Welding Neck Orifice Class 300 Threaded Flanges
Threaded Orifice Flange
Threaded Orifice Class 300
  Drilling
Nom Size OD Thickness OD of RF Dia at Base LTH OD of Counter Bore Counter Bore Depth         (from face) Dia of    Pressure Connection Bolt Circle Hole Dia # of Holes Bolt Dia
  O C R X Y Qb (2) Qf (3) F G TT        
in. 1 4.88 1.50 2.00 2.12 1.88 1.41 1.30 1.44 0.75  1/4 3.50 0.69 4     5/8
mm.   124.0 38.1 50.8 53.8 47.8 35.8 33.0 36.6 19.1 6.4 88.9 17.5   15.9
in. 1 1/2 6.12 1.50 2.88 2.75 1.88 1.99 1.89 1.47 0.72  1/4 4.50 0.81 4     3/4
mm.   155.4 38.1 73.2 69.9 47.8 50.5 48.0 37.3 18.3 6.4 114.3 20.6   19.1
in. 2 6.50 1.50 3.62 3.31 1.94 2.50 2.36 1.50 0.69  1/4 5.00 0.69 8     5/8
mm.   165.1 38.1 91.9 84.1 49.3 63.5 59.9 38.1 17.5 6.4 127.0 17.5   15.9
in. 2 1/2 7.50 1.50 4.12 3.94 2.00 3.00 2.84 1.75 0.56  1/4 5.88 0.81 8     3/4
mm.   190.5 38.1 104.6 100.1 50.8 76.2 72.1 44.5 14.2 6.4 149.4 20.6   19.1
in. 3 8.25 1.50 5.00 4.62 2.06 3.63 3.46 1.81 0.56  3/8 6.62 0.81 8     3/4
mm.   209.6 38.1 127.0 117.3 52.3 92.2 87.9 46.0 14.2 9.5 168.1 20.6   19.1
in. 4 10.00 1.50 6.19 5.75 2.12 4.63 4.45 1.88 0.56  1/2 7.88 0.81 8     3/4
mm.   254.0 38.1 157.2 146.1 53.8 117.6 113.0 47.8 14.2 12.7 200.2 20.6   19.1
in. 6 12.50 1.50 8.50 8.12 2.12 6.75 6.57 1.88 0.31  1/2 10.62 0.88 12     3/4
mm.   317.5 38.1 215.9 206.2 53.8 171.5 166.9 47.8 7.9 12.7 269.7 22.4   19.1
in. 8 15.00 1.62 10.62 10.25 2.44 8.75 8.55 2.19 0.44  1/2 13.00 1.00 12     7/8
mm.   381.0 41.1 269.7 260.4 62.0 222.3 217.2 55.6 11.2 12.7 330.2 25.4   22.2
(1) Other NPT and SW connections available upon request.
(2) Qb counterbore back.
(3) Qf counterbore face.

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