C-130FuelControl-8__TestInstruction.pdf.pdf

TO 2G-GTCP85-43-9

WP 006 00

OO-MAN-2015-00150

(Comment Only: The following changes apply to corresponding paragraph numbers in T.O. 2G-GTCP85-

43-9, WP 006 00)

3.a The fuel control unit, model No. 3609150-8, see Figure 1.1, consists of a fuel pump assembly, governor assembly, acceleration limiter valve, solenoid valve with electrical connector, filter element, fuel inlet connection, fuel outlet connection, fuel drain connection, control air pressure connection, pressure gage tap, and fuel seal drain.

3.b The fuel pump assembly is a two gear, positive displacement type. The governor assembly consists of a bearing mounted sleeve and shaft, flyweight carrier, and spring loaded flyweights.

3.c The acceleration limiter valve is a poppet valve loaded against its seat by a spring and air pressure against a diaphragm assembly.

3.d The fuel control unit limits fuel pressure and flow to the fuel atomizer assembly of the gas turbine engine during engine start cycle, thus controlling acceleration and exhaust gas temperatures.

3.e To assist in repair, the fuel control unit has been divided into four sections. The sections are fuel solenoid, governor, acceleration limiter, and fuel pump and housing assembly.

3.f See Table 1.1 for fuel control unit, model No. 3609150-8, specifications.

3.g See Figure 1.2 for fuel control unit schematic diagram.

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Insert the following Section “10. Testing, Model Number: 3609150-8” after Section “9. Testing” and renumber Sections “10. Troubleshooting” and “11. Preservation” to “11 Troubleshooting” and “12.

Preservation”, respectively.

10. TESTING, Model Number: 3609150-8

NOTE

Refer to T.M. SE-876-03-1053 for operation and maintenance of 281600-7-1/281600-7-1-P1 test stand assembly.

a. Depreservation (If necessary)

CAUTION

Do not contaminate the calibration fluid in the test stand with preservation fluid removed from fuel control unit.

WARNING

Fuel and calibration fluid (43-44A) are toxic to the eyes, skin, and respiratory tract. Eye and skin protection required. Use only in a well-ventilated area.

(1) Plug all ports in fuel system except fuel-pump inlet and fuel-control discharge. Apply 24 to 28 Vdc to solenoid to open solenoid. Supply a source of fuel or calibration fluid to the fuel-pump inlet at a pressure of 5 to 25 psig. Operate pump at 200 to 500 rpm until all oil has been removed from fuel control unit and discharge stream contains pure calibration fluid.

b. Preparation for Test

(1) Use 281600-7-1/281600-7-1-P1 test stand assembly or provide a test setup using items (Figure 25, 1 through 16) and capable of running the unit to the input parameters and output measurements specified in Table 8, using instrumentation capable of meeting the accuracy requirements of Table 7, and also capable of producing the required back-pressures of Table 5.

(2) Service test stand assembly using calibration fluid (43-44A).

(3) Install fuel control unit with filter element down, on mounting pad of test stand assembly, checking mesh of fuel control unit drive shaft with drive shaft splines of test stand assembly. Ensure input shaft will turn in a clockwise direction when viewing from input shaft end. Attach the fuel control unit to the test stand using all 4 mounting holes in the fuel pump housing (Figure 14, 101).

(4) Hook up fuel control unit, as required, to meet parameters specified in Tables 7, 8, and 9.

(5) Maintain a complete and accurate record of test run.

(6) Refer to paragraph 11 “Troubleshooting” for aid in correcting problems encountered during testing.

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c. Fuel Leakage Check

(1) Throughout the entire testing procedure there shall be no fuel leaking from the acceleration port, any adjusting screw seals, or from mating joints – at any time. If fuel leakage rates in the input drive shaft cavity or out of the drain port exceed one drop in 5 minutes, reject the unit.

d. General Test Instructions

(1) Testing sequences, input and output limits, and run parameters are contained in Table 8. Refer to Table 8 for all references to data point values.

For each operating sequence the input parameters shall be applied to the fuel control unit in the following order: fuel inlet pressure, input driveshaft speed, inlet air pressure.

