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
Benefits of butt weld pipe fittings
The benefit to using a butt weld fitting is that it doesn’t leak. Because the butt weld is welded directly to pipe and not simply bolted together, it is not only much stronger than a typical fitting, but it allows for better flow through the system with less resistance to friction. Welded fittings also allows for better layout designs through key features such as being more compact and greater in strength.
Manufacturing standards are governed under ANSI/ASME B 16.9. Butt-Weld Fittings are available in variety of kinds such as tees, caps, elbows, reducers and outlets.
Pipe elbows
Pipe elbows are used to be installed between two lengths of pipe or tube allowing a change of direction,usually these elbows distinguished by connection ends.
Pipe bend
The advantage of the pipe bend is that it can adapt to the requirements of long-distance transition and is used to change the direction of the pipeline.
Pipe tee
A pipe tee is also called triplet,three way and “T” pieces and it can be used to either combine or split a fluid flow.
Pipe reducers
Pipe Reducers are the component in a pipeline that reduces the pipe size from a larger to a smaller bore (inner diameter).
End caps
End caps are usually used for protecting the end of pipe and other fittings…
Stub end
Stub ends are buttweld fittings that can be used alternatively to welding neck flanges to make flanged connections.
Pipe cross
A pipe cross is a kind of pipe fitting that be used in the place where four pipes meet together.
Saddle previously
Saddle previously is the ventilation ducts ‘crotch tee’, its shaped like pants, there Equal and unequal diameter, the formal name is “tube tapered pants tee.”
- Welded connection offers a more robust connection
- Continuous metal structure adds to the strength of the piping system
- Buttweld fittings with matching pipe schedules, offers seamless flow inside the pipe. A full penetration weld and properly fitted LR 90 Elbow, Reducer, Concentric reducer etc. offers gradual transition via welded pipe fitting.
- Option of various turn radius using Short Radius (SR), Long Radius (LR) or 3R Elbows
- Cost effective compared to their expensive threaded or socket weld counter parts.
- Stainless Steel Welded Fittings are also available in SCH 10, allowing a more thinner wall option.
- Stainless Steel Butt Weld Fittings are more common in SCH 10 and SCH 40 configuration.
All butt weld fittings have beveled ends as per ASME B16.25 standard. This helps create full penetration weld without any extra preparation needed for the butt weld fitting.
Butt weld pipe fittings are most commonly available in carbon steel, stainless steel, nickel alloy, aluminum and high yield material. High yield butt weld carbon steel pipe fittings are available in A234-WPB, A234-WPC, A420-WPL6, Y-52, Y-60, Y-65, Y-70. All WPL6 pipe fittings are annealed and are NACE MR0157 and NACE MR0103 compatible.
Materials & Specifications
| Material | Grade |
|---|---|
| Carbon Steel | WPB, WPC, WPL6 |
| Chrome Moly | WP5, WP9, WP11, WP12, WP22 |
| Stainless Steel | 304/304L, 316/316L, 304H, 316H, 309, 310S, 317L, 321/321H, 347/347H, 904L, DUPLEX 2205 / SUPER DUPLEX 2507 |
| High Yield Carbon Steel | WPHY42, WPHY52, WPHY65 |
| Nickel Alloys | Alloy 20, 200, 201, 400, 600, 625, 800H/HT, 825, 254SMO, AL6XN, C276, C22, B3, HAST-X |
- Standard Grades: Carbon, Stainless, Chrome Moly, High Yield, Low Temperature, Aluminum
- Types: Elbows, Tees, Reducers, Caps, Stub Ends, Crosses, Laterals, Olets, Return Bends
- Sizes: Standard 1/2″ to 48″ (special order larger O.D. fittings)
- Wall Sizes: Schedule 20 thru XXH, and Special Wall Sizes
- Specialty Items: 3D & 5D Bends, Galvanizing, 100% X-ray Testing
Forged Steel buttweld fittings are manufactured in accordance with ANSI / ASME B16.9.
