To avoid damaging the gasket surface when checking the valve
seat Inserts for looseness, do not hammer on the gasket surface.
Using a light, brass hammer, check for loose valve seat inserts by tapping on the head adjacent to the
valve seat. A loose valve seat insert will tend to move and bounce in the counterbore. Tighten or
replace loose valve seat inserts in accordance with paragraph 9-11.
Check the valve seat inserts for erosion, burning, pitting, and wear. Sufficient metal must remain so
that regrinding is confined to the seat insert only. Regrind the valve seats in accordance with
paragraph 9-9. Replace valve seat inserts in accordance with paragraph 9-11.
Check injector tip protrusion and seal seat pattern as follows (see Figure 9-1, Figure 9-6, and Figure 9-
Do not install packings on injectors when performing protrusion and seal seat checks.
Lightly coat the injector seal seat (18, Figure 9-1) with Prussian blue compound. Install the
injector and seal seat assembly in the well, and tighten the retaining screws to 11 to 13 pound-
feet (15 to 18 newton-meters).
Zero the indicator button of dial indicator of gage block 3376220 on the head surface, then index
the indicator button on the injector tip to measure the protrusion (Figure 9-6). Injector tip
protrusion shall be 0.090 to 0.110 inch (2.29 to 2.79 mm).
Remove the injector and injector seal seat, and check the blueing pattern. The pattern shall
show a blue band that is a minimum of 0.060 inch (1.5 mm) in width, and located approximately
0.469 inch (11.91 mm) from the head surface (Figure 9-7).
Correct the injector tip protrusion by replacing the injector seal seat or injector, or by replacing
both the injector seal seat and injector as required.
Correct the injector seal seat pattern by replacing the injector seal seat or injector, or by
replacing both the injector seal seat and injector as required.
Inspect the valve crosshead guides as follows (see Figure 9-8).
Inspect the crosshead guides for straightness. Guides should be straight and at right angles to
the milled surface of the head.
Using a micrometer, check the crosshead guides for wear (dimension B, Figure 9-8). At the
point of greatest wear, the guide shall be a minimum diameter of 0.432 inch (10.97 mm).
Replace worn or bent crosshead guides in accordance with paragraph 9-10.
Inspect the valve guides as follows (see Figure 9-8):
Visually inspect the valve guides for chips, cracks, burrs, and galling.
Using a small hole gage, check the valve guide inside diameter for wear and out-of-round
(dimension C, Figure 9-8). Maximum inside diameter shall be 0.4996 inch (12.690 mm).
Replace worn or damaged valve guides in accordance with paragraph 9-11.