Nozzle_Waterflow_Testing_Procedures.pdf

8-389. WATER FLOW INSPECTION OF HIGH PRESSURE TURBINE STAGE 1 AND STAGE 2

NOZZLES.

(See Figures 8-629 and 8-630.) Water flow check the cooling air holes and passages for blockage:

a. Water flow inspect stage 1 nozzles as follows: (See Figure 8-629.)

S9234-AB-MMD-020

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Figure 8-629. Water Flow Inspection of High Pressure Turbine Stage 1 Nozzles

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1. Set-up water flow fixture. P/N 1C8130, preferably in a sink, with a splash panel in the back. Connect fix-ture to a filtered water supply with a pressure regulator in the line that will regulate water pressure in the range of 10-30 psi.

The following P numbers are from stage 1 nozzle water flow test fixture, P/N 1C8130.

2. On twin shank turbine configuration, install inner and outer platform gaskets as follows:

(a) Install inner gasket (P13) into fixture.

(b) Install outer gasket (P15) into fixture. When testing borescope nozzle segment install outer gasket (P14) into fixture. Ensure gasket is positioned to accept nozzle segment forward side down.

3. On single shank turbine configuration, install inner and outer platform gaskets as follows:

(a) Install inner gasket (P16) into fixture.

(b) Install outer gasket (P17) into fixture. When testing borescope nozzle segment install outer gasket (P18) into fixture. Ensure gasket is positioned to accept nozzle segment forward side down.

4. Install stage 1 nozzle segment, forward side up, into gaskets and lock clamping handle.

5. Water flow inspect both vanes through nose/gill and trailing edge by use of the four valve handles. Refer-ence Figure 8-629 to identify which handle opens which water circuit. A tilt arm is provided for tilting nozzle segment to obtain best position for observing flow.

6. Proceed to Step c.

b. Water flow inspect stage 2 nozzles as follows: (See Figure 8-630.)

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Figure 8-630. Water Flow Inspection of High Pressure Turbine Stage 2 Nozzles

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1. Set-up water flow fixture, P/N 1C8174, same as instructed in Step a.1 above.

Mount that retains seals is adjustable to obtain best fit between seals and nozzle platform.

The following P numbers are from stage 2 nozzle water flow test fixture, P/N 1C8174.

2. Install inner platform gasket as follows:

(a) On twin shank turbine configuration, install inner platform gasket (P10) into fixture.

(b) On single shank turbine configuration, install inner platform gaskets (P09) into fixture.

3. Install stage 2 nozzle segment, forward side down, into fixture, aligning fixture seals into nozzle segment outer platform bosses. Check for proper seating between nozzle segment, gasket and seals. Secure adjust-able mount and lock clamping handle.

4. Water flow inspect both vanes through trailing edge holes by use of two valve handles. See Figure 8-630 to identify which handle opens which water circuit.

5. Proceed to Step c.

c. For stage 1 vanes, visually inspect to assure water flows freely from nose, gill and trailing edge holes. For stage 2 vanes, visually inspect to assure water flows freely from vane trailing edge holes. If blocked, dribbling or bubbling holes are detected during inspection, attempt to open holes by carefully inserting a 0.015 inch ″piano type″ wire, (available from Malin’s, 2514 Vestry Ave., Cleveland, OH, or equivalent) in a hand hold-ing pin vise, into holes. Do not use excessive force that will result in wire becoming lodged in, or broken off, in hole. Reference Table 8-136 and 8-137 for limits established for blocked holes.

A free flowing hole is one that flows a steady stream without dribbling or bub-bling out.

d. Remove vane segments from holding fixture. Insert an air nozzle into holes at both ends of each vane and blow water out of vanes using air pressure 20-40 psig.

e. Vanes with blockage beyond serviceable limits shall be recleaned per Table 3-1 and water flow inspected again. Vanes failing second water flow inspection shall be replaced.

8-390. HIGH PRESSURE TURBINE ROTOR.

8-391. GENERAL.

Although no maximum turbine rotor operating time has been established, it is essential to maintain accurate records on all rotors and their component parts. In addition to the normal fluorescent-penetrant, visual and dimensional inspections that are performed to establish serviceability, if overtemperature is suspected, perform a Rockwell Hardness test on the designated areas of the turbine shaft, stage 1 and 2 rotor disks and rear shaft. Refer to the respective inspection table for specified limits. A portable hardness tester, Model MR, National Sales and Services, Newage Industries, Inc., 815 Greenwood Ave., Jenkintown, PA, or equivalent may be used for this test.

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