LONG WELD NECK FLANGE

A Long Weld Neck Flange is an integral self-reinforcing Flange connection primarily for ASME Pressure Vessel applications. The Long Weld Neck (LWN) Flange  was designed to be used in place of a Weld Neck Flange and piece of pipe for a bolt up connection to the vessel. This design reduced the stress on the neck and transferred it to the base where it connected to the vessel.

The Long Weld Neck Flange is the most common of the self-reinforced nozzle designs. The heavy barrel type nozzles offer a thicker neck for higher pressure and temperature applications. The Flange end and sealing face are designed to ASME B16.5 for pipe size ½” to 24” and ASME B16.47 for pipe size 26” to 60”. Typically the longer the nominal size and pressure, the longer the length of the neck. The standard bore for the LWN Flange is the same as the pipe size but can be ordered to any bore, the standard barrel lengths are 9”, 12” and 16”, but they will be made to meet the customer’s requirements. Check out our post on how to order custom flanges.

ASME/ ANSI STANDARD

ANSI/ASME Flange Types information
ANSI/ASME Flange Types information:
ANSI/ASME Flange Face Type, Face Finish & Tolerance
ANSI/ASME Welding Neck Flanges – Welding Ends Types
ANSI/ASME B16.5 & B16.47 Ring Type Joint Flanges
ANSI/ASME B16.5 Welding Neck Flange Dimensions (150lb-2500lb)
ANSI/ASME B16.5 Slip On Flange Dimensions (150lb-1500lb)
ANSI/ASME Blind Flange Dimensions (150lb-2500lb)
ANSI/ASME B16.5 Socket Welding Flange Dimensions (150lb-1500lb)
ANSI/ASME B16.5 Lap Joint Flange Dimensions (150lb-2500lb)
ANSI/ASME B16.5 Threaded Flange Dimensions (150lb-2500lb)
ANSI/ASME B16.47 Flange Series A / MSS SP44 Flange (150lb-900lb)
ANSI/ASME B16.47 Flange Series B / API 605 Flange Dimensions (75lb-900lb)
ANSI/ASME B16.48
Long weld neck flange
ASME VIII Flange Series over 60in flange

All the flange list

ANSI/ASME FLANGE STANDARDEN FLANGE STANDARDBS FLANGE STANDARD
DIN FLANGE STANDARDJIS FLANGE STANDARDUNI FLANGE STANDARD
API 6A/6B/6BX FLANGE STANDARDAWWA FLANGE STANDARDKS FLANGE STANDARD
GOST/ГОСТ FLANGE STANDARDISO FLANGE STANDARDAS FLANGE STANDARD
SANS/SABS FLANGE STANDARDLONG WELD NECK FLANGEASME VIII FLANGE

 

All dimensions are in "mm" and All weights are in "kg" unless noted otherwise specified.

you may also check non standard sizes flange weight online calculation,flange surface area online calculation,flange surface volume online calculation from our pipeline tool link:

https://alloypipefitting.com/flange-calculator.html

The whole weight and dimension list of  flange directory

Flange-dimension-and-weight

ansi-asme-b16-5-long-weld-neck-flanges

ansi-asme-b16-5-long-weld-neck-flanges

ANSI ASME B16.5 CLASS 150 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hubof Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1/2"

89

11.1

34.9

30.2

12.7

228. 6

304. 8

60.5

4

15.8

3/4"

98.5

12.7

42.9

38.1

19.1

228. 6

304. 8

69.9

4

15.8

1"

108.

0

14.3

50.8

50.8

25.4

228. 6

304. 8

79.4

4

15.8

1-1/4"

117.

5

15.9

63.5

60.3

31.8

228. 6

304. 8

88.9

4

15.8

1-1/2"

127.

0

17.5

73

66.7

38.1

228. 6

304. 8

98.4

4

15.8

2"

152.

5

19.1

92.1

82.5

50.8

228. 6

304. 8

120.

7

4

19

2-1/2"

178.

0

22.2

104.

8

95.2

63.5

228. 6

304. 8

139.

7

4

19

3"

190.

5

23.8

127.

0

107. 9

76.2

228. 6

304. 8

152.

4

4

19

3-1/2"

216.

0

23.8

139.

9

124. 0

88.9

228. 6

304. 8

177.

8

8

19

4"

228.

5

23.8

157.

2

139. 7

101. 6

228. 6

304. 8

190.

5

8

19

5"

254.

0

23.8

185.

7

165. 1

127. 0

228. 6

304. 8

215.

9

8

22.5

6"

279.

5

25.4

215.

9

196. 8

152. 4

228. 6

304. 8

241.

