc on the spring housing in line with the housing.

Procedure

The valve is filled up with .!1ydraulic oil by pumping with a pressurebelow the closing pressure tor me non-return valve.---When oil is leaking from the return oil pipe, the hydraulic pressure canbe increased.

It is then observed that the non-return valve is closing and the drainfrom the return pipe is reduced. A small leak from the return pipe can beobserved during building up of the pressure because of the internalleakages in the valve.

It is observed that oil not is leaking from the nozzle before rea~. .openina pressure.

"Theopening pressure is monitored and should be Withi~O and 380bar. It is recommended to adjust the opening pressure to t e mghervalues within the tolerances.The opening pressure test ~ould not be repeated many times

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Because of the limited capacity of the test pump. atomization test mustnot be carried out as this can cause scorina between the slide and thenozzle with conseauential stickina.With this limited capacityof the test pump which normally is less than 5% of the capacity of the fuel pump. the needle will not lift complete andcan cause scorina because of micro movements between nozzle andslide.

Special conditions durina slide valve testina

a)Based on reported strange function during testing from some vessels,we have the following comments:

During testing, the fuel valve was brought up to the specified openingpressure at 330 - 380 bars. After one opening at for instance 360 bars,the valve has continued to open at 230 bar many times.

The reason for this way of operation is that the fuel valve when itcontinuously is pressurised can open at the valves closing pressure. Itwill appear, as ifthe opening pressure is unstable and indicate anopening pressure at a much lower level. However when the valve is inservice in the engine the fuel pressure is reduced to the boosterpressure after each injection, which will cause that the fuel pressure inthe valve not will find a level where the closing pressure is controllingthe opening of the valve.This phenomenon is often seen on fuel valves, which have been takenout directly from the engine and tested without being cleaned, but notso often experienced when testing new valves. However it mighthappen!

b)The valve can..QPen wl!hJl high noise and a kind of atomization whenslowly reaching the opening pressure or in a more quiet way where the Joil is just sprayed out without noise. Both ways of opening is ,.considered as acceptable.

c)Because of the limited needle lift, it will in S

.

ome casp-s hp-observed thcU

-f.

oil is not spraying from all nozzle holes. T!1J~is considered to be ok.-

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