A-10_FuelControl__TestInstruction.pdf.pdf

T.O. 2G-GTCP36-12

WP 012 00

APPLICABLE SUPPORT EQUIPMENT

Tool No. Nomenclature Item/Figure No.

25-241 Dial Indicator -- 281600-4-1 Test Stand Assembly, Fuel Accessories 1/T1 Alt Stands (Part No. 281600-7-1/2816007-1-P1) 102187-59-1 Adapter Assembly 1A/Not Shown 294240-3 Lapping Tool, Hand (Lapping Tool) 2/T1 296421-1 Guide, Seal Installation (Guide) 3/T1 296501-1 Adapter (Alt Part No. 102187-59-1) 4/T1 296502-1 Plug, Delta P Valve (Valve Plug) 5/T1 296503-1 Plug, Relief Valve (Valve Plug) 6/T1 296504-1 Cover, Torque Motor (Cover) 7/T1 296505-1 Adapter, Fuel Nozzle (Adapter) 8/T1 296506-1 Controller, Torque Motor (Controller) 9/T1 296507-1 Fixture, Adjusting Torque Motor (Fixture) 10/T1 296530-1 Plug, Filter Element (Plug) 11/T1 296691-1 Test Fixture, Torque Motor (Test Fixture) 12/T1 201125304 Slide Hammer Torque Motor Adjustment Tool 13/T1

APPLICABLE TCTOS

None

REFERENCE MATERIAL REQUIRED

Aircraft Electric and Electronic Wiring T.O. 1-1A-14 Cleaning of Gas Turbine Engine and Parts T.O. 2J-1-13 Corrosion Prevention and Control for Aerospace Equipment T.O. 1-1-691 General Cleaning Procedures WP 003 00 This Manual General Information WP 002 00 This Manual Methods of Preservation – Final Packaging MIL-P-116 Nondestructive Inspection Methods T.O. 33B-1-1

CONSUMABLE MATERIALS

NOTE

Index numbers are for reference to master consumable list in WP 002 00.

All references to consumables in text will be preceded by 12.

(Example: Oil (12-54))

Index No. Nomenclature 1 Abrasive Paper (400 and 600 Grit) (Federal Specification P-P-101) 15A Assembly Fluid (Royco HF-825 Acryloid) 30 Compound (Specification MIL-S-22473, Grade AVV) 53 Oil (Specification MIL-L-6081) 54 Oil (Specification MIL-L-7808 or Specification MIL-L-23699) 79 Solvent, Dry Cleaning (Federal Specification P-D-680, Type II or III)

SWP 012 06

1. TESTING.

a. Torque Motor Testing.

NOTE

This test is necessary when testing a used torque motor or if a new torque motor is suspect of discrepancy.

(1) Record data as required on data sheet, Table 1.

(2) Perform case ground continuity check.

(a) Measure resistance between pin 5 and connector shell.

(b) A resistance reading shall indicate a closed circuit (continuity).

(3) Perform insulation resistance test.

(a) Apply 500 Vdc between pins 1 or 3 and pin 5 (case ground).

(b) Minimum resistance shall be 100 mega-ohms.

(4) Perform functional test of torque motor.

(a) Apply assembly fluid (46-18) to packing (SWP 012 01, figure 1, 6).

(b) Install torque motor (figure 2, 12), packing (SWP 012 01, figure 1, 6), screws (3 & 3A), & washers (4).

into test fixture, P/N 296691-1 (Figure 1, 3). Torque screws (3 & 3A) to 45-50 inch-pounds.

(c) Assemble and setup test equipment as shown in Figure 1.

(d) Proof-pressure test torque motor.

1 Set supply pressure at 825 psig (±5) for 1 minute.

2 There shall be no external leakage.

3 Reduce pressure to zero.

NOTE

To eliminate hysteresis effects, do not exceed the specified current value when the current is adjusted before the readings (data are noted. If necessary, adjust the current value to the last data print prior to setting at a specified value.

(e) Perform flow test.

