Orifice flange dimensions are covered in ASME B16.36. Orifice flanges are available from Class #300 to Class #2500. Class #300 flanges are available in threaded, slip-on, and weld neck end types. Whereas, Class# 600 and above flanges are available in only weld neck type end connection.

During an inspection of orifice flange, you should check for

  • Outer & Inner Diameter of body
  • Bolt Circle & Bolt hole Diameter
  • Thickness of weld end
  • Length of the Hub
  • Straightness and alignment of the bolt hole
  • Tap holes dimensions
orifice flange dimensions

Class 300 Orifice Flange Dimensions (Weld Neck Raised Face)

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODWelding Neck LengthRF Dia.RF HeightPCDOrifice Hole diaNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud SizeWeight in kg
ABCDEFGHI
12512536.65433.48150.8288.96.445/81253/4M164.5
1 1/24015536.67048.384732114.36.443/41357/8M206.5
25016536.68460.38492.121276.485/81253/4M167
2 1/26519036.61007387104.82149.26.483/41357/8M207.5
38021036.611788.9871272168.39.583/41357/8M209.4
410025536.6146114.390157.2220012.783/41357/8M2013.2
615032036.6206168.398215.92269.912.7123/41357/8M2014.6
820038039.7260219.1110269.92330.212.7127/81451M2430
1025044546.1321273116323.82387.312.71611651 1/8M2741
1230052049.3375323.81293812450.812.7161 1/81801 1/4M3062
1435058552.4425355.6141412.82514.412.7201 1/81851 1/4M3084
1640065055.6483406.4144469.92571.512.7201 1/41951 3/8M33111
1845071058.8533457157533.42628.612.7241 1/42051 3/8M33138
2050077562587508160584.22685.812.7241 1/42151 3/8M33171
2460091568.3702610167692.22812.812.7241 1/22401 5/8M39247

Class 600 Orifice Flange Dimensions (Weld Neck Raised Face)

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODWelding Neck LengthRF Dia.RF HeightPCDOrifice Hole diaNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud SizeWeight in kg
ABCDEFGHI
12512536.65433.58150.8788.96.445/81253/4M165.5
1 1/24015536.67048.384737114.36.443/41357/8M207.8
25016536.68460.38492.171276.485/81253/4M168.3
2 1/26519036.61007387104.87149.26.483/41357/8M2010.8
38021036.611788.9871277168.39.583/41357/8M2012.6
410027538.1152114.3102157.27215.912.787/81501M2419
615035547.7222168.3117215.97292.112.71211801 1/8M2737
820042055.6273219.1133269.97349.212.7121 1/81951 1/4M3053
1025051063.5343273152323.87431.812.7161 1/42201 3/8M3386
1230056066.7400323.8156381748912.7201 1/42301 3/8M33102
1435060569.9432355.6165412.8752712.7201 3/82401 1/2M36150
1640068576.2495406.4178469.97603.212.7201 1/22601 5/8M39190
1845074582.6546457.2184533.4765412.7201 5/82801 3/4M42240
2050081588.9610508190584.27723.912.7241 5/83001 3/4M42295
24600940101.6718609.6203692.27838.212.7241 7/83352M48365
Piping Courses

Class 900 Orifice Flange Dimensions (Weld Neck Raised Face)

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODWelding Neck LengthRF Dia.RF HeightPCDOrifice Hole diaNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud SizeWeight in kg
ABCDEFGHI
12515038.15233.58350.87101.66.447/81501M245.4
1 1/24018038.17048.389737123.86.4411601 1/8M277.8
25021538.110560.310292.17165.16.487/81501M3011.5
2 1/26524541.312473105104.87190.56.4811651 1/8M2715.8
38024038.112788.91021277190.59.587/81501M2422
410029044.5159114.3114157.2723512.781 1/81801 1/4M3022
615038055.6235168.3140215.97317.512.7121 1/81951 1/4M3070
820047063.5298219.1162269.97393.712.7121 3/82301 1/2M36119
1025054569.9368273184323.87469.912.7161 3/82401 1/2M36204
1230061079.4419323.82003817533.412.7201 3/82601 1/2M36303
1435064085.8451355.6213412.87558.812.7201 1/22801 5/8M39400
1640070588.9508406.4216469.9761612.7201 5/82901 3/4M42510
18450785101.9565457.2229533.47685.812.7201 7/83302M48738
20500855108622508248584.27749.312.72023552 1/8M52932
246001040139.7749609.6292692.27901.712.7202 1/24452 5/8M641511

Class 1500 Orifice Flange Dimensions (Weld Neck Raised Face)

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODWelding Neck LengthRF Dia.RF HeightPCDOrifice Hole diaNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud SizeWeight in kg
ABCDEFGHI
12515038.15233.58350.87101.66.447/81501M245.4
1 1/24018038.17048.389737123.86.4411601 1/8M277.8
25021538.110560.310292.17165.16.487/81501M2411.5
2 1/26524541.312473105104.87190.56.4811651 1/8M2715.8
38026547.713388.91171277203.29.581 1/81851 1/4M3022
410031054162114.3124157.27241.312.781 1/42051 3/8M3322
615039582.6229168.3171215.97317.512.7121 3/82651 1/2M3670
820048592.1292219.1213269.97393.712.7121 5/83001 3/4M42119
10250585108368273254323.87482.612.7121 7/83451M48204
12300675123.9451323.82833817571.512.71623802 1/8M52303
14350750133.4495355.6298412.8763512.7162 1/44152 3/8M56400
16400825146.1552406.4311469.97704.812.7162 1/24502 5/8M64510
18450915162597457.2327533.47774.712.7162 3/45002 7/8M72738
20500985177.8641508356584.27831.812.71635453 1/8M76932
246001170203.2762609.6406692.27990.612.7163 1/26203 5/8M901511

Class 2500 Orifice Flange Dimensions (Weld Neck Raised Face)

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODWelding Neck LengthRF Dia.RF HeightPCDOrifice Hole diaNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud SizeWeight in kg
ABCDEFGHI
12516038.15733.59250.871086.447/81501M246.5
1 1/24020544.57948.31117371466.441 1/81801 1/4M3013
25023550.89560.312792.17171.46.4811851 1/8M2719
2 1/26526557.211473143104.87196.86.481 1/82051 1/4M3024
38030566.713388.91681277228.69.581 1/42301 3/8M3343
410035576.2165114.3190157.2727312.781 1/22601 5/8M3966
6150485108235168.3273215.97368.312.7823502 1/8M52172
8200550127305219.1318269.97438.212.71223852 1/8M52261
10250675165.1375273419323.87539.812.7122 1/24902 5/8M64485
12300760184.2441323.84643817619.112.7122 3/45402 7/8M72730

Disclaimer –  Please check with ASME B16.36 Before using.

Thank You for subscribing to Hardhat Engineer. Your Ebook will Open in New Tab

HHE Subscribe Form

Use Your Genuine Email to get Updates on this Ebook in the Future.