A socket weld is a pipe attachment detail in which a pipe is inserted into a recessed area of a valve, fitting or flange. In contrast to butt weld fittings, socket weld fittings are mainly used for small pipe diameters (small bore piping); generally for piping whose nominal diameter is nps 2 or smaller. To join pipe to valves and fittings or to other sections of pipe, fillet-type seal welds be used. Socket-welded joints construction is a good choice wherever the benefits of high leakage integrity and great structural strength are important design considerations. 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. Some details of socket weld fittings sw fittings are family of high pressure fittings are used in various industrial processes.
- They are used for lines conveying flammable, toxic or expensive material where no leakage can be permitted, and for steam 300 to 600 psi.
- They are used only in conjunction with as me pipe and are available in the same size range.
- They are used in areas where pipe-work is permanent and are designed to provide good flow characteristics.
- They are are produced to several astm standards and are manufactured in accordance with asme B16. 11. The B b16. 11 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.
- They are available in three pressure ratings: 3000lbs, 6000lbs and 9000lbs. Types of socket weld fittings by class, size and wall thickness description class designation 3000 lbs 6000 lbs 9000 lbs elbows 45 and 90 degrees, tees, crosses, couplings, half-couplings, end or pipe caps ½ - 4 ½ - 2 ½ - 2 ½ - 4 ½ - 2 ½ - 2 ½ - 4 ½ - 2 ½ - 2 pipe size by wall thickness sch 80 & xs sch 160 xxs