What are pipeline system butt weld pipe fitting?
Butt welded fitting is applied to change the pipe path (elbow), reduce/increase the pipe diameter (reducer), branch (tee, cross) or close the pipe (butt welding cap). ASME B16.9 (and mss-sp 43) buttweld pipe fittings are used for pipeline system larger than 2 inches in diameter, socket weld and threaded fittings are used for smaller sizes (ASME B16.11).
Buttweld fitting includes long/short radius elbow, concentric reducer, eccentric reducer and tee pipe. Butt weld of stainless steel and carbon steel pipe fittings are necessary parts of industrial pipeline system to change direction, branch or mechanically connect equipment to the system. Buttweld pipe fittings are sold in accordance with the indicated pipe size and specified pipe schedule. Dimensions and tolerances of BW fittings are defined according to ASME standard B16.9.
The advantages of pipeline butt weld pipe fitting:
The main standards for butt welding fittings are ASME B16.9 (carbon and alloy fittings) and MSS SP 43 (integrated ASME B16.9 for stainless steel, biphase and nickel alloy BW fittings).
Butt welding fittings have the following advantages:
1.Strong and leakproof piping connections.
2.Minimize pressure intensity and turbulence in the pipeline.
3.Long service life.
4.It’s cheap to buy and deploy.
Butt weld elbow 45/90/180 degree:
ASME B16.9 butt welded elbows are manufactured in a wide range of sizes (combination of outside diameter and wall thickness) to fit any size of ASME B36.10 and ASME B36.19 carbon, alloy and stainless steel pipes (above) between 2 and 48 inches.
By cutting, heating and bending seamless steel tubes to produce bow elbows less than 24 inches in diameter. Instead, larger elbows are made of welded pipes or steel plates.
The three most common types of elbows in the pipeline are 45 degrees, 90 degrees, and 180 degrees (or elbows), as shown in the figure:
Some special types of elbows are:
Reduced elbow: use a union with two different diameters of inlet and outlet, instead of a combination of standard reduced elbow and concentric reducer.
Mitered elbow: a large elbow assembled by connecting steel plates.
Short and long radius pipeline butt weld elbow:
The distance from the center of the long radius elbow to the end is always 1.5 times the nominal pipe size, while the distance from the center of the short radius elbow is equal to the nominal pipe size.
Example. :
For 4-inch radius (LR) butt welding elbows, distance from center to surface is 4 x 25.4 x 1.5 = 152.4mm;
For short radius butt welding elbows, change the distance from center to surface to 4 x 25.4 x 1 = 101.6mm. Short radius elbows for 90 ° and 180 ° configurations only (not for 45 °); In contrast, a long radius pipe elbow applies to all angles.
