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Butt weld pipe fittings

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.

What are the benefits of Butt Welded 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.

Materials & Specifications

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

Forged Steel buttweld fittings are manufactured in accordance with ANSI / ASME B16.9.

We will help you put together your entire project and ship it to your closest port.

Common type of Butt weld pipe fittings

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 forged (through multiple process) to get he shape of elbows, tees and reducers etc.

Long radius (LR) elbows

Long radius elbows Long Radius (LR) Elbows – radius is 1.5 times the pipe diameter

Short radius (SR) elbows

Short radius elbows Short Radius (SR) Elbows – radius is 1.0 times the pipe diameter

Bending
API Pipe bend
Pipe bend can be made of variety materials,like carbon steel,alloy steel,stainless steel,low temperature steel or high performance steel,etc.
Tee
Tees straight and reducing
We can provide seamless tube tees and welding tube tees,which can also be divided into straight tees and reducing tees.
Cap
Carbon steel end caps
Pipe cap is usually used for protecting the end of pipe and other fittings,so the shape is disigned according to the shape of pipe line.
Reducer
ASTM A234 WPB Concentric Reducer
Pipe reducer are tube fittings that are widely used in a number of industries in order to providing greatest connection flexibility in connecting fractional tubes in various installations.

Frequently asked questions

Pipe Fittings End Beveling
Pipe elbows

Fittings may be made to special dimensions, sizes,shapes, and tolerances by agreement between the manufacturer and the purchaser.

Welding Bevel acc. to

Bevelled Ends

The ends of all buttweld fittings are bevelled, exceeding wall thickness 4 mm for austenitic stainless steel, or 5 mm for ferritic stainless steel. The shape of the bevel depending upon the actual wall thickness. This bevelled ends are needed to be able to make a "Butt weld".

Welding Bevel acc.to ASME / ANSI B16.9 and ASME / ANSI B16.28

ASME B16.25 covers the preparation of buttwelding ends of piping components to be joined into a piping system by welding. It includes requirements for welding bevels, for external and internal shaping of heavy-wall components, and for preparation of internal ends (including dimensions and dimensional tolerances).

Our in-hourse R&D team developed bevel ends equipment are good using in thickness 2mm to 20mm pipe fittings, guarantee high efficiency and high quality.

End bevel

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These weld edge preparation requirements are also incorporated into the ASME standards (e.g., B16.9, B16.5, B16.34).

ASME B16.25 (BUTT WELD ENDS)

ASME B16.25 sets standards for the preparation of the ends of components that need to be welded together.

Asmeb1625

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
BENEFITS OF WELDED FITTINGS

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
End connections

There are four different type of connections that are used for fittings:

  • Butt Weld Fittings – Probably the most common type of fitting. They are easily manufactured and are easily installed. Butt weld fittings can be connected directly to each other. This is called fitting make up.
  • Flanged Fittings – Flanged fittings are piping components where the flange is an integral component of the fitting. These are most often used in water treatment applications or lined piping where welding would be destructive to the liner.
  • Socket Weld Fittings – These fittings have a socket weld connection on each end. They might be used for smaller diameter piping. These fittings utilize a single fillet weld to join the piping with the fitting.
  • Threaded Fittings – Threaded fittings are generally four inches and smaller. The reason for this size constraint is the pipe end needs to be threaded with a male type connection and die sizes are unobtainable in the larger diameters.
Fitting Weights

ASME buttweld fitting specifications do not specify weights for fittings.

Weights quoted in the tables on this page are based on manufacturers information and should be considered as approximate and provided as a guide only (fitting weights can vary considerably between manufacturers due to differences in construction).

Buttweld Fittings general

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.

Three groups:

Fittings are divided into three groups:

  • Buttweld (BW) fittings whose dimensions, dimensional tolerances et cetera are defined in the ASME B16.9 standards. Light-weight corrosion resistant fittings are made to MSS SP43.
  • Socket Weld (SW) fittings Class 3000, 6000, 9000 are defined in the ASME B16.11 standards.
  • Threaded (THD), screwed fittings Class 2000, 3000, 6000 are defined in the ASME B16.11 standards.
Applications & markets

Fittings are used wherever liquids, gases, chemicals and other fluids are created, processed, transported, or used.

Range of industries is very wide, as shown below:
  • Energy related.
    Oil and gas industries, including upstream (exploration and production), midstream (transportation by ships, pipeline, rail, trucks; storage and wholesale) and downstream (refining into fuels or chemicals; marketing and distribution). Power plants using fossil or nuclear fuels. Geothermal energy for harnessing heat from the earth.
  • Food and beverage production.
    From basic ingredients to elaborate desserts. From milk, to juices and other beverages. Cold chain to keep produce fresh, drinks and frozen foods at a set temperature. Desalination plants to transform seawater into drinking water for arid areas and various tropical islands.
  • Pharmaceuticals and biotech production.
    Medicines and vaccines that treat illnesses and help restore bodies and minds to their top conditions.
  • Semiconductor manufacturing:
    Microchips that go into all electronics, including smartphones, tablets, computers, television sets, telecom networks …
  • Pulp and paper production.
    Newsprint, glossy paper, cardboard boxes, books, writing paper
  • Production of construction materials and plastics. From roofing materials, to glassmaking for windows, to copper wiring for transporting electricity, and various plastics throughout houses and office buildings.


FITTING SIZES AND DIMENSIONS

How are pipe fittings measured ?

Pipe fittings are measured by their diameter, wall thickness (known as “schedule”), and shape or configuration.