3

8

22.5

8"

343.

0

28.6

269.

9

247. 6

203. 2

228. 6

304. 8

298.

4

8

22.5

10"

406.

5

30.2

323.

9

304. 8

254. 0

228. 6

304. 8

361.

9

12

25.5

12"

482.

5

31.8

381.

0

365. 1

304. 8

228. 6

304. 8

431.

8

12

25.5

14"

533.

5

34.9

412.

8

406. 4

355. 6

228. 6

304. 8

476.

2

12

28.5

16"

597.

0

36.5

469.

9

457. 2

406. 4

228. 6

304. 8

539.

7

16

28.5

18"

635.

0

39.7

533.

4

508. 0

457. 2

228. 6

304. 8

577.

8

16

31.8

20"

698.

5

42.9

584.

2

558. 8

508. 0

228. 6

304. 8

635.

0

20

31.8

24"

813.

0

47

692.

2

666. 7

609. 6

228. 6

304. 8

749.

3

20

35.1

ANSI ASME B16.5 CLASS 300 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hubof Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1/2"

95.5

14.3

34.9

38.1

12.7

228. 6

304. 8

66.7

4

15.8

3/4"

117. 5

15.9

42.9

47.6

19.1

228. 6

304. 8

82.5

4

19

1"

124. 0

17.5

50.8

54

25.4

228. 6

304. 8

88.9

4

19

1-1/4"

133. 5

19.1

63.5

63.5

31.8

228. 6

304. 8

98.4

4

19

1-1/2"

155. 5

20.6

73

69.8

38.1

228. 6

304. 8

114.

3

4

22.5

2"

165. 0

22.2

92.1

82.5

50.8

228. 6

304. 8

127.

0

8

19

2-1/2"

190. 5

25.4

104.

8

100.

0

63.5

228. 6

304. 8

149.

2

8

22.5

3"

209. 5

28.6

127.

0

117.

5

76.2

228. 6

304. 8

168.

3

8

22.5

3-1/2"

228. 5

30.2

139.

7

133.

4

88.9

228. 6

304. 8

184.

1

8

22.5

4"

254. 0

31.8

157.

2

146.

0

101. 6

228. 6

304. 8

200.

0

8

22.5

5"

279. 5

34.9

185.

7

177.

8

127. 0

228. 6

304. 8

234.

9

8

22.5

6"

317. 5

36.5

215.

9

206.

4

152. 4

228. 6

304. 8

269.

9

12

22.5

8"

381. 0

41.3

269.

9

260.

3

203. 2

228. 6

304. 8

330.

2

12

25.5

10"

444. 5

47.6

323.

9

320.

7

254. 0

228. 6

304. 8

387.

3

16

28.5

12"

520. 5

50.8

381.

0

374.

6

304. 8

228. 6

304. 8

450.

8

16

31.8

14"

584. 0

54

412.

8

425.

4

355. 6

228. 6

304. 8

514.

3

20

31.8

16"

647. 5

57.2

469.

9

482.

6

406. 4

228. 6

304. 8

571.

5

20

35.1

18"

711. 0

60.3

533.

4

533.

4

457. 2

228. 6

304. 8

628.

6

24

35.1

20"

774. 5

63.5

584.

2

587.

3

508. 0

228. 6

304. 8

685.

8

24

35.1

24"

914. 5

69.9

692.

2

701.

6

609. 6

228. 6

304. 8

812.

8

24

41.2

ANSI ASME B16.5 CLASS 400 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hubof Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1"

124. 0

17.5

50.8

54

25.4

228. 6

304. 8

88.9

4

19

1-1/4"

133. 5

20.6

63.5

63.5

31.8

228. 6

304. 8

98.4

4

19

1-1/2"

155. 5

22.2

73

69.8

38.1

228. 6

304. 8

114.

3

4

22.5

2"

165. 0

25.4

92.1

82.5

50.8

228. 6

304. 8

127.

0

8

19

2-1/2"

190. 5

28.6

104.

8

100.

0

63.5

228. 6

304. 8

149.

2

8

22.5

3"

209. 5

31.8

127.

0

117.

5

76.2

228. 6

304. 8

168.

1

8

22.5

3-1/2"

228. 5

34.9

139.

7

133.

4

88.9

228. 6

304. 8

184.

2

8

25.5

4"

254. 0

34.9

157.

2

146.

0

101. 6

228. 6

304. 8

200.

0

8

25.5

5"

279. 5

38.1

185.

7

177.

8

127. 0

228. 6

304. 8

234.

9

8

25.5

6"

317. 5

41.3

215.

