# API Std 650 - Shell Nozzles (in)

Written by Jerry Ratzlaff on . Posted in American Petroleum Institute

## standards

• API Std 650 - Standard for Welded Tanks for Oil Storage

## flanged fitting

Size of

Nozzle

(NPS)

Outside

Diameter

of Pipe

(OD)

Nominal

Thickness

of Flanged

Nozzle

Pipe Wall [a]

$$t_n$$

Diameter

of Hole in

Reinforcing

Plate

$$D_R$$

Length of

Side of

Reinforcing

Plate [b] or

Diameter

$$L=D_o$$

Width of

Reinforcing

Plate

$$W$$

[c] Min. Dist.

from Shell

to Flange

Face

$$J$$

[c] Min. Dist.

from Bottom

of Tank to

Center of Nozzle

(Regular Type) [d]

$$H_N$$

[c] Min. Dist.

from Bottom

of Tank to

Center of Nozzle

(Low Type)

$$C$$

48 48 [e] 48 1/8 96 3/4 117 16 52 48 3/8
46 46 [e] 46 1/8 92 3/4 112 16 50 46 3/8
44 44 [e] 44 1/8 88 3/4 107 1/4 15 48 44 3/8
42 42 [e] 42 1/8 84 3/4 102 1/2 15 46 42 3/8
40 40 [e] 40 1/8 80 3/4 97 3/4 15 44 40 3/8
38 38 [e] 38 1/8 76 3/4 92 3/4 14 42 38 3/8
36 36 [e] 38 1/8 72 3/4 88 14 40 36 3/8
34 34 [e] 34 1/8 68 3/4 83 1/4 13 38 34 3/8
32 32 [e] 32 1/8 64 3/4 78 1/2 13 36 32 3/8
30 30 [e] 30 1/8 60 3/4 73 1/2 12 34 30 3/8
28 28 [e] 281/8 56 3/4 68 3/4 12 32 28 3/8
26 26 [e] 26 1/8 52 3/4 64 12 30 26 3/8
24 24 0.50 24 1/8 49 1/2 60 12 28 24 3/4
22 22 0.50 22 1/8 45 1/2 55 1/4 11 26 22 3/4
20 20 0.50 20 1/8 41 1/2 50 1/2 11 24 20 3/4
18 18 0.50 18 1/8 37 1/2 45 3/4 10 22 18 3/4
16 16 0.50 16 1/8 33 1/2 40 3/4 10 20 16 3/4
14 14 0.50 14 1/8 29 1/2 36 10 18 14 3/4
12 12 3/4 0.50 12 7/8 27 33 9 17 13 1/2
10 10 3/4 0.50 10 7/8 23 28 1/4 9 15 11 1/2
8 8 5/8 0.50 8 3/4 19 23 1/4 8 13 9 1/2
6 6 5/8 0.432 6 3/4 15 3/4 19 1/2 8 11 7 7/8
4 4 1/2 0.337 4 5/8 12 15 1/4 7 9 6
3 3 1/2 0.300 3 5/8 10 1/2 13 1/2 7 8 5 1/4
2 [f] 2 3/8 0.218 2 1/2 - - 6 7 [h]
1 1/2 [f] 1.90 0.200 2 - - 6 6 [h]
1 [f] 1.315 0.250 - - - 6 6 [h]
3/4 [f] 1.05 0.218 - - - 6 6 [h]

## threaded and socket welded couplings

Size of

Nozzle

(NPS)

Outside

Diameter

of Pipe

(OD)

Nominal

Thickness

of Flanged

Nozzle

Pipe Wall [a]

$$t_n$$

Diameter

of Hole in

Reinforcing

Plate

$$D_R$$

Length of

Side of

Reinforcing

Plate [b] or

Diameter

$$L=D_o$$

Width of

Reinforcing

Plate

$$W$$

[c] Min. Dist.

from Shell

to Flange

Face

$$J$$

[c] Min. Dist.

from Bottom

of Tank to

Center of Nozzle

(Regular Type) [d]

$$H_N$$

[c] Min. Dist.

from Bottom

of Tank to

Center of Nozzle

(Low Type)

$$C$$

3 [g] 4.250 Coupling 4 3/8 11 1/4 14 1/4 - 9 5 5/8
2 [f] 3.000 Coupling 3 1/8 - - - 7 [h]
1 1/2 [f] 2.500 Coupling 2 5/8 - - - 6 [h]
I [f] 1.750 Coupling 1 7/8 - - - 5 [h]
3/4 [f] 1.375 Coupling 1 1/2 - - - 4 [h]

• [a] For extra-strong pipe, see ASTM A53 or ASTM A106 for other wall thicknesses; however, piping material must conform to API Std 650 4.5.
• [b] The width of the shell plate shall be sufficient to contain the reinforcing plate and to provide clearance from the girth joint of the shell course.
• [c] Unless otherwise specified by the Purchaser, the nozzle shall be located at the minimum distance but shall also meet the weld spacing requirements of API Std 650 5.7.3.
• [d] The $$H_N$$ dimensions given in this table are for Appendix A tank designs only; see API Std 650 5.7.3 to determine minimum $$H_N$$ for basic tank designs.
• [e] See Table API Std 650 5-7b, Column 2.
• [f] Flanged nozzles and couplings in pipe sizes NPS 2 or smaller do not require reinforcing plates. $$D_R$$ will be the diameter of the hole in the shell plate, and Weld A will be as specified in Table API Std 650 5-7b, Column 6. Reinforcing plates may be used if the construction details comply with rein¬forced nozzle details.
• [g] A coupling in an NPS 3 requires reinforcement.
• [h] See API Std 650 5.7.3.