1900 Series - Maintenance Manual

XI. Maintenance (Contd.)Lapped Nozzle Seat WidthsA wide nozzle seat will induce simmer, especially in thesmaller-orifice, lower-pressure valves. For this reason,the seats of valves other than O-ring valves should beas narrow as is practical. Since the seat must be wideenough to carry the bearing load imposed upon it by thespring force, the higher-pressure valves must have widerseats than the lower-pressure valves. The nozzle seatwidth should conform to the measurements in Tables 7ato 7d.Table 7a: Nozzle Seat Width (Standard MetalSeat Design)Lapped SeatSet Pressure RangeOrificeWidthpsig barg in. mmD-G 1 – 50 0.07 – 3.45 .012 0.3051 – 100 3.52 – 6.89 .018 0.46101 – 250 6.96 – 17.24 .025 0.64251 – 400 17.31 – 27.58 .032 0.81401 – Above 27.65 – Above .038 0.97H-J 1 – 50 0.07 – 3.45 .019 0.4851 – 100 3.52 – 6.89 .025 0.64101 – 250 6.96 – 17.24 .029 0.74251 – 400 17.31 – 27.58 .032 0.81401 – 800 27.65 – 55.16 .038 0.97801 – Above 55.23 – Above .038 1 0.97 1K-N 1 – 50 0.07 – 3.45 .025 0.6451 – 100 3.52 – 6.89 .030 0.76101 – 250 6.96 – 17.24 .035 0.89251 – 400 17.31 – 27.58 .040 1.02401 – 800 27.65 – 55.16 .045 1.14801 – Above 55.23 – Above .045 1 1.14 1P-R 1 – 50 0.07 – 3.45 .030 0.7651 – 100 3.52 – 6.89 .037 0.94101 – 251 6.96 – 17.31 .045 1.14251 – 400 17.31 – 27.58 .052 1.32401 – 800 27.65 – 55.16 .059 1.50801 – Above 55.23 – Above .064 1.63T 1 – 50 0.07 – 3.45 .040 1.0251 – 100 3.52 – 6.89 .045 1.14101 – 250 6.96 – 17.24 .053 1.35251 – 300 17.31 – 20.68 .060 1.52U 1 – 50 0.07 – 3.45 .040 1.0251 – 100 3.52 – 6.89 .045 1.14101 – 250 6.96 – 17.24 .053 1.35251 – 300 17.31 – 20.68 .060 1.52V 1 – 50 0.07 – 3.45 .075 1.9151 – 100 3.52 – 6.89 .090 2.29101 – 250 6.96 – 17.24 .115 2.92251 – 300 17.31 – 20.68 .130 3.30W 1 – 50 0.07 – 3.45 .100 2.5451 – 100 3.52 – 6.89 .120 3.05101 – 250 6.96 – 17.24 .140 3.56251 – 300 17.31 – 20.68 .160 4.0632 | Dresser Consolidated ®Table 7b: Nozzle Seat Width (Standard Metal SeatDesign (UM) 2Lapped SeatSet Pressure RangeOrificeWidthpsig barg in. mmT-U 1 – 50 0.07 – 3.45 .040 1.0251 – 100 3.52 – 6.89 .045 1.14101 – 250 6.96 – 17.24 .053 1.35251 – 300 17.31 – 20.68 .060 1.52Note 2: All other values same as in Table 7a.Table 7c: Nozzle Seat Width (Thermodisc SeatDesign)Set Pressure Range Lapped Seat WidthOrificepsig barg in. mmD-F 1 – 100 0.07 – 6.89 .020 – .030 0.51 – 0.76101 – 300 6.96 – 20.68 .035 – .045 0.89 – 1.14301 – 800 20.75 – 55.16 .045 – .055 1.14 – 1.40801 – Above 55.23 – Above Full Width 3 Full Width 3G-J 1 – 100 0.07 – 6.89 .025 – .035 0.64 – 0.89101 – 300 6.96 – 20.68 .035 – .045 0.89 – 1.14301 – 800 20.75 – 55.16 .045 – .055 1.14 – 1.40801 – Above 55.23 – Above Full Width 3 Full Width 3K-N 1 – 100 0.07 – 6.89 .035 – .045 0.89 – 1.14101 – 300 6.96 – 20.68 .045 – .055 1.14 – 1.40301 – 800 20.75 – 55.16 .055 – .065 1.40 – 1.65801 – Above 55.23 – Above Full Width 3 Full Width 3P-R 1 – 100 0.07 – 6.89 .040 – .050 1.02 – 1.27101 – 130 6.96 – 8.96 .050 – .065 1.27 – 1.65131 – 800 9.03 – 55.16 .060 – .070 1.52 – 1.78801 – Above 55.23 – Above Full Width 3 Full Width 3T 1 – 100 0.07 – 6.89 .050 – .065 1.27 – 1.65101 – 300 6.96 – 20.68 .060 – .075 1.52 – 1.91U 1 – 100 0.07 – 6.89 .050 – .065 1.27 – 1.65101 – 300 6.96 – 20.68 .060 – .075 1.52 – 1.91101 – 300 6.96 – 20.68 .095 – .130 2.41 – 3.30W 1 – 100 0.07 – 6.89 .100 – .125 2.54 – 3.18101 – 300 6.96 – 20.68 .120 – .160 3.05 – 4.06Note 1: + .005" (0.13 mm) per 100 psig (6.89 barg)[.070"(1.78 mm) ± .005"(0.13) max]. Note 3: Not to exceed .070"(1.78 mm) ± .005"(0.13).