API Std 650 - Flanged Roof Nozzles (in)

Written by Jerry Ratzlaff on . Posted in American Petroleum Institute

standards

• API Std 650 - Standard for Welded Tanks for Oil Storage
• [a] Reinforcing plates are not required on nozzles NPS 6 or smaller but may be used if desired.
Nozzle

(NPS)

Outside

Diameter

of

Pipe Neck

Diameter of

Hole in Roof

Plate or

Reinforcing

Plate

$$D_P$$

Minimum

Height of

Nozzle

$$H_R$$

Outside

Diameter of

Reinforcing

Plate [a]

$$D_R$$

1 1/2 1.90 2 6 5
2 2 3/8 2 1/2 6 7
3 3 1/2 3 5/8 6 9
4 4 1/2 4 5/8 6 11
6 6 5/8 6 3/4 6 15
8 8 5/8 8 7/8 6 18
10 10 3/4 11 8 22
12 12 3/4 13 8 24