9

206.

4

152. 4

228. 6

304. 8

269.

9

12

25.5

8"

381. 0

47.6

269.

9

260.

3

203. 2

228. 6

304. 8

330.

2

12

28.5

10"

444. 5

54

323.

9

320.

7

254. 0

228. 6

304. 8

387.

3

16

31.8

12"

520. 5

57.2

381.

0

374.

6

304. 8

228. 6

304. 8

450.

8

16

35.1

14"

584. 0

60.3

412.

8

425.

4

355. 6

228. 6

304. 8

514.

3

20

35.1

16"

647. 5

63.5

469.

9

482.

6

406. 4

228. 6

304. 8

571.

5

20

38.1

18"

711. 0

66.7

533.

4

533.

4

457. 2

228. 6

304. 8

628.

6

24

38.1

20"

774. 5

69.9

584.

2

587.

3

508. 0

228. 6

304. 8

685.

8

24

41.2

24"

914. 5

76.2

692.

2

701.

6

609. 6

228. 6

304. 8

812.

8

24

47.8

ANSI ASME B16.5 CLASS 600 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hubof Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1"

124. 0

17.5

50.8

54

25.4

228. 6

304. 8

88.9

4

19

1-1/4"

133. 5

20.6

63.5

63.5

31.8

228. 6

304. 8

98.4

4

19

1-1/2"

155. 5

22.2

73

69.8

38.1

228. 6

304. 8

114.

3

4

22.5

2"

165. 0

25.4

92.1

82.5

50.8

228. 6

304. 8

127.

0

8

19

2-1/2"

190. 5

28.6

104.

8

100.

0

63.5

228. 6

304. 8

149.

2

8

22.5

3"

209. 5

31.8

127.

0

117.

5

76.2

228. 6

304. 8

168.

1

8

22.5

3-1/2"

228. 5

34.9

139.

7

133.

4

88.9

228. 6

304. 8

184.

2

8

25.5

4"

273. 0

38.1

157.

2

152.

4

101. 6

228. 6

304. 8

215.

9

8

25.5

5"

330. 0

44.5

185.

7

190.

5

127. 0

228. 6

304. 8

266.

7

8

28.5

6"

355. 5

47.6

215.

9

222.

2

152. 4

228. 6

304. 8

292.

1

12

28.5

8"

419. 0

55.6

269.

9

273.

0

203. 2

228. 6

304. 8

349.

3

12

31.8

10"

508. 0

63.5

323.

9

342.

9

254. 0

228. 6

304. 8

431.

8

16

35.1

12"

559. 0

66.7

381.

0

400.

0

304. 8

228. 6

304. 8

489.

0

20

35.1

14"

603. 5

69.9

412.

8

431.

8

355. 6

228. 6

304. 8

527.

1

20

38.1

16"

686. 0

76.2

469.

9

495.

3

406. 4

228. 6

304. 8

603.

3

20

41.2

18"

743. 0

82.6

533.

4

546.

1

457. 2

228. 6

304. 8

654.

1

20

44.5

20"

813. 0

88.9

584.

2

609.

6

508. 0

228. 6

304. 8

723.

9

24

44.5

24"

940. 0

101. 6

692.

2

717.

5

609. 6

228. 6

304. 8

838.

2

24

50.8

ANSI ASME B16.5 CLASS 900 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hubof Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1"

149. 5

28.6

50.8

52.4

25.4

228. 6

304. 8

101.

6

4

25.5

1-1/4"

159. 0

28.6

63.5

63.5

31.8

228. 6

304. 8

111.

1

4

25.5

1-1/2"

178. 0

31.8

73

69.9

38.1

228. 6

304. 8

123.

8

4

28.5

2"

216. 0

38.1

92.1

104. 8

50.8

228. 6

304. 8

165.

1

8

25.5

2-1/2"

244. 5

41.3

104.

8

123. 8

63.5

228. 6

304. 8

190.

5

8

28.5

3"

241. 5

38.1

127.

0

127. 0

76.2

228. 6

304. 8

190.

5

8

25.5

4"

292. 0

44.5

157.

2

158. 7

101. 6

228. 6

304. 8

235.

0

8

31.8

5"

349. 5

50.8

185.

7

190. 5

127. 0

228. 6

304. 8

279.

4

8

35.1

6"

381. 0

55.6

215.

9

235. 0

152. 4

228. 6

304. 8

317.

5

12

31.8

8"

470. 0

63.5

269.

9

298. 5

203. 2

228. 6

304. 8

393.

7

12

38.1

10"

546. 0

69.9

323.

9

368. 3

254. 0

228. 6

304. 8

469.