1 Maintain the supply pressure at 175 (±25) psig.

2 Increase the torque motor current to the values shown on the data sheet (0 to 155 mA), Table 1.

NOTE

To eliminate hysteresis effects, do not exceed the specified current value when the current is adjusted before the readings (data are noted. If necessary, adjust the current value to the last data print prior to setting at a specified value.

3 Adjust the hand valve for ΔP = 25 (±0.5) psig.

4 Record the corresponding flow readings in the INCREASE column of the data sheet, Table 1.

5 Decrease the torque motor current from 155 mA to the current values shown on the data sheet, Table

1.

6 Record the flow readings in the DECREASE column.

(f) Perform hysteresis test.

1 Increase current to 70 mA and adjust the hand valve for a ΔP of 25 (±0.5) psid. Record the flow.

2 Increase the current to 155 mA, then decrease the current until the flow equals the recorded flow in step 1. Current shall be within 65.3 to 70 mA. Record on data sheet, Table 1.

Table 1 Fuel Control Motor Data Sheet

Check No. Test Required Accept Reject

1 Visual Inspection (√)

2 Insulation Resistance 100 MΩ

3 Case Ground Continuity Check Closed Circuit

4 Functional Test

4a Proof-Pressure

Input

Current

(mA)

ΔP

PSID

±0.5

Flow, lb/hr.

Required INC DEC

4b Flow Test 0

25 0-19

22-45

77-110

170-220

4c Hysteresis 70 Reference Flow __________

65.3-70 Record ____________

Remarks:

Figure 1 Test Setup for Torque Motor

b. Fuel Control Assembly Testing.

(1) Prepare fuel control assembly for testing. (See Figure 2)

(a) Remove fuel control torque motor (12) and high pressure filter. Install torque motor cover P/N 296504-1.

(b) Remove ultimate relief valve (7) components and install valve plug P/N 296503-1 (figure T1, 6).

(c) Remove differential pressure valve (2) components and install valve plug P/N 296502-1 (figure T1, 5).

(2) Install fuel control assembly in Pump Run-In/Pump Capacity Test Setup (Figure 3).

(a) Install adapter (1A) (P/N 102187-59-1) onto stand.

(b) Install fuel control assembly onto adapter (1A) using clamp, P/N 4268C316M, and packing, P/N S9413-

036, with filter bore in the downward position.

Lube oil may contain tricresyl phosphate. This additive is poisonous and can be readily absorbed through the skin. Make certain this oil does not remain on the skin. The oil may burn if exposed to heat or flames. Use only in a well-ventilated area. Neoprene gloves and face shield/safety goggles shall be worn when handling oil.

Rotation of drive gearshaft on fuel control assembly shall be counterclockwise when viewed from drive gearshaft end.

(c) Fill adapter (1A) with lubricating oil (46-54) and pressurize with 10 (±1) psig oil or air pressure.

(d) Make all fuel control assembly connections according to Figure 3.

(3) Pump Run-In Test

Pump run-in is only required when sleeve bearing assemblies spur gear-shaft, splined spur gearshaft, or fuel control body assembly have been replaced.

WARNING

Special care should be taken to prevent closing the back pressure valve off entirely while fuel control unit is in operation. Risk to personnel may occur without preventative measures built into the stand.

CAUTION

Open back pressure valve between steps to prevent pressure spikes which may damage the fuel control unit.

(a) Open back pressure valve (8).

(b) Set fuel control assembly inlet pressure to 15 (±1) psig as indicated on inlet pressure gage (4).

Pin

PD

(102187-59-1)

(296504-1)

(c) Refer to Table 3 for operational conditions for pump run-in test.

(d) Slowly increase pump pressure (PD) between each test point in Table 3 as indicated in on pump discharge pressure gage (7) by slowly closing back pressure valve (8).

Table 3 Pump Run-In Requirements

Speed (NP), RPM

Pump Inlet Pressure (Pin), psig

Pump Discharge

Pressure (PD), psig

Time (minutes)

±5 sec.