Manufacturing standards of welded fittings
| Standard | Grade |
|---|---|
| ASME | ANSI B16.9, ANSI B16.28, MSS-SP-43 |
| DIN | DIN2605, DIN2615, DIN2616, DIN2617, DIN28011 |
| EN | EN10253-1, EN10253-2 |
| ASTM A403 – ASME SA403 | Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings |
| ASME B16.9 | Factory-Made Wrought Fittings Buttwelding |
| ASME B16.25 | Buttwelding Ends |
| ASME B16.28 | Wrought Steel Short Radius Elbows and Buttwelding Returns |
| MSS SP-43 | Wrought and Fabricated Butt-Welding Fittings for Low Pressure, Corrosion Resistant Applications |
Recommended Butt Weld Pipe Fittings
We will help you put together your entire project and ship it to your closest port.
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12D Pipe bending -
15CrMoG bending -
180 Degree pipe bending -
316 Stainless steel elbow -
3D Pipe bending -
5D Pipe bending -
7D Pipe bending -
A234 WPB large diameter pipe cap -
A403 WPS304L Stainless stub end -
ASME SA335 P91 elbow -
ASME/ANSI B16.9 pipe end caps -
ASTM A234 WP11 eblow -
ASTM A234 WP22 elbows -
ASTM A234 WPB Pipe Fittings -
ASTM A420 WPL6 Elbow -
Barred Tee -
Big diameter elbows -
Butt weld pipe tee -
Carbon steel caps -
Carbon steel elbow -
Carbon steel return U bend -
Carbon steel stub end -
Elliptical head -
Equal cross
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 forged (through multiple process) to get he shape of elbows, tees and reducers etc.
Fittings may be made to special dimensions, sizes,shapes, and tolerances by agreement between the manufacturer and the purchaser.Welding Bevel acc. to
- ASME B16.9, Factory-Made Wrought Steel Buttwelding Fittings
- ASME B16.28, Buttwelding Short Radius Elbows and Returns
- ANSI/ASME B16.25, Buttwelding Ends
- MSS SP-97, Socket Welding, Threaded, and Buttwelding Ends
ASME B16.25 sets standards for the preparation of the ends of components that need to be welded together.
Cut square or slight chamfer, at manufacturer’s option for :
- t ≤ 0.19” carbon steel or ferritic alloy steels
- t ≤ 0.12” austenitic alloy steels
The allowable pressure ratings for fittings designed in accordance with the standard ASME B 16.9–1993 may be calculated as for straight seamless pipe in accordance with the rules established in the applicable section of the ASME B 31 codes for pressure piping.
- are strong and leak-proof
- minimize the pressure drops and the turbolence along the pipeline
- have a long service life
A seamless butt weld pipe fitting is made directly from a section of seamless pipe material, by applying heat and pressure to transform pipe directly into an elbow or other shape.
A seamless fitting has no welded parts by itself, a characteristic demanded in some critical applications.
By comparison, a regular butt weld fitting has one, two or more welds, depending on dimension, shape and manufacturing method.
A pipe fitting is defined as a part used in a piping system, for changing direction, branching or for change of pipe diameter, and which is mechanically joined to the system.
There are many different types of fittings and they are the same in all sizes and schedules as the pipe.
- ASTM: A234 WPB
- ASME: B16.9, B.11
- NACE: MRO175
- MSS: SP-83, SP-95
- (Fittings are also defined by their material grade and whether they are welded or seamless.)
- Diameter refers to outside diameter of a pipe or fitting.
- The North American standard is known as Nominal Pipe Size (NPS). The International Standard is known as Diameter Nominal (DN). Pipes and fittings are actually made in similar sizes around the world: they are just labeled differently.
- From ½ in to 12 inch “Nominal Pipe Size”, outside diameters are slightly larger than indicated size; inside diameters get smaller as schedules grow.