9

16

38.1

12"

609. 5

79.4

381.

0

419. 1

304. 8

228. 6

304. 8

533.

4

20

38.1

14"

641. 5

85.7

412.

8

450. 9

355. 6

228. 6

304. 8

558.

8

20

41

16"

705. 0

88.9

469.

9

508. 0

406. 4

228. 6

304. 8

616.

0

20

44.5

18"

787. 5

101. 6

533.

4

565. 2

457. 2

228. 6

304. 8

685.

8

20

50.8

20"

857. 5

108. 0

584.

2

622. 3

508. 0

228. 6

304. 8

749.

3

20

54

24"

1014.5

139. 7

692.

2

749. 3

609. 6

228. 6

304. 8

901.

7

20

66.5

ANSI ASME B16.5 CLASS 1500 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hub

of Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1"

149. 5

28.6

50.8

52.4

25.4

228. 6

304. 8

101.

6

4

25.5

1-1/4"

159. 0

28.6

63.5

63.5

31.8

228. 6

304. 8

111.

1

4

25.5

1-1/2"

178. 0

31.8

73

69.9

38.1

228. 6

304. 8

123.

8

4

28.5

2"

216. 0

38.1

92.1

104. 8

50.8

228. 6

304. 8

165.

1

8

25.5

2-1/2"

244. 5

41.3

104.

8

123. 8

63.5

228. 6

304. 8

190.

5

8

28.5

3"

267. 0

47.6

127.

0

133. 4

76.2

228. 6

304. 8

203.

2

8

31.8

4"

311. 0

54

157.

2

161. 9

101. 6

228. 6

304. 8

241.

3

8

35.1

5"

374. 5

73

185.

7

196. 9

127. 0

228. 6

304. 8

292.

1

8

41

6"

393. 5

82.6

215.

9

228. 6

152. 4

228. 6

304. 8

317.

5

12

38.1

8"

483. 0

92.1

269.

9

292. 1

203. 2

228. 6

304. 8

393.

7

12

44.5

10"

584. 0

108.

0

323.

9

368. 3

254. 0

406. 4

406. 4

482.

6

12

50.8

12"

673. 0

123.

8

381.

0

450. 9

304. 8

406. 4

406. 4

571.

5

16

54

14"

749. 5

133.

4

412.

8

495. 3

355. 6

635.

0

16

60.5

16"

825. 5

146.

1

469.

9

552. 5

406. 4

704.

9

16

66.5

18"

914. 5

161.

9

533.

4

596. 9

457. 2

774.

7

16

73

20"

984. 0

177.

8

584.

2

641. 4

508. 0

831.

9

16

79.5

24"

1168.5

203.

2

692.

2

762. 0

609. 6

990.

6

16

92

ANSI ASME B16.5 CLASS 2500 LONG WELD NECK FLANGES DIMENSIONS

Pipe

O.D.

Thk. Of

Diameter

Hub

Diameter

Length

Diam. of

Number

Diam. of

Normal

Flange

of Raised

Diameter

Bolt

Flange

of Bore

Through Hub

of Bolts

Holes

Diam.

Min

Face

at Bevel

Circle

inch

O

C

R

A

BH

H1

BC

nd

1"

159. 0

34.9

50.8

57.2

25.4

25.4

304. 8

108.

0

4

25.5

1-1/4"

184. 0

38.1

63.5

73

31.8

31.8

304. 8

130.

2

4

28.5

1-1/2"

203. 0

44.5

73

79.4

38.1

38.1

304. 8

146.

1

4

31.8

2"

235. 0

50.8

92.1

95.3

50.8

50.8

304. 8

171.

5

8

28.5

2-1/2"

267. 0

57.2

104.

8

114.

3

63.5

63.5

304. 8

196.

9

8

31.8

3"

305. 0

66.7

127.

0

133.

4

76.2

76.2

304. 8

228.

6

8

35

4"

355. 5

76.2

157.

2

165.

1

101. 6

101. 6

304. 8

273.

1

8

41

5"

419. 0

92.1

185.

7

203.

2

127. 0

127. 0

304. 8

323.

9

8

48

6"

483. 0

108. 0

215.

9

235.

0

152. 4

152. 4

304. 8

368.

3

8

54

8"

552. 5

127. 0

269.

9

304.

8

203. 2

203. 2

304. 8

438.

2

12

54

10"

673. 0

165. 1

323.

9

374.

7

254. 0

254. 0

406. 4

539.

8

12

66.5

12"

762. 0

184. 2

381.

0

441.

3

304. 8

304. 8

406. 4

619.

1

12

73