Long Weld neck flange dimensions are covered in ASME B16.5 – which covers Pipe Flanges and Flanged Fittings for size NPS ½” to 24” for above NPS 26” to 60” it should be as per ASME B16.47.

During the dimensional inspection of a 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
long weld neck flange dimensions

Class 150 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCMachine Bolt LengthRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/215909.63021.334.9260.3As Required41/250555/8M14
3/42010011.23826.742.9269.9As Required41/250655/8M14
12511012.74933.450.8279.4As Required41/255655/8M14
1 1/43211514.35942.263.5288.9As Required41/255705/8M14
1 1/24012515.96548.373298.4As Required41/265705/8M14
25015017.57860.392.12120.7As Required45/870853/4M16
2 1/26518020.79073104.82139.7As Required45/875903/4M16
38019022.310888.91272152.4As Required45/875903/4M16
3 1/29021522.3122101.6139.72177.8As Required85/875903/4M16
410023022.3135114.3157.22190.5As Required85/875903/4M16
512525522.3164141.3185.72215.9As Required83/485957/8M20
615028023.9192168.3215.92241.3As Required83/4851007/8M20
820034527246219.1269.92298.5As Required83/4901107/8M20
1025040528.6305273323.82362As Required127/81001151M24
1230048530.2365323.83812431.8As Required127/81001201M24
1435053533.4400355.6412.82476.3As Required1211151351 1/8M27
1640059535457406.4469.92539.8As Required1611151351 1/8M27
1845063538.1505457.2533.42577.9As Required161 1/81251451 1/4M30
2050070041.3559508584.22635As Required201 1/81401601 1/4M30
2460081546.1663610692.22749.3As Required201 1/41501701 3/8M33

Class 300 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCMachine Bolt LengthRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/2159512.73821.334.9266.7As Required41/255655/8M14
3/42011514.34826.742.9282.6As Required45/865753/4M16
12512515.95433.450.8288.9As Required45/865753/4M16
1 1/43213517.56442.263.5298.4As Required45/870853/4M16
1 1/24015519.17048.3732114.3As Required43/475907/8M20
25016520.78460.392.12127As Required85/875903/4M16
2 1/26519023.910073104.82149.2As Required83/4851007/8M20
3802102711788.91272168.3As Required83/4901107/8M20
3 1/29023028.6133101.6139.72184.2As Required83/4951107/8M20
410025530.2146114.3157.22200As Required83/4951157/8M20
512528033.4178141.3185.72235As Required83/41101207/8M20
615032035206168.3215.92269.9As Required123/41101207/8M20
820038039.7260219.1269.92330.2As Required127/81201401M24
1025044546.1321273323.82387.4As Required1611401601 1/8M27
1230052049.3375323.83812450.8As Required161 1/81451701 1/4M30
1435058552.4425355.6412.82514.4As Required201 1/81601801 1/4M30
1640065055.6483406.4469.92571.5As Required201 1/41651901 3/8M33
1845071058.8533457533.42628.6As Required241 1/41701951 3/8M33
2050077562587508584.22685.8As Required241 1/41852051 3/8M33
2460091568.3702610692.22812.8As Required241 1/22052301 5/8M39
Piping Courses

Class 400 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/2159514.33821.334.9766.7As Required41/2755/8M14
3/42011515.94826.742.9782.6As Required45/8903/4M16
12512517.55433.450.8788.9As Required45/8903/4M16
1 1/43213520.76442.263.5798.4As Required45/8953/4M16
1 1/24015522.37048.3737114.3As Required43/41107/8M20
25016525.48460.392.17127As Required85/81103/4M16
2 1/26519028.610073104.87149.2As Required83/41207/8M20
38021031.811788.91277168.3As Required83/41257/8M20
3 1/29023035133101.6N/A7184.2As Required87/81401M24
410025535146114.3157.27200As Required87/81401M24
512528038.1178141.3185.77235As Required87/81451M24
615032041.3206168.3215.97269.9As Required127/81501M24
820038047.7260219.1269.97330As Required1211701 1/8M27
1025044554321273323.87387.4As Required161 1/81901 1/4M30
1230052057.2375323.83817450.8As Required161 1/42051 3/8M33
1435058560.4425355.6412.87514.4As Required201 1/42101 3/8M33
1640065063.5483406.4469.97571.5As Required201 3/82201 1/2M36
1845071066.7533457533.47628.6As Required241 3/82301 1/2M36
2050077569.9587508584.27685.8As Required241 1/22401 3/4M39
2460091576.2702610692.27812.8As Required241 3/42651 7/8M45