(2) All testing operations shall be accomplished sequentially in the numerical order they appear within the testing instructions. It is not necessary to de-energize the fuel control unit between testing sequences. If a test section needs to be repeated, start at the previous sections final condition.

(3) All references to pump discharge pressure shall be interpreted to apply to those pressures coming out of the governor section of the fuel control unit. All references to nozzle discharge pressure shall be interpreted to apply to those pressures coming out of the electric solenoid.

(4) The electric solenoid is a normally closed device. Apply 24 to 28 Vdc to open, or energize, the solenoid. See Figure 25, Detail A for solenoid wiring diagram.

(5) For all testing sequences, the fuel discharge pressure shall be the sum of the nozzle back pressure curve and additional pressure equal to the air pressure applied to the acceleration limiter valve. This may be accomplished via an air controlled regulator connected to the air input and situated after the nozzle discharge simulator or by adding additional back pressure equal to air input to the back pressure curve at each testing sequence.

e. Test Procedures

Maintain a complete and accurate record of test run. Table 8, or equivalent automated test sheet, may be used for documentation.

(1) Air Leakage Check, Acceleration Limiter Valve

a. Install a pressure gage, with a minimum range of 0 to 60 psig, onto the acceleration limiter drain port. Apply detergent compound (43-34) to all areas where air pressure is contained.

Adjust the input parameters to the settings specified in data point 1.a. If any increasing pressure is read on the gage at the drain port or if any air leaks are detected with the detergent compound, reject the unit. Upon completion, remove the pressure gage and wipe off residual detergent.

WARNING

When disconnecting fuel lines between the fuel control unit and test stand always break connection at the side furthest away from the flow source. Ensure free end of fuel line is pointed in a safe direction before running fuel control unit.

(2) Purging Run (Priming Operation)

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a. Disconnect test stand end of the fuel line attached between the governor cap and the test stand. Point free end of fuel line in a safe direction and adjust the input parameters to the settings specified in data point 2.a.

1. Run unit for the time allotted then proceed to data point 2.b. After the fuel flowing through the line begins to discharge in a steady stream reduce driveshaft speed to zero rpm then reduce the fuel inlet pressure to zero psig. Reconnect the free end of the fuel line back onto the test stand and proceed to paragraph 10.e.3.

Run-In Schedule (Pump Break-In) is required only when bushings, gears, or housings have been replaced.

CAUTION

Open nozzle bypass valve before each increase in input driveshaft speed to prevent over-pressurization and damage to the fuel control unit.

(3) Run-In Schedule (Pump Break-In)

a. Remove the filter cap (Figure 22, 12) and filter element (Figure 22, 14) from the fuel control unit. Install filter plug assembly (288276-1) and filter plug cover (288277-1) to fuel control unit.

Disconnect fuel-out line from outlet port on fuel solenoid valve and connect to outlet port on filter plug cover. Install cap on solenoid valve to prevent unintentional discharge.

b. The nozzle discharge pressure shall be adjusted via the nozzle bypass valve. Sequentially operate the fuel control unit at each data point, 3.a through 3.f. If the fuel flow is less than the required value for data point 3.e, reject the unit.

c. Decrease input driveshaft speed and inlet air pressure to zero. Decrease fuel inlet pressure to zero psig. Open nozzle bypass valve. Remove previously installed cap from solenoid valve.

Remove fuel line from outlet port on filter plug cover and reinstall on solenoid valve. Remove filter plug assembly and filter plug cover. Reinstall filter element (14) and filter cap (12). Torque filter cap (12) to 100-110 inch-pounds.

(4) Acceleration Limiter Valve Cracking Pressure/ Crack Pressure Sensitivity

a. Disconnect air line from acceleration limiter and leave acceleration limiter port uncapped.

b. Beginning with the fuel solenoid valve in the closed position, adjust the input parameters to the settings specified in data point 4.a. Cycle (energize/de-energize) solenoid and measure pump discharge pressure. Loosen nut (Figure 21, 22) and adjust the acceleration limiter adjusting screw (Figure 21, 29) to obtain the fuel nozzle pressure (crack pressure) specified.

