adjustments of fuel oil systems

8/3/2019 Adjustments of Fuel Oil Systems

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Phone: (052) 262 80 10 (24hours)

Diesel After-Sales Service

28.99.07.40

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itzerland

New Sulzer Diesel Ltd

Telex: 896 659 NSDL CH

Diesel After-Sales Service

Telefax: (052) 213 94 83

PO Box 414 CH-8401 Winterthur, Switzerland

Service Bulletin ZAS22

Technical Information to all the Ownersof Sulzer ZA 40S Type Diesel Engines

Adjustments of Fuel Oil Systems

08.11.96

Contents: Page

INTRODUCTION 1

1. GENERAL ENGINE REQUIRE- 1MENTS FOR OPERATION ONHEAVY FUEL OIL

2. FUEL OIL SYSTEM 2

3. FUEL OIL PRESSURE AND 4FLOW DEFINITIONS

4. PRESSURE AND FLOW 5ADJUSTMENT WITH SEPARA-TELY DRIVEN BOOSTER PUMPS

5. PRESSURE AND FLOW 8ADJUSTMENT WITH ENGINEDRIVEN BOOSTER PUMPS

6. GENERAL REMARKS 9

7. SERVICE BULLETINS 10PUBLISHED FOR ZA 40STYPE ENGINES

FUEL OIL


2/161 / 10 Service Bulletin ZAS22

INTRODUCTION

Experience gained so far has shown that the design and commissioning of the fuel oil systemsare not always optimum, particularly in case of a multiengine plant.

When a booster pump supplies fuel oil to several engines, a correct and equal flowdistribution of fuel oil to each engine is of great importance. A flow rate through the engineinjection pumps which is below the minimum specified value can lead to unsatisfactoryinjection behaviour and to cavitation conditions in the fuel injection system.

This information is herewith supplied as a guide for the description of the fuel oil system for

multiengine installations.Its primary task is, however, to give recommendations for the procedure of the adjustmentand equalizing of the fuel oil flow rate through the engines of an installation.

This Service Bulletin should be kept in a separate file in the control room. The respective pagesor tables of the Service Bulletin with modifications to the Operating Manual, MaintenanceManual or Code Book should be copied and filed in the respective Manual or Book.

1. GENERAL ENGINE REQUIREMENTS FOR OPERATION ON HEAVY FUEL OIL

1.1 ZA40S Engines - General Data

Fuel oil viscosity at injection pumps 1317 cSt

Fuel oil service pressure at engine inlet(on engine instrument panel)

810 bar

(specification for earlier engines: 68 bar,but aim for upper side)

Fuel oil pressure in the buffer unit 36 bar

Fuel oil differential pressure peacross theengine fuel injection pumps at standstill

Engine outputkW/cyl.

Minimum differentialpressure pe

(separately driven high pressure booster1) 720 1.3 baru660 1.1 bar

600 0.9 bar

550 0.8 bar

1) For systems with engine driven booster pumps please refer to paragraph 5.



1.2 Engine starting and stopping

Continuous operation on HFO is preferable. Changing over to MDO should be consideredonly if this becomes necessary, for example:

D to flush the engine before maintenance work

D if the booster pump(s) or the heating are stopped when in dry dock (or other reasons).

D due to environmental requirements.

Provided the following conditions are met, ZA40S engines can be started on heavy fuel oil:

D Cylinder cooling water heated to min. 50 C

D Fuel pumps heated by fuel circulation together with trace heating on the engine, systemfuel pipes and components heated

D Heavy fuel oil viscosity at engine inlet to correspond with the requirements (please refer toenclosure ZAS22/5)

D The engine is prelubricated

When these mentioned conditions are met, the engine can be started, stopped and startedagain on HFO.

Designation: HFO = HEAVY FUEL OIL MDO = MARINE DIESEL OIL

1.3 Operation at low load

When running at low load on HFO it is essential that the cylinder cooling water andlubricating oil temperatures are maintained at their service level and that the LT watertemperature at the charge air cooler inlet is not lower than 25 C.

