ASME B16.11 Forged Fittings, Socket-Welding and Threaded

ASME B16.11 is a standard established by the American Society of Mechanical Engineers (ASME) that covers ratings, dimensions, tolerances, marking, and material requirements for forged fittings, both socket-welding and threaded. The following are the types of fittings by class designation and NPS size range covered by ASME B16.11:

NOTE: (1) Plugs and bushings are not identified by class designation. They may be used for ratings up to Class 6000 designation.

 

This standard applies to pipe fittings in classes 2000, 3000, and 6000 for threaded end fittings and classes 3000, 6000, and 9000 for socket weld end fittings.

 

ASME B16.11 standard forged fittings include socket-welded elbows, tees, crosses, socket-welded couplings, bosses, caps, couplets, threaded elbows, threaded street elbows, threaded couplings, plugs and bushings. It is as illustrated in Tables 1 through 6 inclusive.

GENERAL NOTE: Dimensions are in millimeters.

NOTE: (1) Average of socket wall thickness around periphery shall not be less than listed values. The minimum values are permitted in localized areas.

GENERAL NOTE: Dimensions are in millimeters.

NOTE: (1) Average of socket wall thickness around periphery shall not be less than listed values. The minimum values are permitted in localized areas.

GENERAL NOTE: Dimensions are in millimeters.

NOTE: (1) Dimension B is the minimum length of perfect thread. The length of useful thread (B plus threads with fully formed roots and flat crests) shall not be less than L2 (effective length of external thread) required by the American National Standard for Pipe Threads.

GENERAL NOTE: Dimensions are in millimeters.

NOTES:

(1) Dimension A of Table 2 for the appropriate fitting size may also be used at the option of the manufacturer.

(2) Dimension H of Table 2 for the appropriate fitting size may also be used at the option of the manufacturer.

(3) Wall thickness before threading.

(4) Dimension B is the minimum length of perfect thread. The length of useful thread (B plus threads with fully formed roots and flat crests) shall not be less than L2 (effective length of external thread) required by the American National Standard for Pipe Threads (ASME B1.20.1).

GENERAL NOTES:

(a) Dimensions are in millimeters.

(b) The wall thickness away from the threaded ends shall meet the minimum wall thickness requirements of Table I-2 for the appropriate NPS and Class Designation fitting.

NOTE: (1) Dimension B is the minimum length of perfect thread. The length of useful thread (B plus threads with fully formed roots and flat crests) shall not be less than L2 (effective length of external thread) required by the American National Standard for Pipe Threads (ASME B1.20.1).

GENERAL NOTE: Dimensions are in millimeters.

NOTES:

(1) Cautionary Note Regarding Hex Bushings: Hex head bushings of one-size reduction should not be used in services where they might be subject to harmful loads and forces other than internal pressures.

(2) Manufacturer's applied tolerance shall ensure dimension will fit U.S. Customary tooling.

Correlation of Fittings Class With Schedule Number or Wall Designation of Pipe Table

 

Class Designation of Fittings	Type of Fitting	Pipe Used for Rating Basis
		Schedule No.	Wall Designation
2000 3000 6000 3000 6000 9000	Threaded Threaded Threaded Socket-welding Socket-welding Socket-welding	80 160 ... 80 160 ...	XS ... XXS XS ... XXS

 

NOTE: (1) This table is not intended to restrict the use of pipe of thinner or thicker wall with fittings. The pipe actually used may be thinner or thicker in nominal wall than that shown in the table. When thinner pipe is used, its strength may govern the rating. When thicker pipe is used (e.g., for mechanical strength), the strength of the fitting governs the rating.

 

Nominal Wall Thickness of Schedule 160 and Double Extra Strong Pipe

 

NPS	Schedule 160		XXS
	mm	In.	mm	In.
1/8 1/4 3/8	3.15 3.68 4.01	0.124 0.145 0.158	4.83 6.05 6.40	0.190 0.238 0.252