Forged Fitting

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Socket Weld Fittings

Socket weld fittings are used for applications where a strong and long-lasting connection is required. These type of pipe fittings feature a socket where the connecting pipe has to be fitted and welded (with a fillet-type seal weld). Socket weld connections are very reliable but are time-consuming to install, due to the necessary welding operations. Socket weld fittings are available in sizes from 1/8 to 4 inches and in pressure ratings from classes 2000 to 9000.

The typical applications for socket weld fittings are:

• Steam

• Explosive fluids/gas

• Acids and toxic fluids

• Long service / durable installations

Threaded Fittings

Threaded fittings are used for non-critical pipelines such as water distribution, fire protection and cooling systems (low-pressure applications not subject to vibration, elongation and bending forces). Threaded fittings are not suited for fluids with variable temperatures, as sudden changes may crack the connection. Threaded fittings are available in gray cast iron, malleable iron, carbon steel ASTM A105, stainless steel A182 F304/F316 and in sizes from 1/8 inch to 4 inches with pressure ratings between 2000 and 6000. Although different types of threads are available, the most common type is the NPT (national pipe thread).

Elbow

Elbows are used to bend the pipework layout at 45 or 90 degrees. Forged elbows are manufactured according to ASME B16.11. A special type of elbow is the so-called “street” type.

Standard Specification for Forged Elbow
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	Seamless, ERW, Welded, Fabricated
Class	2000 LBS - 9000 LBS
Variation	45o, 90o -Threaded & Socket-Weld
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Tee

Tees are a forged steel fitting used to combine or divide process flow and Reducing Tees additionally allow for pipe size change. The run outlets of the tee are the two in-line outlets, and the branch is the third outlet.

Standard Specification for Forged Tee
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	Seamless, ERW, Welded, Fabricated
Class	2000 LBS - 9000 LBS
Variation	Equal Tee, Reducing Tee, Threaded & Socket-Weld
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Cross

Cross fittings are used to combine or split pipe or tube sections. Cross fittings have one input and three outputs (or vice versa) that intersect at 90 degree angles. All three designs come in standard designs (in which all outlets/inlets are the same diameter) and reducing designs (in which one or more is a different size).

Standard Specification for Forged Cross
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Equal Tee, Reducing Tee, Threaded & Socket-Weld
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Union

• Unions are used as an alternative to flanges connection in low-pressure small bore piping placed within a piping configuration that will allow the assembly to be disassembled for inspection, repair, or replacement.

• Unions should be positioned in locations that will facilitate the easy removal of critical pieces of equipment.

• Unions can be threaded end or socket weld ends. There are three pieces in a union, a nut, a female end, and a male end. When the female and male ends are joined, the nuts provide the necessary pressure to seal the joint.

Standard Specification for Forged Union
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Threaded & Socket-Weld
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Coupling

• It is used to connect two lengths of pipe, and Half-coupling is screwed onto the pipe, while the other end is made to be tightly inserted, or welded, onto the other end to pipe or vessel.

• Standard Couplings have female threads or open sockets at both ends, whereas reducing couplings connect smaller pipes to larger ones.

• There are three types of coupling available;

1- Full Coupling

Full Coupling is used for connecting small bore pipes. It used to connect pipe to pipe or pipe to swage or nipple. It can be threaded or socket ends types.

2- Half Coupling

Half Coupling is used for small bore branching from a vessel or large pipe. It can be threaded or socket type. It has a socket or thread end on only one side.

3- Reducing Coupling

Reducing coupling is used to connect two different sizes of pipe. It is like concentric reducer that maintains a center line of the pipe but small in size.

Standard Specification for Forged Coupling
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Full Coupling, Half Coupling, Reducing Coupling Threaded & Socket-Weld
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Cap and Head Plug

• The plug, like a cap, is designed to close off the end of a run of pipe.

• Plugs are manufactured for screwed fittings with male threads and are screwed into the end of a pipe to create a seal, whereas, Caps have female threads.

• They come with different head types, including: hex, square, and round.

Standard Specification for Forged Cap and Head Plug
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Cap: Threaded & Socket-Weld Plug: Only Threaded Hex Plug, Square Plug, Round Plug
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Nipple

• To facilitate the assembly of screwed and socket-weld fittings, small lengths of pipe called pipe nipples are used between fittings.

• Many companies will use 3” as the standard minimum for pipe nipples. This length will accommodate the amount of pipe lost inside the fitting on each end as well as provide sufficient wrench clearance during assembly for the larger screwed and socket-weld pipe sizes.

Standard Specification for Forged Nipple
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Only Threaded Barrel nipples, close nipple, hex. nipple, welding nipple
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Boss

Standard Specification for Forged Boss
Dimensions	ASME B16.11 BS 3799
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Only Threaded
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Head Bushing

Bushings are forged steel fittings that allow for a change in pipe size. Pictured here is the hex head bushing, which is most commonly used.

Standard Specification for Forged Head Bushing
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Only Threaded
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Insert

Standard Specification for Forged Insert
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	Only Threaded
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Swage Nipples

• Swages are functionally similar to reducers to make reductions in the line size on a straight run of pipe, However, they are specifically designed for screwed and socket-weld pipe.

• They have male (external) threads and can be connected to other screwed fittings without the use of a pipe nipple.