2. FUEL OIL SYSTEM

2.1 General Information

The standard HFO system consists of the following three main groups:

D The storage system: bunker, settling and daily service tanks with transfer pumps

D The HFO treatment or cleaning system

D The pressurized supply system

The principle design of the first two groups for multiengine installation remains the same,except for capacity, whether one considers a fuel system for several engines or for one engineonly.

We must once more, however, stress the extreme importance of correct fuel oil treatment forthe successful operation of engines running on HFO. Proper fuel treatment must be carried

out to remove seawater and abrasive particles including catalytic fines. The key to correctfuel treatment lies in good centrifugal separation, the centrifugal separators being the mostimportant part of the fuel treatment system.



The use of separators without gravity disc, meeting the requirements for future HFOseparation up to 700 cSt at 50C and making the continuous operation of the separator unitseasier, is advisable. As it is usual to have a spare separator, it is of advantage to use itcontinuously to improve the separation results. For the arrangement of separators, refer to

the manufacturer's instructions.

The effective separator throughput must be in accordance with the maximum fuel oil

consumption of the diesel engine plant plus a margin of about 20%. The separators are in

continuous operation 24 hours per day, from port to port.

For the sake of simplicity, the third group including the low and high pressure sidedownstream of the daily tank(s), i. e. from the daily tank(s) to the engine injection equipment,

will henceforth be referred to as the "supply" system.

2.2 Supply system descriptionThe supply shown in enclosure ZAS22/1 is of the so called pressurized fuel oil system type.Pressurized systems are now common for all installations intended for use with lower qualityHFO. It avoids problems with "gassing" at the high supply temperature required by high

viscosity fuels in order to achieve the required viscosity for injection into the engines.

This supply system is mainly characterized by:

A common low and high pressure system for several engines. The low pressure feed pump (7)delivers the fuel oil from the HFO daily tank (3) through the automatic selfcleaning filter (8)into the closed high pressure circuit. To prevent boiling at the high temperatures it is

necessary to maintain the required viscosity, the pressure in the buffer unit (11) is 3 to 6 bar.This pressure is controlled by the pressureregulating valve (9) which returns excess fuel oilback to the feed pump suction side or to the daily tank (3).

From the common booster line, downstream of the endheater (13) and viscosimeter (14),the fuel is then delivered to one or in parallel to several engines.

When several engines are connected in parallel, the correct setting of the fuel flow rate toeach engine can be difficult. The recommended maximum number of main enginesconnected in parallel downstream of the booster pumps is therefore four (4).

For the safety of the vessel, separated fuel oil systems are recommended for vessels with morethan one engine. On vessels with four main engines coupled to two propellers, the separatefuel oil systems should be connected with the engines in such a way that in case one fuel oilsystem fails, each propeller shaft has at least one engine which receives fuel oil from thesystem still in operation.



3. FUEL OIL PRESSURE AND FLOW DEFINITIONS

3.1 Fuel oil flow rate across the engines

When a booster pump supplies fuel oil to several engines as shown on enclosure ZAS22/1, itis necessary to measure and adjust the flow distribution of fuel oil in such a way that eachengine is supplied with the same specified fuel oil quantity. For this purpose, the differentialpressure measured at each engine serves as reference for the flow distribution.

The differential pressure at the engine is to be measured and adjusted with the engines atstandstill during commissioning of the fuel oil system in an installation with separately drivenhigh pressure booster pumps. Engines equipped with builton booster pumps have to be runat nominal speed without load.

After maintenance work on the fuel oil system a check on the fuel oil supply to each engine is

required.

3.2 Measuring the differential pressure

The differential pressure is measured between the inlet and outlet of the injection pumps.More recent engines have now a switchingover connection with two cutoff valves to thepressure gauge in the instrument panel allowing the pressure before and after the injectionpumps to be measured. The difference between these two pressures gives the differentialpressure across the injection system, see enclosure ZAS22/3.

Earlier supplied engines require a small modification for measuring as per enclosureZAS22/4.

The fuel flow is only correct when the differential pressure (pe) is the same for all enginesconnected to the same fuel oil system and amounts to:


Minimum differentialpressure pe.

720 1.3 bar

660 1.1 bar

600 0.9 bar

550 0.8 bar

The differential pressure is measured at standstill with electricmotor driven booster pump(no pressure pulsations).