200 15 ±1 25 ± 5 2

200 15 ±1 50 ±5 2

200 15 ±1 75 ±5 2

750 15 ±1 25 ±5 1

750 15 ±1 50 ±5 1

750 15 ±1 100 ±5 2

750 15 ±1 200 ±5 2

1500 15 ±1 100 ±5 1

1500 15 ±1 200 ±5 2

1500 15 ±1 300 ±5 2

2200 15 ±1 200 ±5 2

2200 15 ±1 300 ±5 2

2200 15 ±1 400 ±5 2

2200 15 ±1 500 ±5 2

(4) Pump Capacity Check.

WARNING

Special care should be taken to prevent closing the back pressure valve off entirely while fuel control unit is in operation. Risk to personnel may occur without preventative measures built into the stand.

(a) Open back pressure valve (8).

(b) Set test parameters in accordance with condition 2 (Table 4) and in sequence, progressively check to ensure pump performs to requirements of condition 2(a), 2(b), and 2(c). Record flow WF. Pump

Discharge Pressure (PD) is controlled by slowly closing back pressure valve (8).

(c) If Fuel Flow (WF) does not meet minimum requirements, check for the following probable cause.

1 Loose or excessive clearance between bearings. Clearance shall not exceed 0.0002 inch.

2 Damaged seal on one of more bearings.

3 Excessive wear in fuel control body assembly.

4 If fuel pump does not meet minimum requirement or the probable cause cannot be corrected, reject fuel control.

(d) Open back pressure valve, set all test stand values to zero, then disconnect fuel lines from fuel control assembly.

(5) Fuel Control Assembly Calibration.

(a) Reconstruct test setup. See Figure 2 for connection points and Figure 4 for flow schematic.

1 Remove torque motor cover (figure T1, 7) P/N 296504-1.

2 Apply assembly fluid (46-18) to all packings (Figure 1, sheet 1, Items 5, 6, 7, 12) reinstall high pressure filter (11 & 12) and snap ring (10) and fuel control torque motor (5-9). Install washers (4) and screws (3, & 3A). Torque to 45-50 inch-pounds.

3 Remove ultimate relief valve plug (figure TI, 6) P/N 296503-1 if installed for pump run-in or capacity test and reinstall ultimate relief valve components (Figure 1. Sheet 3, 38-50). Torque screws

(38-39) to 28-32 inch-pounds.

4 Remove differential pressure valve plug (figure TI, 5) P/N 296502-1 if installed for pump run-in or capacity test and reinstall differential pressure valve components (Figure 1. Sheet 3, 51-61). Torque screws (51) to 45-50 inch-pounds.

5 Make all connections to fuel control assembly according to Figure 4.

6 Install fuel nozzle assembly (Figure 4, 8) P/N 3830061-2 into adapter (9), part No. 296505-1 or set up test stand to provide fuel back pressure in accordance with Table 5. Additional back pressure

(PBP) shall be created by regulator (13).

(b) Set controls and purge fuel control of air.

1 Open shutoff valve (Figure 4, 10).

2 Adjust air or oil pressure to 10 (±2) psig to adapter (Figure TI, 1A).

3 Adjust back pressure regulator (Figure 4, 13) to zero.

4 Set Fuel Inlet Pressure (Pin) to 25 (±1) psig.

5 Set pump speed to 400 rpm.

6 Run fuel control until all air is purged from system by checking a sight glass integrated in the system.

(c) Perform ultimate relief valve calibration. (See condition 3, Table 4.)

Do not exceed 575 psig pump discharge pressure (PD). Pressures exceeding 575 psig may cause damage to fuel control assembly.

1 Set test parameters in accordance with Table 4. Adjust Torque Motor Current (ITM) to obtain 200

±5 pph fuel flow (WF).

32 Gradually close shutoff valve (Figure 4, 10) and observe PD on pump discharge pressure gage (6).

Relief valve (11) will start to crack below the ultimate pressure. Ultimate pressure shall be 525 (±25) psig on pump discharge gage (6) when shutoff valve (10) is fully closed.