- From 14 in and larger “Nominal Pipe Size”, outside diameters are exactly as indicated size; inside diameters get smaller as schedules grow.
- As with other North American standards (inch, foot, yard, mile, …), many pipe standards (diameters up to 12 inch and wall thickness) are based on historical precedents (a toolmaker’s dies during US Civil War) rather than a “scientific” method.
PVF means Pipe, Valve and Fittings, and is widely used as short-hand to describe this industry.
PVFs can be made in a variety of metals or plastics.
Manufacturers typically specialize in special types of materials; distributors can carry narrow or very broad product lines.
Buttweld fittings and their applications
Pipe fittings come in many forms with the most common being threaded fittings, socket weld fittings and buttweld fittings. This blog will explore the advantages of all three types, but especially the advantages of buttweld fittings and their applications.
- Chemical / Petrochemical
- Municipal
- Food, Beverage, and Dairy
- Oil and Gas
- Power
- Process Instrumentation
- Pulp and Paper
- Semiconductor
- Marine & dredging
- Sanitation
- Flanges Used in Piping Systems
- Irrigation
- Residential
- Road & highway construction
- Ventilation etc.
Pipe fittings are essential parts of pipelines as they allow for the following:
- A change in direction for the liquid flowing through the pipes
- Branching of the pipe to allow the liquid to flow in two separate directions
- A reduction in pipe diameter
- The attachment of auxiliary equipment
- The end of the pipeline
All the buttweld fittings supplied by Special Piping Materials are designed in accordance to ASME standards.
Advantages:
Buttweld fittings can withstand pressures and temperatures in very harsh environments. They are generally considered to be the most robust welding fixture, no matter what industry it is required for. However, they do take a considerable time to fit and a highly skilled installer is required to weld them correctly on site.
- Welded connection offers a more robust, a stronger and a more leak-proof piping connections.
- The nature of the continuous metal structure provides added strength to the overall piping system.
- The smooth inner surface and gradual directional changes provide a seamless flow, thus minimising pressure drops and turbulence inside the pipe.
- Provide the option of various different turn radiuses due to the manufacture of Short Radius fittings, Long Radius fittings and 3R Elbows.
- They are cost effective compared to the counterpart fittings in the threaded or socket weld varieties.
- They have a long service life and are cost effective to purchase and deploy.
- Buttweld fittings can withstand corrosion and erosion more effectively than its socket weld and threaded equivalents.
- A welded system uses comparatively less space that the other alternatives.
How a Butt Weld Fitting is Made?
A butt weld pipe fitting is made by the process of hot forming that includes bending and forming to shape. The starting material of butt weld fitting is a pipe that is cut to length, heated and molded into specific shapes by means of dyes. Heat treatment is also done to remove residual stresses and obtain desired mechanical properties.
These fittings are produced using latest technology, ensuring excellent strength and long service life. The process needs a lesser amount of heat treatments to ensure better physical properties.
The series of steps involved in the manufacturing Process of Buttweld Fittings are given in a detailed view below:
Annealing :
Annealing is also known as heat treatment, which plays an active role in the production. In this step, the tubes are carried out in fully automated and conveyor to heat them at certain temperature. Once the tubes get heated, they immediately quench in water.
Straightening :
The tubes are straightened with the help of straightening machine to provide a high degree of straightness in this step.
Pickling :
The process of Pickling refers to the removal of high temperature scale and adjacent low chromium layer of metal from the surface of stainless steel.
Passivation :
Passivation is the process of treating the surface of stainless steels in order to eliminate the contaminants from the metal. The process also helps in promoting the formation of a continuous passive film on a freshly created surface.
Polishing :
The final step, is named as Polishing that reflects the wonderful quality, high aesthetic & hygienic value and high durability of buttweld fittings. Polishing is a essential step to gain excellent features for meeting the varied demands of clients