3.3 Delivery pressure

In order to prevent any water (which may be present), from boiling at the high temperature(necessary to maintain the required viscosity), the lowest pressure in the closed booster

circuit must be above the vapour pressure at which this water could flashoff to steam.Therefore the min. required pressure p at the booster pump suction side (28) has to be at least1 bar above the corresponding vapour pressure but not lower than 3 bar (please refer to thefollowing diagram).

1

2

3

4

5

6

7

100 110 120 130 140 150 160

fuel oil temperature [C]in buffer unit (11)

min.requiredpressure[bar]

onboosterpumpsuct

ionside(28)

3.4 Maximum permissible operating pressure

It must be ensured that the max. working pressure of all system components are not exceeded.Therefore the max. pressures of these components have to be verified and the relevant safety

valves to be checked accordingly.

4. PRESSURE AND FLOW ADJUSTMENT OF THE FUEL OIL SYSTEM WITH

ELECTRIC MOTOR DRIVEN BOOSTER PUMPS ACCORDING TO ENCLOSURE

ZAS22/1

4.1 Preliminary conditions before adjustment:

D All engines at standstill

D Whole plant on MDO or HFO. For the latter case, heavy fuel is heated to obtain therequired viscosity at the injection pumps according to enclosure ZAS22/5

D Feed and booster pumps in operation

D Fuel oil circulates through all engines



4.2 Checks and adjustments

4.2.1 Safety valves

Check and set the safety valves (24 and 25) of the feed and booster pumps (7 and 12, also on

standby pumps) to their max. admissible operating pressure or p between discharge andsuction side respectively. It has to be made sure that these valves are completely closed undernormal service conditions in order to avoid any internal bypass possibility.

4.2.2 Pressure at the booster pump

Check the pressure at the booster pump suction (28) side which has to be within the followinglimits:

D Minimum as described under paragraph 3.3

D Maximum (about 6 bar), depending on

-Max. admissible operating pressure of the feed pump-Max. admissible operating pressure of the buffer tank including an adequate margin to

the setting of its safety valve

If necessary, the pressure level at the booster pump suction side can be adjusted with thepressure regulating valve (9).

Please note: Especially simpler types of pressure regulating valves do not hold the pressureabsolutely constant. Slow pressure fluctuations up to 0.5 bar in the low pressure circuit,

which also influences the pressure level in the booster system, can be tolerated.

Furthermore the pressure difference across simple, springloaded regulating valves is flowdependent i. e. the pressure in the buffer unit decreases with increasing fuel consumption.

4.2.3 Fuel oil pressure before engines

For earlier engines the nominal range of the fuel oil pressure before engine amounts to 6 8bar (aim at upper side). Later engines are specified for a fuel inlet pressure of 810 bar.

Important:

D The design pressure (normally 16 bar, but to be verified) of the various system componentsmust not be exceeded. If the design pressure does not allow such a high pressure level, thepressure before the engines has to be set at the lower limit or even below the specified rangefor the time being.

D At this stage the overflow valve (18) must not yet limit the fuel oil pressure (to be settemporarily higher).

D All pressure retaining valves (17) have to be set to the same position i. e. the distance "x"on enclosure ZAS22/2 should be about the same on all engines (as a preadjustment).

If necessary the fuel oil pressure before the engines can be adjusted as follows:

The pressure level of the whole high pressure system can be varied by means of the pressureregulating valve (9) within the limits as specified. If this procedure is not sufficient thepressure level can be further adjusted with the pressure retaining valves (17) on the engines

which have to be shifted equally for the time being i.e. same amount of turns (please refer to

enclosure ZAS22/2) and note down the final pressure after booster pump(s) (29).

Attention: The retaining valve KS 87085 must be of the present design or has to be modified

accordingly to avoid fuel oil gushing out from the valve by unscrewing the spindle completely(please refer toService Bulletin ZAS12).
http://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdfhttp://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdfhttp://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdfhttp://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdf



4.2.4 Overflow valve

To adjust the overflow valve (18) proceed as follows:

D Adjust the overflow valve (18) to its lower set value.

D Shut off the supply inlet lines of all engines by closing the valves (23).