Tighten nut (22). Recheck two times by cycling (energize/de-energize) fuel solenoid valve twice.

c. If cracking pressure is unstable, loosen screws (Figure 21, 24), tap acceleration limiter cover

(27) gently until pressure stabilizes. Tighten screws (24) and recheck cracking pressure sensitivity.

d. Sequentially operate the fuel control unit at each subsequent data point within this step. For each fuel inlet pressure setting recheck the crack pressure two times by cycling fuel solenoid valve twice. Ensure the maximum difference between pump discharge pressures for all data points is within limits. Reject the unit if it is unable to reliably meet data point requirements.

e. Reconnect airline to acceleration limiter.

(5) Governor Set Point

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a. Adjust the input parameters to the settings specified in data point 5.a. Adjust the governor adjustment screw, as necessary, to obtain the required fuel flow.

(6) Speed Droop and Hysteresis

NOTE:

Steps requiring adjustment of RPM to achieve specified fuel flow parameters must adjust the RPM to reach max flow point, and continue increasing RPM to achieve specified fuel flow.

a. Adjust the input parameters to the settings specified in data point 6.a.

b. Decrease speed to obtain fuel flow rates as specified in data points 6.b and 6.c; record data at each point.

c. Increase speed to obtain fuel flow rates as specified in data points 6.d and 6.e; record data at each point.

d. Calculate speed droop and hysteresis as instructed.

e. If delta rpm is not within limits, use spring (Figure 23, Sheet 2, 75) with higher pound per inch rate to increase delta rpm or use lower pound per inch rate spring to decrease delta rpm. If spring is replaced, re-perform paragraph 10.e.5 “Governor Set Point”.

(7) Fuel Flow

a. Sequentially operate the fuel control unit at the input parameters listed in data points 7.a through 7.c. Record all data and check condition of solenoid by taking the difference between pump discharge and nozzle discharge pressures, as instructed. Reject the unit if it is unable to meet data point requirements for fuel flow.

(8) Pump Performance

a. Set the fuel control unit to the operating parameters listed in data point 8.a. The nozzle discharge pressure shall be adjusted via the nozzle bypass valve.

b. If the fuel flow is less than that specified in data point 8.a.

1. Check the pressure drop across the fuel solenoid valve. If the pressure drop exceeds 52 psid, reject the fuel solenoid valve.

CAUTION

Extreme care should be exercised when loosening each of the four housing nuts and adjusting the fuel pump. Only do so slowly and cautiously to avoid sudden or excessive leakage at the joint between the housings, which may cause damage to the gasket.

2. If the fuel solenoid valve is within limits, the fuel pump can be realigned as follows.

With the fuel control operating between 500 and 800 rpm, fuel inlet pressure and inlet air pressure per data point 8.a, and the pump discharge pressure between 55 and 65 psig. Loosen each of the four housing nuts (Figure 14, 94) approximately 1/8 to 1/4 turn. Adjust the fuel pump housing (Figure 14, 101) to obtain an increase in pump capacity (a very light tapping on the pump housing may be necessary to help seat the pump components). Torque the nuts to 30 to 40 inch-pounds and then recheck the flow per data point 8.a. Repeat this step if necessary.

c. Reject the unit if it is unable to meet data point requirements.

d. Open nozzle bypass valve.

(9) Repeatability and Nozzle Pressure Fluctuation

NOTE:

Steps requiring adjustment of RPM to achieve specified fuel flow parameters must adjust the RPM to reach max flow point, and continue increasing RPM to achieve specified fuel flow.

a. Sequentially operate the fuel control unit at the input parameters listed in data points 9.a through 9.f. Record all data. Check repeatability and nozzle pressure fluctuations as instructed.

Reject the unit if it is unable to meet data point requirements.

(10) Acceleration Limiter Valve Cracking Pressure – Recheck

a. Beginning with the fuel solenoid valve in the closed position, set the fuel control unit to the operating parameters listed in data point 10.a. Recheck crack pressure two times by cycling (energize/de-energize) fuel solenoid valve twice. If necessary, reset crack pressure as required and repeat this step.

b. Lockwire screws (Figure 21, 24) using lockwire (43-51). Repeat Step 10.e.10.a after acceleration limiter valve has been lockwired. Reject the unit if it is unable to meet the data point requirements.

