Fitting

Factory-Made Wrought Buttwelding Fittings

ASME B16.9 standardizes factory-made wrought buttwelding fittings such as elbows, tees, reducers, caps, and returns. It establishes the overall dimensions, tolerances, testing requirements, and marking systems for these components to ensure proper fit-up and structural integrity with connecting pipes in high-pressure process piping systems.

Forged Fittings, Socket-Welding and Threaded

ASME B16.11 covers ratings, dimensions, tolerances, marking, and material requirements for forged fittings, specifically socket-welding and threaded types. These are massive, thick-walled fittings engineered to resist extreme pressures, mechanical vibration, and external impacts in small-bore piping systems (NPS 2 and smaller).

Wrought Steel Buttwelding Short Radius Elbows and Returns

ASME B16.28 specifies dimensions and tolerances for short radius (SR) wrought steel buttwelding elbows and returns. These fittings are specialized components used primarily in applications where spatial constraints absolutely prohibit the use of standard long radius fittings.

Buttwelding Ends

ASME B16.25 dictates the preparation of buttwelding ends of piping components to be joined into a piping system by welding. It specifies the precise bevel angles, root faces, and inside/outside contours required to guarantee a metallurgically sound weld joint that allows for full penetration.

Ferrous Pipe Plugs, Bushings, and Locknuts with Pipe Threads

ASME B16.14 provides dimensional, material, and threading requirements for minor ferrous threaded accessories: pipe plugs, bushings, and locknuts used primarily in low to medium pressure piping systems and utility networks.

Malleable Iron Threaded Fittings

ASME B16.3 covers dimensions, pressure-temperature ratings, and testing for threaded fittings made of malleable iron. These are standard low-to-moderate pressure fittings utilized universally in commercial construction, HVAC, and light industrial applications.

Gray Iron Threaded Fittings

ASME B16.4 covers dimensions, ratings, and tolerances for gray iron threaded fittings. These are low-pressure fittings relegated to applications where the improved ductility of malleable iron (B16.3) is not required and extreme cost-savings are the primary goal.

Cast Copper Alloy Threaded Fittings

ASME B16.15 covers dimensions and pressure-temperature ratings for cast copper alloy (brass and bronze) threaded fittings. These are utilized extensively in domestic water, marine environments, and specialized clean gas applications.

Pipe Threads, General Purpose (NPT)

Specifies dimensions, tolerances, and gauging methods for general-purpose inch taper pipe threads (NPT) in sizes 1/16″ through 12″ NPS, along with straight pipe thread variants (NPSC, NPSM, NPSL, NPTR). NPT threads achieve mechanical engagement through a 60° taper form at a rate of ¾ in/ft on diameter, but always require a compatible thread sealant to achieve a leak-tight joint — the thread form alone does not seal.

Dryseal Pipe Threads (NPTF)

Specifies dimensions, tolerances, and gauging for dryseal (NPTF) inch pipe threads in sizes 1/16″ through 2″ NPS, where a pressure-tight joint is achieved by metal-to-metal contact of the thread crests and roots — no thread sealant is required. The tighter crest/root tolerances compared to NPT force interference that closes the helical leak path inherent in the standard NPT form.

Factory-Made Wrought Steel Buttwelding Induction Bends for Transportation and Distribution Systems

Manufacturing, dimensions, materials, qualification, and testing of factory-made induction bends for pipeline systems.