43 If pump discharge pressure (PD) is out of limits of Table 4, reshim ultimate relief valve.

(i) If pump discharge pressure (PD) is below 500 psig, increase thickness of special washers. An increase of 0.005 inch will increase pump discharge pressure (PD) approximately 10 psig.

(ii) If pump discharge pressure (PD) is above 550 psig, decrease thickness of special washers. A decrease of 0.005 inch will decrease pump discharge pressure (PD) approximately 10 psig.

(iii) Repeat ultimate relief valve calibration check in accordance with paragraph 6, step (c) until pump discharge pressure (PD) falls into limits of Table 4, condition 3 with shutoff valve (Figure

4, 10) fully closed.

54 Set all values on test stand to zero.

Figure 4 - Fuel Control Calibration Test Setup

(d) Filter Bypass Valve Leakage Check and Calibration.

1 Remove filter cover (Figure 2, 9) and filter assembly. Install plug (Figure TI, 11) P/N 296530-1.

Reinstall filter cover (figure 2, 9). Symmetrically torque screws (SWP 012 01, figure 1, 28) to 48-52 inch-pounds.

2 Remove pump inlet pressure plug (8) and connect a fuel line to measure fuel leakage through filter bypass valve. Opposite end of fuel line shall drain into test stand drain so operator can verify leakage.

3 Close shutoff valve (Figure 4, 10).

4 Purge System and fuel control unit of air by applying 20 psi of fuel to inlet port until filter bypass cracks and constant stream of fuel is observed.

5 Decrease fuel pressure to zero. .

6 Set test parameters in accordance with Table 4. Check for actuation on differential pressure indicator

(Figure 2, 3) before 6 psig.

7 Measure leakage from pump inlet pressure boss for one minute. Leakage shall not exceed 10 cubic centimeters per minute.

8 If leakage exceeds 10 cubic centimeters (10 mL) per minute, check rubber seal on poppet valve assembly for damage or add shim washer (SWP 012 05, figure 1, 35) as needed to meet requirement.

9 Connect fuel line from pump inlet pressure plug boss to test stand return fitting. (See Figure 4)

(e) Filter Bypass Valve (Minimum Flow) Procedure

1 Refer to table 4.

2 Set pump speed (NP) to zero rpm.

3 Increase fuel inlet pressure (Pin) until full-flow through filter bypass valve is obtained. Valve shall be in full-flow at fuel inlet pressure Pin of 10 ±1 psig with a WF of 35 pph minimum.

4 If full-flow (WF = 35 pph minimum) pressure setting (Pin) is not within limits, reshim filter bypass valve (Figure 2, 1) or replace spring (SWP 012 01, Figure 1, 36). A 0.010 change in thickness of special washers will change pressure setting approximately 2.0 psig. Increase thickness to increase pressure. Decrease thickness to decrease pressure setting of full-flow.

5 Set all values of test stand to zero.

6 Remove fuel line from pump inlet pressure plug boss and reinstall pump inlet pressure plug (Figure

2, 8).

7 Remove plug, P/N 296530-1, and reinstall filter assembly and filter cover (Figure 2, 9). Torque to

35±5 inch pounds??.

8 Reset differential pressure indicator (3).

(f) Differential Pressure Valve Check

1 Open shutoff valve (Figure 4, 10).

2 Set test parameters in accordance with Table 4.

3 Record WF and differential pressure (ΔP). Fuel flow (WF) and ΔP shall be within limits of Table 4.

4 If ΔP requirements are not met, check packings for damage and/or reshim differential pressure valve

(Figure 2, 2).

(i) Increase thickness of differential pressure valve shims to increase ΔP or decrease thickness of shims to decrease ΔP.

5 If flow (WF) requirements are not met, adjust torque motor post.

(i) Install fixture, P/N 296507-1 or 201125304.

Insert adjusting screw tool by hand. Do not force in.

Do not over adjust torque motor, damage may occur.

