Cetane Maintenance. Dan Bemis Dresser Waukesha

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1 Cetane Maintenance Dan Bemis Dresser Waukesha

2 Cetane Maintenance General Hand wheel Maintenance Injection Nozzle Maintenance

3 What is the Hand wheel Assembly Used For? Mechanism used for adjusting the compression ratio. Provides a numerical indication (reading) of the position of the VC Plug in the prechamber Establishes the volume of the pre-chamber and is related to compression ratio. Controls the point at which Ignition Delay occurs during a test.

4 Hand wheel Assembly

5 Micrometer Sleeve: Hand wheel Assembly Marked off in 100 graduations. One revolution of the hand wheel is equal to of movement of the VC Plug in the pre-chamber. Micrometer Scale Arm Works in conjunction with Micrometer sleeve Covers the scale of 0.5 to 3.0 and is graduated in of an inch By determining hand wheel readings for both the sample fuel and that of the two known references we can determine CN of the sample fuel.

6 Variable Compression Ratio Diesel Head / Hand wheel

7 Hand wheel Assembly

8 General Problems / Issues Lack of Proper Cleaning Intervals Hand wheel hard to turn or adjust Damage to Critical Components VC Plug VC Bore in Head Pitting of operating surfaces (VC Plug Face) Use of Barring tools to adjust hand wheel Accelerated Component Wear From Use of Mismatched Head Flanges Poor Calibration Practices Failure to calibrate hand wheel

9 Removal for Cleaning Run engine to warm up for 30 minutes Warm engine will allow for easy removal Set hand wheel scale arm reading to 2.0 Use 50/50 mix light mineral oil and diesel *Shut down engine and Lock out and tag out equipment Remove combustion pickup Remove the 4 3/8-24 hex nuts from cylinder hand wheel flange housing

10 Hand wheel Removal

11 Hand wheel Cleaning

12 Hand wheel Cleaning Every hours or when difficult to adjust Clean by use of non-detrimental practices Scotch Brite (green) Soft wire brushes- copper or aluminum No steel brushes No glass bead blasting Inspection of the VC Plug O.D. Check for heavy wear Check for pitting on combustion face Measurement should be made of VC plug O.D. Replaced if O.D. is below

13 VCP Plug Replacement (If Necessary) Requires complete disassembly of hand wheel Use strap wrench for removal If seized may be necessary to use force Force may damage the washer Do not twist or damage draw bolt Follow F5 O&M Manual directions

14 Measuring The Pre-Combustion Chamber Internal Diameter

15 VC Plug and Bore Tolerances Poor fit between VCP plug and VCP bore in head will not cause: Erratic delay readings Escape of excess combustion gases Excess carbon build up between plug and bore. Instigates tightening of the VCP locking hand wheel with barring mechanisms to seal plug to the bore. (Can damage Plug, Washer and Bore) Understanding bore and plug tolerances will help define maintenance intervals as well as Lifecycle of components.

16 Matched with Cylinder At factory Cetane Cylinder Head

17 Cetane Cylinder Head (Section View Through Pre-Combustion Chamber) Housing is line bored and dowel pinned for proper alignment of the hand wheel assembly

18 Sighting the V.C. Plug In the Pickup Hole Adjust hand wheel until the plug flush with the thread in pickup hole Set Micrometer / Scale to is exact dimension from the V.C Plug to the end of the chamber Cylinders that are oversized will have different thread sighting spec.

19 Hand wheel Calibration

20 Final Comments Clean hand wheel when it is difficult to adjust Avoid the use of barring tools for adjustment during operation Damage will cause instability in readings and results Creates safety risk to others by damaging Hand wheel surfaces Prematurely wears components Complete hand wheel disassembly should occur at every overhaul cleaning, dimensioning and replacement of all critical parts.

21 Final Comments Do not interchange hand wheel housing to other head assemblies. Causes premature wear to hand wheel components and head. Unstable / inconsistent readings Tolerances of critical parts will allow you to determine lifecycle Be preventative with maintenance not reactive.

22 Nozzle Maintenance Why is cleaning important? Consistent atomization of fuel in the engine. Will contribute to stable delay and advance readings Increase accuracy of test variables

23 Injector Nozzle Holder Assembly Nozzle Assembly sits on a injection holder assembly Drilled Passages High pressure passage fed from injection pump via high pressure line Drain bypass Injector Holder components Body Pressure adjusting nut and lock nut Internal Spring Spindle / pintle extension assembly

24 Fuel Injector Nozzle Assembly (Sectional View)

25 Nozzle Pintle (Section View)

26 Common Nozzle Problems Poor Spray Pattern Erratic readings and excess carbon build up at tip Wrong pressure setting Worn spring in holder Worn seat on pintle / poor nozzle to pintle tolerances causes: Dripping Streaking Poor spray pattern Seizing of pintle in nozzle Excess wear or lack of fuel for lubrication Water passage corrosion Inactivity or use

27 Injector Nozzle Maintenance Nozzle Cleaning Clean before each operating period or when consistent erratic advance / delay readings occur Cleaning should be performed in an ultrasonic bath with good detergent Clean pintle separate from nozzle so damage does not occur Rinsed with water after cleaning and then dry with compressed air. Lubricate both nozzle and pintle in diesel fuel before assembly and installation.

28 Injector Nozzle Maintenance Nozzle Cleaning Nozzle and cap nut is torque to holder assembly 50ft.lbs. Nozzle pressure tested each time nozzle is removed and cleaned. Pressure adjusted to 1500 PSI +/- 50 PSI Check for correct fuel pattern / dripping at tip Checked holding pressure just before 1500 PSI. Install new copper gasket at end of nozzle each time assembly is installed in the head Inspect O-Ring in head for wear. Inspect for leakage around nozzle in pre-chamber and at O-Ring with water on.

29 Injector Nozzle Spray Pattern Testing Nozzle should be about 3 from filter paper

30 Typical Injector Nozzle Spray Pattern

31 Injector Assembly With Pickup and Bracket

32 Injector Pickup Gap Start with Approximately and adjust if necessary. Adjust with engine stopped or with drain bypass open.

33 Conclusions Keeping nozzle clean for each operating period Insures stable readings and consistent results Good spray pattern ensures good mixture and more complete combustion Poor spray pattern from worn / dirty nozzle can increase carbon deposits in combustion chamber Leads to more frequent hand wheel cleaning and nozzle cleaning

Injector. General Information CAUTION. Use only the specified injector for the engine.

Injector. General Information CAUTION. Use only the specified injector for the engine. Page 1 of 32 006-026 Injector General Information CAUTION Use only the specified injector for the engine. All engines use closed nozzle, hole-type injectors. However, the injectors can have different part