• Swages, like reducers, are available in either a concentric or eccentric shape.

• Swages are also manufactured with different preparations on the two ends.

o BBE—bevel both ends

o TBE—thread both ends

o PBE—plain both ends

o BLE/TSE—bevel large end/thread small end

o PLE/TSE—plain large end/thread small end

Standard Specification for Forged Swage Nipple
Dimensions	ASME B16.11 BS 3799 NPT threads conform to ASME B1.20.1
Size	1/4”-4”
Type	-
Class	2000 LBS - 9000 LBS
Variation	BBE, TBE, PBE, BLE/TSE, PLE/TSE
Test Certificate	MTC as per EN10204 Type 3.1 and EN10204 Type 3.2

Highlights of the Forged Fittings

Specification

• For socket welding ﬁttings, the pressure rating must be matched to the pipe wall thickness to ensure that the ﬂat of the band can accommodate the size of the ﬁllet weld required by the applicable code.

Pressure

• These fittings are available in four pressure-temperature rating class.

• 2000 class fittings are available in only in threaded type.

• 3000 ~ 6000 class fittings are available in both Threaded and Socket Weld types.

• 9000 class fittings are available in only socket weld type.

Thread

• Most screwed fittings are manufactured with internal, female threads per American Standard and API thread guidelines

• Some fittings, such as plugs and swages, however, are manufactured with external threads.

• Internal threads of threaded ﬁttings are in accordance with ASME B1.20.1-Pipe Threads, General Purpose (Inch).

Disadvantage

• Fatigue resistance is lower than that in butt-welded construction due to the use of ﬁllet welds and abrupt ﬁtting geometry, but it is still better than that of most mechanical joining methods.

Application

• The internal crevices left in socket-welded systems make them less suitable for corrosive or radioactive applications where solids buildup at the joints may cause operating or maintenance problems.

• Lines containing high pressure and temperature commodities, which are subject to movement and vibration, require fittings made of forged steel.

• Socket-welded construction is a good choice wherever the beneﬁts of high leakage integrity and great structural strength are important design considerations.

Size

• Screwed and socket-weld fittings are normally reserved for installations using fittings 4” and smaller. They are usually available in cast iron, malleable iron, or forged steel.

Cost

• Construction costs are somewhat lower than with butt-welded joints due to the lack of exacting ﬁt-up requirements and elimination of special machining for butt-weld end preparation.

Marking and Packing

• Products are packaged to ensure that there is no damage during transit. In case of exports, standard export packaging is done in wooden cases. All forged fittings are marked with Grade, Lot No, Size, Degree and our trade mark. On special requests we can also, make custom marking on our products.

Materials

ASTM A105

A350 (LF1, LF2, LF3)

ASTM A182 (Gr. 304, 304H, 309, 310, 316, 316L, 317L, 321, 347, 904L)

ASTM A182 (Gr. F 5, F 9, F 11, F 12, F 22, F 91)

ASTM A694 (Gr. F42, F46, F56, F52, F60, F65, F70)

ASTM A182 (Gr. F51, F52, F53, F54, F55, F57, F59, F60, F61),

UNS S31803, S32205, S32760, S32750

ASTM SB 336, ASTM SB 564 / 160 / 163 / 164 / 166 / 472, UNS 2200 (NICKEL 200) , UNS 2201 (NICKEL 201 ) , UNS 4400 (MONEL 400 ) , UNS 8020 ( ALLOY 20 / 20 CB 3 ) , UNS 8825 INCONEL (825) , UNS 6600 (INCONEL 600 ) , UNS 6601 (INCONEL 601) , UNS 6625 (INCONEL 625), UNS 10276 (HASTELLOY C 276)

ASTM SB 111 UNS No. C10100 , C10200 , C10300 , C10800 , C12000, C12200, C70600, C71500,

ASTM SB 466 UNS No. C70600 ( CU -NI- 90/10) , C71500 ( CU -NI- 70/30)

Standard

The dimensions of forged fittings are defined by ASME B16.11, MSS-SP 83, and MSS-SP 95 to match ASME B36.10 and ASME B36.19 pipes.

ASME B16.11

This standard covers pressure-temperature ratings, dimensions, tolerances, marking, and material requirements for forged carbon and alloy steel. Acceptable material forms are forgings, bars, seamless pipe, and seamless tubes which conform to the fittings chemical compositions, melting practices, and mechanical property requirements of ASTM A105, A182, or A350.

MSS-SP 83

This Standard Practice establishes envelope and other essential dimensions, finish, tolerances, testing, marking, material, and minimum performance requirements for forged carbon steel, alloy steel, stainless steel, and nickel alloy pipe unions, socket welding and threaded ends.

MSS-SP 95

This Standard Practice covers dimensions, finish, tolerances, marking, and material for carbon steel and alloy steel Swaged Nipples (male end reducing fittings), NPS 1/4 through NPS 12 and Bull Plugs (hollow or solid male closures) NPS 1/8 through NPS 12. These fittings are made with ends that are threaded, beveled, square cut, grooved, or any combination of these. Both concentric and eccentric Swaged Nipples are included.

ASME B1.20.1

ASME’s widely-referenced B1.20.1 Standard on Pipe Threads, General Purpose, Inch covers dimensions and gaging of the world’s most common pipe threads: NPT, NPSC, NPTR, NPSM, and NPSL.