D Adjust the overflow valve until the pressure at the outlet of the booster pumps (29) is 23bar higher than the pressure noted down before (the design pressure of the componentsbetween buffer unit and engines must not be exceeded).

D Reopen all the valves (23) in the supply lines to the engines.

4.2.5 Fuel oil flow / quantity

To adjust or equalise the differential pressures (pe) proceed as follow:

D Measure the differential pressure (pe) at each engine at standstill as mentioned underparagraph 3.2.

D Equalize then, only if it is necessary, the differential pressure (pe) by means of thepressure retaining valve (17) only in such a way that it will be the same on each engine of asystem.

Important: Dirty or clogged fuel oil indicator filters (15) do influence the fuel oildistribution, therefore the fuel filters have to be checked for cleanliness prior to themeasurements.

Note: At the engines with higher differential pressure (pe), the pressureretaining valve (17)

should slightly throttle the fuel flow and vice versa. Please refer to enclosure ZAS22/2 for thevalve opening characteristic.

If the values mentioned under paragraph 3.2 are not achieved, the following items have to bechecked:

D Dimension of the booster pumps: The capacity q of the fuel oil booster pumps shouldamount to q 0.65 * Ptot [m

3/h]Ptot= total engine power installed at MCR [MW]

D Are all bypass possibilities in systems and components eliminated?

D Condition of the booster pumps: Are there any additional losses inside the pump (e. g.

worn internals, defective safety valve etc.)?



4.3 Final conditions after adjustment

4.3.1 Engines at standstill


Minimum differentialpressure pe

720 1.3 bar

660 1.1 bar

600 0.9 bar

550 0.8 bar

The fuel flow is only correct when the differential pressure (pe) is the same for all enginesconnected to the same booster system.

4.3.2 Engines in operation

Fuel oil pressure at each engine inlet : within 8 10 bar, normal 9 bar

within 6 8 bar for earlier engines,but aim for upper side

If necessary an additional fine adjustment by means of the pressure regulating valve (9) in thefeed system within the limits as described in paragraph 4.2.2 can be carried out at service load.

Note down the final pressures before and after feed and booster pumps (26, 27, 28, 29).

5. PRESSURE AND FLOW ADJUSTMENT OF A FUEL OIL SYSTEM WITH ENGINEDRIVEN BOOSTER PUMPS (CONCERNS A FEW PLANTS ONLY)

1. Check and set all bypass and relief valves on:

D Feed pumps

D Buffer unit

D Engine driven booster pumps, the builtin overpressure safety valve is factoryadjusted to p discharge/suction = 10 bar

D Fuel oil end heater

2. Whole plant preferably on MDO than on HFO. For the latter case, heavy fuel isheated to obtain the required viscosity at the injection pumps according to enclosureZAS22/5.

3. Engine running at nominal speed without load.

4. The feed pressure at the engine driven pump suction side is not lower than describedunder paragraph 3.3.

5. If necessary increase by means of the pressure regulating valve (9).

6. Measure the heavy fuel oil pressure at the engine inlet and adjust to 810 bar byincreasing the pressure level of the whole high pressure side by means of the pressure

regulating valve (9) and / or adjust the pressure at the engine by means of the pressureretaining valve (17). See also enclosure ZAS22/2.

7. Measure the differential pressure (pe) as mentioned under paragraph 3.2.

Note: Sufficient damping of the pressure gauges is required.



6. GENERAL REMARKS

6.1 RecheckAfter any possible corrections of the engine inlet pressure as described under paragraph4.3.2 or manipulations in the systems etc., the differential pressures (pe) have to be checkedonce more and compared to the values mentioned under paragraph 4.3.1

6.2 Pressure regulating valve (9)

With a pneumatically controlled pressure regulating valve (9), the delivery pressures after thefeeder and booster pump can increase above limits if the control air pressure fails.

Note: Do not decrease pressure by means of safety valve (25) but rather temporarily by meansof safety valve (24) at the feeder pump or preferably by mechanical adjustment of regulating

valve (9) until air supply is restored.

6.3 Standby pumps

The measurements under paragraphs 4 and 5 have also to be carried out with any standbypump.