NOTE

The adjusting tool knurled wheel has built-in deadband from increasing to decreasing fuel direction. Care must be taken not to over-adjust the torque motor. A slight adjustment (±1 degree) is required to change fuel flow, therefore, always adjust the torque motor while observing fuel flow on the flow meter.

(ii) Screw adjusting screw by hand (do not force) into torque motor adjusting post between six to eight turns or until adjusting screw bottoms out. If it bottoms out, back out adjusting screw one turn. When using tool 201125304 slide hammer tool, carefully tap slide in or out to adjust torque motor to range specified in Table 4.

(iii) To increase WF push adjusting knurled wheel on fixture clockwise. To decrease WF pull adjusting knurled wheel counterclockwise.

(iv)(ii)

(v)(iii) Adjust torque motor post as required to meet conditions outlined in Table 4.

(vi)(iv) Record data.

(vii)(v) Remove fixture previously installed and reinstall torque motor post cap.

(g) Torque motor metering valve calibration performance check.

1 Ensure shutoff valve (Figure 4, 10) is fully open.

2 Set test parameters in accordance with conditions outlined in Table 4. In sequence, progressively check and record data from condition 6(a) through 6(h) by setting torque motor current (ITM).

Changes in WF shall be smooth.

3 With pump speed at 2070 rpm, vary torque motor current (ITM) from zero to 155 to zero mA at least

3 times. Changes in WF shall be smooth and metering valve shall be free from sticking. ΔP shall change slightly in the range of normal droop, without sharp changes in value.

4 If WF does not meet requirements or is not smooth (sticking metering valve or differential pressure valve), inspect differential valve. After inspection, if differential pressure valve meets inspection requirements, replace fuel control torque motor.

(i) Repeat torque motor calibration performance check, paragraph (g), after replacing components.

2. PRESERVATION.

a. If the fuel control unit is to be shipped as a spare part or stored for 10 days or more, the unit shall be preserved by disconnecting all fuel and air lines and providing drain lines.

b. Supply oil (12-53) to the fuel inlet port.

c. Drive the input shaft at a speed of 200 to 500 rpm until clear oil flows from the discharge fitting.

d. Drain all oil from the unit and plug all fittings; some residual oil is allowed.

e. When preparing for final shipment, preserve and package fuel control unit in accordance with Specification

MIL-P-116, Method III.

Table 4 Data Run Sheet.

Serial Number: ________________ Date: ___________________________

Description Inputs Measurements

Condition Para No. Test

Pump Inlet

Pressure

(Pin), psig

Pump

Speed

(NP),

±10 rpm

Fuel Back-Pressure

(PBP)*, psig

Torque Motor

Current (ITM), ±0.1 mA

Fuel Flow (WF), pph

Pump

Discharge

Pressure

(PD), psig

ΔP, psid

1 b.3 Pump Run-In See Table 3

2(a) b.4 Pump

Capacity

25 ±1 200 35 min 50 ±2

2(b) 25 ±1 750 170 min 100 ±2

2(c) 25 ±1 2200 500 min 400 ±2

3 b.5.c Ultimate

Relief Valve 25 ±1 2000 See Para 200 ±5 525 ±25

4(a) b.5.d

Filter Bypass

Valve

(Leakage)

See para, 6 max

0 10 cc/min

4(b) b.5.e

Filter Bypass

(Minimum

Flow)

10 ±1 0 35 min

5 b.5.f Differential

Pressure Valve 40 ±1 2070 40 0 28-33 25-35

6(a) b.5.g Torque Motor

Calibration

25 ±1 200 0 0 Record

6(b) 25 ±1 415 0 10 12-46

6(c) 25 ±1 620 0.5 20 20-60

6(d) 25 ±1 1035 8 50 53-100

6(e) 25 ±1 1680 37 100 104-175

6(f) 25 ±1 2070 40 150 155-250

6(g) 25 ±1 1035 8 50 +7, -2 of 6(d)

6(h) 25 ±1 2070 40 0 33 max

*This back pressure value is in addition to the back pressure created by the atomizer simulator (reference Table 5 for back pressure curve).