CLASS 125 CAST IRON FLANGED FITTINGS DIMENSIONS CHART

Dimensions chart for straight fittings, reducing fittings and base elbows and tee of class 125 cast iron flanged fittings per ASME B16.1.

Flange and General Dimensions (inches)
NPS Flanges General
Dia. of
Flange		 Min. Thickness
of Flange		 Inside Dia.
of Fittings		 Wall
Thickness
1 4.25 0.44 1.00 0.31
1 1/4 4.62 0.50 1.25 0.31
1 1/2 5.00 0.56 1.50 0.31
2 6.00 0.62 2.00 0.31
2 1/2 7.00 0.69 2.50 0.31
3 7.50 0.75 3.00 0.38
3 1/2 8.50 0.81 3.50 0.44
4 9.00 0.94 4.00 0.50
5 10.00 0.94 5.00 0.50
6 11.00 1.00 6.00 0.56
8 13.50 1.12 8.00 0.62
10 16.00 1.19 10.00 0.75
12 19.00 1.25 12.00 0.81
14 21.00 1.38 14.00 0.88
16 23.50 1.44 16.00 1.00
18 25.00 1.56 18.00 1.06
20 27.50 1.69 20.00 1.12
24 32.00 1.88 24.00 1.25
30 38.75 2.12 30.00 1.44
36 46.00 2.38 36.00 1.62
42 53.00 2.62 42.00 1.81
48 59.50 2.75 48.00 2.00

Class 125 Straight Fittings Dimensions
Straight Fittings Dimensions (inches)
NPS A B C D E F
1 3.50 5.00 1.75 5.75 1.75 -
1 1/4 3.75 5.50 2.00 6.25 1.75 -
1 1/2 4.00 6.00 2.25 7.00 2.00 -
2 4.50 6.50 2.50 8.00 2.50 5.0
2 1/2 5.00 7.00 3.00 9.50 2.50 5.5
3 5.50 7.75 3.00 10.00 3.00 6.0
3 1/2 6.00 8.50 3.50 11.50 3.00 6.5
4 6.50 9.00 4.00 12.00 3.00 7.0
5 7.50 10.25 4.50 13.50 3.50 8.0
6 8.00 11.50 5.00 14.50 3.50 9.0
8 9.00 14.00 5.50 17.50 4.50 11.0
10 11.00 16.50 6.50 20.50 5.00 12.0
12 12.00 19.00 7.50 24.50 5.50 14.0
14 14.00 21.50 7.50 27.00 6.00 16.0
16 15.00 24.00 8.00 30.00 6.50 18.0
18 16.50 26.50 8.50 32.00 7.00 19.0
20 18.00 29.00 9.50 35.00 8.00 20.0
24 22.00 34.00 11.00 40.50 9.00 24.0
30 25.00 41.50 15.00 49.00 10.00 30.0
36 28.00 49.00 18.00 - - 36.0
42 31.00 56.50 21.00 - - 42.0
48 34.00 64.00 24.00 - - 48.0

Notes:

NPS - Nominal Pipe Size,
A - Center to Face 90 deg. Elbow, Tees, Crosses, True Y, and Double-Branch Elbow,
B- Center to-Face 90 deg. Long Radius Elbow,
C - Center to Face 45 deg. elbow
D - Center to Face Lateral D
E - Short Center to Face True Y and Lateral E
F - Face to Face Reducer

Class 125 Reducing Fittings Dimensions
Reducing Fittings Dimensions (inches)
NPS Reducing Fittings
Tees and Crosses Laterals
NPS
Size
of
Outlet
and
Smaller		 H J NPS
Size
of
Branch
and
Smaller		 M N P
1 All reducing tees and crossed NPS 16 and smaller shall have the same center to face dimensions as straight size fittings, corresponding to size of the largest opening. All reducing leterals NPS 16 and smaller shall have the same center to face dimensions as straight size fittings, corresponding to size of the largest opening.
1 1/4
1 1/2
2
2 1/2
3
3 1/2
4
5
6
8
10
12
14
16
18 12.0 13.0 15.5 8 25.0 1.0 27.5
20 14.0 14.0 17.0 10 27.0 1.0 29.5
24 16.0 15.0 19.0 12 31.5 0.5 34.5
30 20.0 18.0 23.0 14 39.0 0.0 42.0
36 24.0 20.0 26.0 - - - -
42 24.0 23.0 30.0 - - - -
48 30.0 26.0 34.0 - - - -

Notes:

NPS - Nominal Pipe Size,
H - Center to Face Run
J- Center to Face Outlet or Side Outlet
M - Center to Face Run
N - Center to Face Run
P - Center to Face Branch


Class 125 Base Elbows Tees Fittings Dimensions
Base Elbows and Tees Dimensions (inches)
NPS R S T U NPS
Size of
Supporting
Pipe for
Base 		 Base Drilling
W Dia.
of
Holes
1 3.50 3.50 0.44 0.38 3/4 2.75 0.62
1 1/4 3.62 3.50 0.44 0.38 3/4 2.75 0.62
1 1/2 3.75 4.25 0.44 0.50 1 3.12 0.62
2 4.12 4.62 0.50 0.50 1 1/4 3.50 0.62
2 1/2 4.50 4.62 0.50 0.50 1 1/4 3.50 0.62
3 4.88 5.00 0.56 0.50 1 1/2 3.88 0.62
3 1/2 5.25 5.00 0.56 0.50 1 1/2 3.88 0.62
4 5.50 6.00 0.62 0.50 2 4.25 0.75
5 6.25 7.00 0.69 0.62 2 1/2 5.50 0.75
6 7.00 7.00 0.69 0.62 2 1/2 5.50 0.75
8 8.75 9.00 0.94 0.88 4 7.50 0.75
10 9.75 9.00 0.94 0.88 4 7.50 0.75
12 11.25 11.00 1.00 1.00 6 9.50 0.88
14 12.50 11.00 1.00 1.00 6 9.50 0.88
16 13.75 11.00 1.00 1.00 6 9.50 0.88
18 15.00 13.50 1.12 1.12 8 11.75 0.88
20 16.00 13.50 1.12 1.12 8 11.75 0.88
24 18.50 13.50 1.12 1.12 8 11.75 0.88

Notes:

NPS - Nominal Pipe Size,
R - Center to Base
S- Diameter of Round Base or Width of Square Base
T - Thickness of Base
U - Thickness of Ribs
W - Bolt Circle or Bolt Spacing

Related Topics:

Reference:

  • ASME B16.1-1998, Cast Iron Pipe Flanges and Flanged Fittings - Classes 25, 125, and 250