(11) Final Governor Set Point

a. Set the fuel control unit to the operating parameters listed in data point 11.a. If necessary, readjust governor set point as required and repeat this step.

b. Lockwire nut (Figure 18, 48) using lockwire (43-51). Step 10.e.11.a shall be performed after governor has been lockwired. Reject the unit if it is unable to meet the data point requirements.

(12) Input Shaft Seal Leakage Check

a. Set the fuel control unit to the operating parameters listed in data point 12.a. The leakage rate from the fuel control input drive shaft seal into the drain cavity shall not exceed one drop.

(13) Fuel Filter Inspection and Leak Check

a. Adjust all inputs to zero.

b. Remove and inspect fuel filter.

c. If evidence of foreign particles is found, install a new filter; otherwise, reinstall the original element.

f. Preservation

(1) Adjust input drive shaft speed to zero.

(2) Adjust inlet air and fuel inlet pressures to zero.

(3) Shut off fuel, air and electrical power supplies.

(4) Disconnect electrical connector from fuel solenoid valve.

(5) Provide a suitable drain container.

(6) Disconnect fuel lines from fuel control unit. Drain line into drain container.

(7) Disconnect air lines to fuel control unit.

(8) Perform Preservation in accordance with paragraph 12.

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g. Post Test

(1) Lockwire filter cap (Figure 22, 12), plugs (16 and 20), screws (Figure 18, 50), and screws (Figure 21, 24) using lockwire (43-51).

(2) Remove fuel control unit from test setup. Drain fluids into drain container.

Do not use tape to cover openings

(3) Install protector cover over drive shaft (Figure 22, 3) or flex coupling (4) and secure to unit.

(4) Plug all openings and place fuel control unit in a dust and waterproof container.

TO 2G‐GTCP85‐43‐9

WP 006 00 OO‐MAN‐2015‐00150

Results

T.O.

Paragraph Number

Required Actual Required Actual Required Actual Required Actual Required Actual Required Actual

10.e.1 1 a Close 5 ± 1 50 ± 1 PASS / FAIL a Close Close 1/2 ± 1/4 20 ± 5 0 0 b Close Close 20 ± 5 800 ± 50 0 a 10 ± 1 15 ± 1 500 ± 100 0 25 ± 10 Record b 5 ± 1 15 ± 1 1500 ± 100 0 65 ± 25 Record c 5 ± 1 15 ± 1 2500 ± 100 0 165 ± 25 Record d 5 ± 1 15 ± 1 3500 ± 100 0 275 ± 25 Record e 15 ± 1 3930 ± 10 0 300 ± 10 ≥ 560 f ≥ 3 15 ± 1 4200 ± 10 0 500 ± 10 a Open/Close Close 5 ± 1 860 ± 10 0 60 ± 3 0 b Open/Close Close 1 +1/ ‐0 860 ± 10 0 60 ± 3 0 c Open/Close Close 10 ± 1 860 ± 10 0 60 ± 3 0 d Open/Close Close 15 ± 1 860 ± 10 0 60 ± 3 0 e Open/Close Close 20 ± 1 860 ± 10 0 60 ± 3 0 f 4 (max)

10.e.5 5 a Open Close 5 ± 1 5 ± 1 4260 ± 5 35 ± 1 Record 135 ± 2 PASS / FAIL a Open Close 5 ± 1 Record 35 ± 1 Record 70 ± 5 b Open Close 5 ± 1 Record 35 ± 1 Record 115 ± 2 c Open Close 5 ± 1 Record 35 ± 1 Record 295 ± 2 d Open Close 5 ± 1 Record 35 ± 1 Record 135 ± 2 e Open Close 5 ± 1 Record 35 ± 1 Record 115 ± 2 f 77‐103 g 20 max

SN: Date: Operator:

For each testing sequence circle the applicable result.

