What is a Butt Weld (Buttweld) Fitting?
A buttweld fitting is a weldable pipe fitting that allows for change of direction of flow, to branch off, reduce pipe size or attach auxiliary equipment. Forged Steel buttweld fittings are manufactured in accordance with ANSI / ASME B16.9.
Butt weld fittings are available as elbows, tees, caps, reduces and out lets (olets). These fittings are the most common type of welded pipe fitting and are specified by nominal pipe size and pipe schedule. Buttweld fittings use seamless or welded pipe as the starting material and are formed (through multiple processes) to get the shape of elbows, tees and reducers etc. Just as the pipe is sold from Schedule 10 to Schedule 160, butt weld pipe fittings are sold the same way. Welded butt weld fittings are more common in stainless steel due to cost advantage. Sch 10 fittings are also more common in stainless steel butt weld fitting.
Common material for butt weld fittings are A234 WPB (A & C also available), High Yield Carbon Steel, Stainless Steel 304 and 316 and Nickel Alloys.
Buttweld pipe fittings comprise of long radius elbow, concentric reducer, eccentric reducers and Tees.They are an important part of industrial piping systems to change direction, branch off or to mechanically join equipment to the system. Buttweld fittings are sold in nominal pipe sizes with specified pipe schedule. BW fitting’s dimensions and tolerances are defined as per ASME standard B16.9.
Butt Weld fittings are also called Welded Pipe fittings. These welded fittings in carbon steel and stainless steel offer many advantages compared to threaded and socketweld fittings. The later are only available up to 4-inch nominal size whereas butt weld fittings are available in sizes from ½” to 72”. Some of the benefits of Buttweld fittings are;
Types of Butt Weld Pipe Fittings
Welded pipe fittings in carbon steel and stainless steel are the joining components that make possible the assembly of valves, pipes and equipment onto the piping system. Welded fittings compliment pipe flanges in any piping system and allows;
Change direction of flow in a piping system
Connect or joint pipes and equipment
Provide branches, access and takeoffs for auxiliary equipment
A common example using welded pipe fitting is a pipe reduced by concentric reducer, welded to a weld neck flange and connected to an equipment. Figure below represent complete collection of butt welded pipe fitting.
The carbon steel elbow mainly adopts the polygonal ring shell or the closed polyhedral sector shell with polygonal sections at both ends, which is filled with the interior of the pressure transmission medium. Under the internal pressure, the polygonal section under the internal pressure gradually becomes round and eventually becomes a ring shell. According to the needs, a ring shell can be cut into 90 degree elbows, 4 or 6 60 degree elbows or other standards. This process is suitable for making elbows. The ratio of length to diameter is greater than 1.5, which is the manufacturing method of large elbows. Set the pressure and flow of water in front of the carbon steel elbow to be the same, and the pressure loss will occur when the water flows through the pipe. If the loss is greater, the pressure out of the elbow will be smaller, 90DEG; The bend is equivalent to two 45DEG elbows. If the radius of the bend is the same, that is, the impact of the water rushing out of the elbow on the ground will be smaller.
Now, the frequency of using carbon steel elbow in various pipelines is also higher and higher, and people gradually begin to pay attention to the price. Under such circumstances, we see more opportunities. It is also this situation that enables the development of carbon steel elbow, and the momentum of development is very good. The carbon steel elbow still has great characteristics. For example, as long as the raw materials are flat plate and developable surface. The accuracy is simple and easy to install and weld.