Buttweld pipe fittings are weldable pipe fittings that allow to change the direction of flow, to branch off, to reduce pipe size, or to mechanically join equipment to the system. They are a significant part of the industrial piping system.
Buttweld pipe fittings are available as elbows, concentric reducers, eccentric reducers, tees, caps, etc. Being the most common type of welded fitting, these fittings are sold in nominal pipe size and specified pipe schedule.
Seamless or welded pipes are used by buttweld fittings as the starting material, and they are designed to get the shape of elbows, reducers, tees, etc. through multiple processes.
Buttweld pipe fittings are sold the same way as the pipe is sold from Schedule 10 to Schedule 160. Because of cost advantage, welded buttweld fittings are more frequent in stainless steel.
For buttweld fittings, usual materials are A234 WPB, Stainless Steel 304 and 316, High Yield Carbon Steel, and Nickel Alloys. The dimensions and tolerances of buttweld fittings are defined according to ASME standard B6.9.
Buttweld pipe fittings like stainless steel and carbon steel provide many benefits in comparison with threaded and socket weld fittings.
Only up to 4-inch nominal sizes are available for the latter whereas for buttweld fittings, available sizes range from ½” to 72”. Some of the advantages of weld fittings are:
- The welded connection provides a more forceful connection
- The continuous metal structure increases the strength of the piping system
- Buttweld fittings along with matching pipe schedules provide seamless flow inside the pipe.
- A full penetration weld and correctly fitted LR 90 Elbow, concentric reducer, reducer, etc. provide gradual transition through welded pipe fitting.
All buttweld pipe fittings boast beveled ends consistent with ASME B16.25 standard. This helps make full penetration weld with no added preparation for the buttweld fitting.
Buttweld pipe fittings are most frequently obtainable in stainless steel, carbon steel, nickel alloy, aluminum, and high yield material. Forged fittings for sale are made in keeping with ANSI / ASME B16.9.
Types of Buttweld Pipe Fittings
Buttweld Elbow 45/90/180 Degree: The most extensively used elbow designs are the 45 degree/90 degree /180-degree elbows. The seamless pipes are heated, cut, and bent to form small buttweld elbows.
And welded pipes or steel plates are used to make larger buttweld elbows.
Two special types of elbows for buttweld pipes are:
- Reducing Elbow: It is employed to attach where inlet & outlet pipes have different bore sizes.
- Meter Elbow: It is a pipe with a right-angled bend with the possibility to calculate the flow rate with a gauge.
- Equal Tee: This buttweld fitting is employed either at 90 degrees or to connect the branch pipeline.
- Tee reduction: It is frequently used for a 90-degree branch pipeline.
- Unequal Tee: A pipe connector employed either at 90 degrees or to connect the branch pipeline.
Buttweld cross fittings are chiefly favored when pipelines are connected at 90 degrees in the branch.
Two distinct buttweld cross types are available based on their bore sizes:
- Equal Cross
- Reducing Cross
- Concentric reducer
- Eccentric Reducer
It is employed during repairs and reparation works to disrupt the flow or blind the pipeline, temporarily or permanently. Buttweld pipe caps are available in all sizes and shapes.
Read more: Applications of High Pressure Forged Fitting