PASS / FAIL

PASS / FAIL

PASS / FAIL

PASS / FAIL

Pump Discharge Pressure (psig)

Table 8 ‐ Testing Operation(s) and Data Point(s)

Outputs

Test Sequence

Purging Run (Priming Operation)

Air Leakage Check, Acceleration Limiter Valve

InputsMachine Settings and DurationPart Number, Fuel Control Unit:

Applicable T.O.(s): Fuel Flow Rate (pph)

Inlet Air Pressure (Acceleration Limiter

Valve, Air Inlet) Time

Required (minutes)

Solenoid Position

(open/close)

Nozzle/ Atomizer

Bypass Valve (open/close)

Data Point

Nozzle Discharge Pressure (Back

Pressure)

10.e.2 2

10.e.6

Input Driveshaft Speed

(RPM)

Fuel Inlet Pressure (psig)

10.e.4

Run‐in Schedule (Pump break‐in)

Acceleration Limiter Valve Cracking Pressure/ Crack Pressure Sensitivity

Maximum difference between data points: 4.a through 4.e

10.e.3

Adjustable

(Used to adjust nozzle discharge pressure)

Close3

Governor Set Point

Speed Droop and Hysteresis

3609150‐8

2G‐GTCP85‐43‐9

Record Speed Droop (6.b minus 6.c)

Record Hysteresis (6.b minus 6.e)

TO 2G‐GTCP85‐43‐9

WP 006 00 OO‐MAN‐2015‐00150

Results

T.O.

Paragraph Number

Required Actual Required Actual Required Actual Required Actual Required Actual Required Actual

Maximum a Open Close 5 ± 1 4130 ± 5 35 ± 1 Record (7.a.1)

Record (7.a.2)

Record

Pump discharge minus nozzle discharge pressure (applies to data point 7.a) b P.dis ‐ P.noz (7.a.2 ‐ 7.a.1)

Minimum c Open Close 5 ± 1 4390 ± 5 35 ± 1 Record 50 max

10.e.8 8 a Open

Adjustable (Used to adjust nozzle discharge pressure)

5 ± 1 3905 ± 5 35 ± 1 300 ± 10 510 min PASS / FAIL

Set‐Point a Open Close 1/2 ± 1/4 5 ± 1 Record 35 ± 1 Record 135 ± 2

Speed Decrease b Open Close 5 ± 1 3930 ± 5 35 ± 1 Record

Return to Set‐Point c Open Close 5 ± 1 Record 35 ± 1 Record 135 ± 2

Ramp Down d Open Open 5 ± 1 0 0 0 0

Shutdown e Open Open 0 0 0 0 0

Repeatability Check f Open Close 5 ± 1 Record 35 ± 1 Record 135 ± 2

Maximum difference between data points: 9.a, 9.c, and 9.f g 10 max 30 max

10.e.10 10 a Open/Close Close 5 ± 1 860 ± 10 0 60 ± 3 0 PASS / FAIL

10.e.11 11 a Open Close 5 ± 1 4260 ± 5 35 ± 1 Record 135 ± 2 PASS / FAIL

10.e.12 12 a Close Close 5 +1/ ‐0 1 +1/ ‐0 4260 ± 5 35 ± 1 PASS / FAIL

Acceleration Limiter Valve Cracking Pressure ‐ Recheck

Final Governor Set Point

Input Shaft Seal Leakage Check

10.e.7 Fuel Flow 7 PASS / FAIL

Pump Performance

10.e.9

Repeatability and N ozzle Pressure

Fluctuation

9 PASS / FAIL

Input Driveshaft Speed

(RPM)

Inlet Air Pressure (Acceleration Limiter

Valve, Air Inlet)

Nozzle Discharge Pressure (Back

Pressure)

Pump Discharge Pressure (psig)

Fuel Flow Rate (pph)

For each testing sequence circle the applicable result.

Applicable T.O.(s): 2G‐GTCP85‐43‐9 Solenoid Position

(open/close)

Nozzle/ Atomizer

Bypass Valve (open/close)

Time Required (minutes)

Fuel Inlet Pressure (psig)

Test Sequence Data Point

Table 8 (continued)‐ Testing Operation(s) and Data Point(s) SN: Date: Operator:

Part Number, Fuel Control Unit: 3609150‐8 Machine Settings and Duration Inputs Outputs