Welding Neck Orifice Class 300SO Flanges
Slip On Orifice Flange
Slip-On Orifice Class 300
  Drilling
  Nom  Size OD Thickness OD of RF Dia at base Bore LTH Dia of Pressure Connection Bolt Circle Hole Dia # of holes Bolt Dia
O C R X B  Y TT        
in 1 4.88 1.50 2.00 2.12 1.36 1.88  1/4 3.50 0.69 4  5/8
mm   124.0 38.1 50.8 53.8 34.5 47.8 6.4 88.9 17.5   15.9
in 1 1/2 6.12 1.50 2.88 2.75 1.95 1.88  1/4 4.50 0.81 4  3/4
mm   155.4 38.1 73.2 69.9 49.5 47.8 6.4 114.3 20.6   19.1
in 2 6.50 1.50 3.62 3.31 2.44 1.94  1/4 5.00 0.69 8  5/8
mm   165.1 38.1 91.9 84.1 62.0 49.3 6.4 127.0 17.5   15.9
in 2 1/2 7.50 1.50 4.12 3.94 2.94 2.00  1/4 5.88 0.81 8  3/4
mm   190.5 38.1 104.6 100.1 74.7 50.8 6.4 149.4 20.6   19.1
in 3 8.25 1.50 5.00 4.62 3.57 2.06  3/8 6.62 0.81 8  3/4
mm   209.6 38.1 127.0 117.3 90.7 52.3 9.5 168.1 20.6   19.1
in 4 10.00 1.50 6.19 5.75 4.57 2.12  1/2 7.88 0.81 8  3/4
mm   254.0 38.1 157.2 146.1 116.1 53.8 12.7 200.2 20.6   19.1
in 6 12.50 1.50 8.50 8.12 6.72 2.12  1/2 10.62 0.88 12  3/4
mm   317.5 38.1 215.9 206.2 170.7 53.8 12.7 269.7 22.4   19.1
in 8 15.00 1.62 10.62 10.25 8.72 2.44  1/2 13.00 1.00 12  7/8
mm   381.0 41.1 269.7 260.4 221.5 62.0 12.7 330.2 25.4   22.2
in 10 17.50 1.88 12.75 12.62 10.88 2.62  1/2 15.25 1.12 16 1   
mm   444.5 47.8 323.9 320.5 276.4 66.5 12.7 387.4 28.4   25.4
in 12 20.50 2.00 15.00 14.75 12.88 2.88  1/2 17.75 1.25 16 1 1/8
mm   520.7 50.8 381.0 374.7 327.2 73.2 12.7 450.9 31.8   28.6
in 14 23.00 2.12 16.25 16.75 14.14 3.00  1/2 20.25 1.25 20 1 1/8
mm   584.2 53.8 412.8 425.5 359.2 76.2 12.7 514.4 31.8   28.6
in 16 25.50 2.25 18.50 19.00 16.16 3.25  1/2 22.50 1.38 20 1 1/4
mm   647.7 57.2 469.9 482.6 410.5 82.6 12.7 571.5 35.1   31.8
in 18 28.00 2.38 21.00 21.00 18.18 3.50  1/2 24.75 1.38 24 1 1/4
mm   711.2 60.5 533.4 533.4 461.8 88.9 12.7 628.7 35.1   31.8
in 20 30.50 2.50 23.00 23.12 20.20 3.75  1/2 27.00 1.38 24 1 1/4
mm   774.7 63.5 584.2 587.2 513.1 95.3 12.7 685.8 35.1   31.8
in 24 36.00 2.75 27.25 27.62 24.25 4.19  1/2 32.00 1.62 24 1 1/2
mm   914.4 69.9 692.2 701.5 616.0 106.4 12.7 812.8 41.1   38.1
1.  Other NPT and SW connections available upon request.

Welding Neck Orifice Class 300SO Flange PDF (for printing).