ENCLOSURES:

Fuel System Layout ZAS-22/1

Pressure Retaining Valve KS 87085 ZAS-22/2

ZA40S Control of Fuel Pressure in the Supply and

Return Pipe (with Measuring Device on Engine) ZAS-22/3

ZA 40S Control of Fuel Pressure in the Supply and

Return Pipe (Without Measuring Device on Engine) ZAS-22/4

Viscosity - Temperature Diagram ZAS-22/5

New Sulzer Diesel Switzerland Ltd has issued this Service Bulletin with their best knowledge and

ability. However, New Sulzer Diesel Switzerland Switzerland Ltd can not take any liability forany or all information contained in this or any other Service Bulletin.

Changes of any nature to the form and or to the content of this or any other Service Bulletin aspublished by New Sulzer Diesel Switzerland Switzerland Ltd, are not permitted.



7. SERVICE BULLETINS PUBLISHED FOR ZA 40S TYPE ENGINES

We have so far published the following Service Bulletins which are valid for ZA 40S type engines:

Z-6.2 dated 31.07.92 Assessment of Main and Connecting Rod Bearings

Z-7 dated 19.07.85 Flushing Instructions

Z-8.1 dated 13.12.91 Undersized Bearings and Reconditioning of Crankshafts

Z-9.2 dated 28.09.93 Lubricating Oil Treatment and Requirements

ZAS-1.1 dated 20.10.93 Cylinder Liner Overhaul

ZAS-2 dated 06.11.92 Grinding of Inlet / Exhaust Valves and Seats, New Valve Seat andNew Relief Valve Design

ZAS-3 dated 10.06.93 Oil Scraper Rings

ZAS-4.3 dated 25.03.97 Top Piston Ring

ZAS-5 dated 03.12.93 Instruction for Testing of Fuel Injection Nozzles

ZAS-6 dated 01.04.94 Ring for Rotating Piston for ZA 40S Type Engines

ZAS-7 dated 05.04.94 Adjustments and Maintenance Requirements on Oil Mist Detector

ZAS-8 dated 05.04.94 Turnomat for Exhaust Valves and Rotocap for Inlet Valveson ZASType Engines

ZAS-9 dated 01.06.94 Exhaust Pipe Expansion Bellows

ZAS-10 dated 01.08.94 High Temperature Cooling Water System

ZAS-11 dated 01.03.95 Cylinder Liner with a Thread in the Upper Part of the Bore

ZAS-12 dated 01.03.95 New Spindle Design for Pressure Control Valve KS 87085

ZAS-13 dated 31.03.95 New Inlet Valves

ZAS-14 dated 01.06.95 New High Pressure Fuel Pipe Assembly

ZAS-15 dated 10.08.95 New Fuel Injection Nozzle Specification

ZAS-16 dated 10.08.95 Flow Control Valve KS 72126 for Cylinder Lubrication

ZAS-17.1 dated 04.04.97 ABBTurbochargers Type VTR ..4 After Sales Service Information

ZAS-18 dated 17.11.95 Tightening Instructions

ZAS-19 dated 17.11.95 New Piston Ring Fitting Tool

ZAS-20 dated 17.11.95 New Spring Cage KS 28042 for Rocker Gear

ZAS-21 dated 22.03.96 Differences in the Drive for the Cylinder Lubrication betweenEngines with 660 kW/Cyl. and 720 kW/Cyl.

ZAS-22 dated 08.11.96 Adjustments of Fuel Oil Systems

ZAS-23 dated 19.11.96 Modification to the Oil Mist Detector

ZAS-24 dated 28.01.97 Alphabetical Index of Topics of Service Bulletins

Should you not be in possession of the above mentioned documentation suitable for your plant, kindly contact

your local New Sulzer Diesel representative for your copy.


