1511 Series - Maintenance Manual

XIII.B. Continued3. Clearance between the disc and upper ring/guide:Measure the I.D. of the guide and the O.D. of thedisc; subtract to find the cold clearance.The maximum clearance should not be greater thanthe value indicated in Table 5. Greater clearances canindicate wear and can generate alignment problemsand cause the valve not to reseat properly.OrificeminTable 5: Allowable Clearance BetweenUpper Adjusting Ring and Disc (Note 1)ClearancemaxDisc OutsideDiameterUpper AdjustingRing (InsideDiameter)in. mm in. mm in. mm in. mmH .007 0.18 .014 0.36 1.905 48.39 1.919 48.74J .007 0.18 .014 0.36 2.445 62.10 2.459 62.46K .006 0.15 .013 0.33 2.930 74.42 2.939 74.65L .007 0.18 .014 0.36 3.638 92.41 3.652 92.76M .007 0.18 .014 0.36 4.079 103.61 4.093 103.96N .012 0.30 .019 0.48 4.483 113.87 4.502 114.35P .008 0.20 .017 0.43 5.448 138.38 5.465 138.81Q .010 0.25 .019 0.48 7.137 181.28 7.156 181.76Note 1: Once clearance exceeds table values, further inspection is required for the disc and upper adjusting ring.4. Adjusting rings:If damage is present on the lower surface of the upperadjusting ring, or on the upper surfaces of the loweradjusting ring, the damaged part must be replaced.Thread damage may also be a cause for replacement,if it prevents adjustments when the valve is heated.5. Bushing Seat:Seat bushings are normally treated as part of thevalve body and should be machined when necessary,inside the valve body. (See Seat Bushing MachiningInstructions, Section XIV.B.) When the “E” dimensionis reduced by machining or lapping to the minimumgiven in Table 6b, the valve seat bushing should beremachined to the given dimension. The bushingseat can be remachined until the limiting Dimension“G” is reached as per Table 6a. See instructionsconcerning the “G” dimension in Table 6b.The bushing seat must be lapped to a mirror finishto determine if they are flat and free of nicks, cutsand scratches. (See Section XIV.C. for LappingInstructions.)GETable 6a: Seat BushingReplacement CriteriaG minOrificein.mmH .960 24.38J .960 24.38BCK 1.210 30.73FL 1.398 35.51M 1.398 35.51N 1.523 38.68P 1.773 45.03Figure 7: Bushing SeatQ 2.210 56.1316 | Dresser Consolidated ®