  • (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.

What does “schedule” mean for pipe fittings ?
What is schedule 40, sch80 ?

As the main function of the pipes is to carry fluid under pressure therefore their internal diameter is their critical dimension. This critical dimension is referred to as the nominal bore (NB). Obviously, for pipes containing pressurised fluids the wall thickness, and by implication the pipe’s strength, is important. Wall thickness is expressed in “schedules“, referred to as pipe schedules. The pipe schedule is abbreviated as SCH.

Nominal Pipe Size (NPS) is a North American set of standard sizes for pipes used for high or low pressures and temperatures.

  • Schedule, often shortened as sch, is a North American standard that refers to wall thickness of a pipe or pipe fitting. Higher schedules mean thicker walls that can resist higher pressures.
  • Pipe standards define these wall thicknesses: SCH 5, 5S, 10, 10S, 20, 30, 40, 40S, 60, 80, 80S, 100, 120, 140, 160, STD, XS and XXS. (S following a number is for stainless steel. Sizes without an S are for carbon steel.)
  • Higher schedules are heavier, require more material and are therefore more costly to make and install.
Why are fittings sometimes thicker and heavier than pipes to which they are connected ?

Fittings are sometimes thicker than their connecting pipes to meet performance requirements or due to manufacturing reasons.

  • Due to fitting geometry, stress is very different when compared to a pipe.
  • Using extra material is often necessary to compensate for such additional stress, especially for tees and tight curve elbows.
  • Fitting manufacturers may not always stock plates or pipes for all metal grades or sizes.
  • When responding to an order, manufacturers always use the right metal or alloy, but sometimes made with next-higher available plate or pipe size while still respecting specified inside diameters.
What does 45 SR or 90 LR mean for pipe fittings ?

By default, there are 5 opportunities, the 45°, 90° and 180° elbows, all three in the "long radius" version, and in addition the 90° and 180° elbows both in the "short radius" version.

  • 45 and 90 refer to angles for changing direction of pipe flows: 45 degrees or 90 degrees. Most elbows are 45˚ or 90˚.
  • SR means Short Radius; LR means Long Radius. Centerline radius of long radius (LR) elbows is smoother than of short radius (SR).
  • In SR fittings, radius equals nominal diameter size. A 6 inch pipe will have a 6 inch radius center-to-end, giving it a sharp curve.
  • In LR fittings, radius equals 1.5x nominal diameter size. A 6 inch pipe will have a 9 inch centerline radius, for a smoother curve than SR.
What is the difference between a 3R and a 3D elbow?

There is no difference between 3R and 3D.

  • Both have a centerline radius of three times the nominal diameter size.
  • Both have a smoother curve than an SR or LR.
  • (In fittings, 3D does not refer to modeling software or screens.)
What does 3D or 6D mean for pipe fittings ?

Larger numbers have smoother curves.

  • Centerline radius is calculated based on diameter and number that precedes it.
  • For example, a 10″ 6D has a 60″ centerline radius.
  • Smoother curves are often used for applications with higher pressure, abrasion or corrosion.
What is the difference between concentric and eccentric reducers ?

A reducer is the component in a pipeline that reduces the pipe size from a larger to a smaller bore (inner diameter).

What is a lateral pipe fitting ?

lateralA lateral separates one line into two; the second line branches at a 45˚ angle.

The WYE have two branch pipes at a 45 degree angle between them,and the two branch pipes are symmetrical to the centerline of the inflow pipe which means the two outflow direction are both at 22.5 degree to the inflow direction.

What is a seamless butt weld fitting?

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.

No weld means less risk of weld yield and porosities.

What is PVF?

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.

Differentiate between SCH 40 & True Schedule 40

Pipe fittings 12 inch or larger require specifying if fitting is standard wall (most commonly referred to sch 40) or a true schedule 40 is required.

This is needed since schedule 40 do NOT correspond to standard wall for pipe sizes 12” and bigger. A true sch 40 will be thicker than standard wall for pipe fittings 12” or bigger.

Differentiate between SCH 80 & True Schedule 80:
For pipe sizes 10 in and above, sch 80 do NOT correspond to XH. Customer must specify if they want SCH 80 or XH wall.

What is ASTM A420 WPL6 pipe fittings?

The ASTM A420 WPL6 steel pipe fittings means the butt welding pipe fittings whose material is ASTM A420 grade WPL6.ASTM A420 is standard specification for piping fittings of wrought carbon steel and alloy steel for low-temperature service.So A420 WPL6 fittings are specially used in low temperature conditions.

Chemical composition of A420 WPL6 material:
Grade C Mn P S Si
WPL6(1)(2) 0.3 0.60-1.35 0.035 0.04 0.15-0.30
Mechanical properties of A420 WPL6 material:
Tensile Requirements WPL6
Tensile Strength
min, ksi [MPa]
60-85[415-585]
Yield Strength
min, ksi [MPa]
35[240]

ASTM A420 WPL6 pipe fittings are one kind of butt welding pipe fittings,they are commonly produced from the steel pipes of ASTM A333 Grade 6.This material should be arranged the charpy V impact test in temperature of -46℃,to make sure it can work in a lower temperature service,for example in cold weather,winter or deep-sea water offshore projects.



About Sunny Steel

Our team are highly trained and experienced in servicing and producing all types of steel supplies. Whether you've got a large construction project, or need parts for industrial machinery, our team of steel fabrication consultants will ensure that your project is provided with the parts you need, when you need them.

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