12/16Service Bulletin Enclosure ZAS22/ 1

8EmergencyMDOsupplyline

7

5

From transfer pump

2

20

inusewhenfillingair

couplingconnectiononly

Flexiblehosequick

Airoutlet

From diesel oil separator

9

19

16

15

13

To air vent manifolds

12 11 10

Airinlet7bar

17

15

To additional engines

PI

1

From heavy fuel oil separator

18

LAL

DAH

A

LAL

PI

6

1

To heavy fuel oil separator

20

Note: The returnpipe may also beled to tank 3

PIPI

LAH

19

14

From additional engines

16

DI

DAH

DAH

43

VAH

17

PI

PI PI

PI

PI

DI

DI

TI

1 Main engine

2 HFO settling tank, heatable and insulated

3 HFO daily tank, heatable and insulated4 MDO daily tank

5 Threeway valve, manually or remotely operated

6 Suction filter, heatable

7 Low pressure feed pump

8 Automatic selfcleaning filter

9 Pressure regulating valve

10 Flow meter

11 Buffer unit

12 High pressure booster pump13 Fuel oil end heater

14 Viscosimeter

15 Duplex filter, heatable

16 Inlet to engine fuel injection pump

17 Pressure retaining valve fitted on engine18 Overflow valve

19 Fuel oil leakage

20 Fuel oil monitoring

21 Shutoff valve after feed pump

22 Shutoff valve after booster pump

23 Shutoff valve at engine inlet

24 Safety valve on feed pump

25 Safety valve on booster pump

26 Pressure gauge before feed pump

27 Pressure gauge after feed pump28 Pressure gauge before booster pump

29 Pressure gauge after booster pump

FUEL SYSTEM LAYOUT

21

22

23

23

25

25

24

24

27

27

29

29

28

28

26

26



123

5

67

9

10

4

8

1 Hexagon for spanner2 Washer3 Locking nut4 Locking plate

5 Nipple6 Adjusting spindle7 Oring

8 Housing9 Sleeve10 Compression spring

Pressure retaining valve KS 87085

Valve openingcharacteristic

adjusting

range

Attention: The retaining valve KS 87085 must be of the present design or has to bemodified accordingly to avoid fuel oil gushing out from the valve by unscrewing thespindle completely (please refer toService Bulletin ZAS12).

Fromfuel pumps

Engine outlet(to buffer unit)

differential pressureacross valve

Fig. 1 Fig. 2

Working principle of the pressure retaining valve:The sleeve (9) is pressed downwards against the compression spring (10) until the fuel enteringthe valve can pass between the sleeve (9) and the spindle (6) to the outlet. This requires adifferential pressure across the valve depending on the position of the spindle (6). The more thespindle is inserted into the valve body the more the fuel oil differential pressure across the valveincreases which is necessary to open the valve due to the increased compression of the spring(see Fig. 2).Fig. 1 shows the spindle in its initial position as the sleeve (9) is in its upper end position. If thespindle is screwed upwards beyond this point the valve becomes inoperative because the fueloil can pass the valve without pressing down the sleeve.

" X "
http://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdfhttp://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdfhttp://chknsd_03/DATA/ALLG/NSD/SERVICE/Bulletin/ZAS%20Service%20Bulletin/ZAS-12.pdf



Cutoff valves

(one is to be closed)

Fuelpressure

to pressureswitch

supply line

return line

Instrument panel on the engine

limiting plate

ZA40SControl of fuel pressure in the

supply and return pipe(with measuring device on engine)

Connecting box

NORMALPOSITION



Supply

Return

Pressureretainingvalve

Orifice (3 Stage)

Fuel injection pumpFuelpressure

Instrument panel on the engine

Pressure gauge(for temporary use)

ZA40SControl of fuel pressure in the supply and return pipe

(without measuring device on engine)

To be closed bycap nut after use

Isolating valves

Square flange

Flange for:supply line:Connection to pressure gauge

on engine instrument panelreturn line: to be blanked off with a plug

screw or not drilled through

Square flange with isolating valve for inlet and outlet

Thread size according tothe connection used

Valve must be fitted

as close to theflange as possible

All fittings used must be of qualified standard and made of steel!


16/16

V I S C O S I T Y T E M P E R A T U R E D I A G R A M

(Typical Values of Petroleum Fuel Oils)

91.7055b

Oils can be pumped only with difficultyor not at all

Recommended viscosity before fuel injection pumps

Example:

To obtain the recommended viscosity before fuel injection pumps a fuel oil of 150 mm@ /s (cSt) at 50_Cmust be heated to 108 to 120_C.

adjustments of fuel oil systems

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