Class 600 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/2159514.33821.334.9766.7As Required41/2755/8M14
3/42011515.94826.742.9782.6As Required45/8903/4M16
12512517.55433.450.8788.9As Required45/8903/4M16
1 1/43213520.76442.263.5798.4As Required45/8953/4M16
1 1/24015522.37048.3737114.3As Required43/41107/8M20
25016525.48460.392.17127As Required85/81103/4M16
2 1/26519028.610073104.87149.2As Required83/41207/8M20
38021031.811788.91277168.3As Required83/41257/8M20
3 1/29023035133101.6N/A7184.2As Required87/81401M24
410027538.1152114.3157.27215.9As Required87/81451M24
512533044.5189141.3185.77266.7As Required811651 1/8M27
615035547.7222168.3215.97292.1As Required1211701 1/8M27
820042055.6273219.1269.97349.2As Required121 1/81901 1/4M30
1025051063.5343273323.87431.8As Required161 1/42151 3/8M33
1230056066.7400323.83817489As Required201 1/42201 3/8M33
1435060569.9432355.6412.87527As Required201 3/82351 1/2M36
1640068576.2495406.4469.97603.2As Required201 1/22551 5/8M39
1845074582.6546457533.47654As Required201 5/82751 3/4M42
2050081588.9610508584.27723.9As Required241 5/82851 3/4M42

Class 900 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/21512022.33821.334.9782.6As Required43/41107/8M20
3/42013025.44426.742.9788.9As Required43/41157/8M20
12515028.65233.450.87101.6As Required47/81251M24
1 1/43216028.66442.263.57111.1As Required47/81251M24
1 1/24018031.87048.3737123.8As Required411401 1/8M27
25021538.110560.392.17165.1As Required87/81451M24
2 1/26524541.312473104.87190.5As Required811601 1/8M27
38024038.112788.91277190.5As Required87/81451M24
410029044.5159114.3157.27235As Required81 1/81701 1/4M30
512535050.8190141.3185.77279.4As Required81 1/41901 3/8M33
615038055.6235168.3215.97317.5As Required121 1/81901 1/4M30
820047063.5298219.1269.97393.7As Required121 3/82201 1/2M36
1025054569.9368273323.87469.9As Required161 3/82351 1/2M36
1230061079.4419323.83817533.4As Required201 3/82551 1/2M36
1435064085.8451355.6412.87558.8As Required201 1/22751 5/8M39
1640070588.9508406.4469.97616As Required201 5/82851 3/4M42
18450785101.6565457533.47685.8As Required201 7/83252M48
20500855108622508584.27749.3As Required2023502 1/8M52
246001040139.7749610692.27901.7As Required202 1/24402 5/8M64

Class 1500 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/21512022.33821.334.9782.6As Required43/41107/8M20
3/42013025.44426.742.9788.9As Required43/41157/8M20
12515028.65233.450.87101.6As Required47/81251M24
1 1/43216028.66442.263.57111.1As Required47/81251M24
1 1/24018031.87048.3737123.8As Required411401 1/8M27
25021538.110560.392.17165.1As Required87/81451M24
2 1/26524541.312473104.87190.5As Required811601 1/8M27
38026547.713388.91277203.2As Required81 1/81801 1/4M30
410031054162114.3157.27241.3As Required81 1/41951 3/8M33
512537573.1197141.3185.77292.1As Required81 1/22501 5/8M39
615039582.6229168.3215.97317.5As Required121 3/82601 1/2M36
820048592.1292219.1269.97393.7As Required121 5/82901 3/4M42
10250585108368273323.87482.6As Required121 7/83352M48
12300675123.9451323.83817571.5As Required1623752 1/8M52
14350750133.4495355.6412.87635As Required162 1/44052 3/8M56
16400825146.1552406.4469.97704.8As Required162 1/24452 5/8M64
18450915162597457533.47774.7As Required162 3/44952 7/8M72
20500985177.8641508584.27831.8As Required1635403 1/8M76
246001170203.2762610692.27990.6As Required163 1/26153 5/8M90

Class 2500 Long Weld Neck Flange Dimensions

Size in InchSize in mmOuter Dia.Flange Thick.Hub ODWeld Neck ODRF Dia.RF HeightPCDHub LengthNo of BoltsBolt Size UNCRF Stud LengthHole SizeISO Stud Size
ABCDEFGH
1/21513530.24321.334.9788.9As Required43/41207/8M20
3/42014031.85126.742.9795.2As Required43/41257/8M20
125160355733.450.87108As Required47/81401M24
1 1/43218538.17342.263.57130.2As Required411501 1/8M27
1 1/24020544.57948.3737146As Required41 1/81701 1/4M30
25023550.99560.392.17171.4As Required811801 1/8M27
2 1/26526557.211473104.87196.8As Required81 1/81951 1/4M30
38030566.713388.91277228.6As Required81 1/42201 3/8M33
410035576.2165114.3157.27273As Required81 1/22551 5/8M39
512542092.1203141.3185.77323.8As Required81 3/43001 7/8M45
6150485108235168.3215.97368.3As Required823452 1/8M52
8200550127305219.1269.97438.2As Required1223802 1/8M52
10250675165.1375273323.87539.8As Required122 1/24902 5/8M64
12300760184.2441323.83817619.1As Required122 3/45402 7/8M72

Disclaimer –  Please check with ASME B16.5 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.