What are buttweld fittings in piping? Buttweld fittings are pipe fittings used to change the pathway of a pipeline (elbows), reduce/increase the pipe bore size (reducers), branch (tees, cross) or blind a pipeline (butt weld cap). ASME B16.9 (and MSS-SP 43) Buttweld fittings are used for piping systems above 2 inches in diameter, whereas socket weld and threaded fittings are used for smaller size pipes (ASME B16.11).

管道中的对焊配件是什么？对焊管件是用于改变管道路径（弯头）、减小/增大管道孔径（异径管）、支管（三通、四通）或封闭管道（对焊帽）的管件。ASME B16.9（和MSS-SP 43）对焊管件用于直径大于2英寸的管道系统，其中承插焊接和螺纹管件用于较小尺寸的管道（ASME B16.11）。

BUTTWELD FITTINGS IN PIPING管道中的对焊配件

Buttweld fittings are available in multiple shapes (elbows, tees, reducers, crosses, caps,
对接焊接配件有多种形状（弯头、三通、异径管、四通、管帽、，stub ends
翻边短节),
),material grades
材料等级 (carbon, high-yield carbon, low-alloy, stainless, duplex, and nickel alloys), and
（碳、高屈服碳、低合金、不锈钢、双相合金和镍合金），以及dimensions
尺寸 (2 to 24 inches in seamless execution, and welded for larger pipe sizes).
（2至24英寸，无缝执行，并为更大的管道尺寸焊接）。

The key specifications for buttweld fittings are the
对焊配件的关键规格是ASME B16.9
ASME B16。9 (carbon and alloy fittings) and the
（碳和合金配件）和MSS SP 43
MSS SP 43 (that integrates ASME B16.9 for stainless steel, duplex, and nickel alloy BW fittings).
（整合了ASME B16.9，适用于不锈钢、双相和镍合金对焊管件）。

Butt welding fittings have the following benefits
对焊配件具有以下优点

· ·allow strong, and leak-proof, piping connections
允许牢固、防漏的管道连接

· ·minimize pressure drops and the turbulence inside the pipeline
将管道内的压降和湍流降至最低

· ·have a long service life
使用寿命长

· ·are rather cheap to purchase and deploy
购买和部署成本相当低

For piping systems below 2 inches in diameter,
对于直径小于2英寸的管道系统，socket weld and threaded
承插焊接和螺纹连接 (forged) fittings are generally used (ASME B16.11).
通常使用（锻造）管件（ASME B16.11）。

BUTTWELD ELBOW 45/90/180 DEG.对焊弯头45/90/180度。

ASME B16.9 buttweld elbows are manufactured in a wide range of dimensions (combinations of outside diameter and wall thickness) to fit
ASME B16。9对焊弯头的制造尺寸范围广泛（外径和壁厚的组合），以适合ASME B36.10 and ASME B36.19
ASME B36。10和ASME B36。19 carbon, alloy and stainless steel pipes of any size between 2 and 48 inches (and above).
2至48英寸（及以上）的任何尺寸的碳钢管、合金钢管和不锈钢管。

Buttweld elbows below 24 inches in diameter are produced by cutting, heating and bending seamless steel pipes; pipe elbows of larger sizes are manufactured, instead, from welded pipes or steel plates.
直径在24英寸以下的对焊弯头由切割、加热和弯曲无缝钢管制成；更大尺寸的弯管由焊接管道或钢板制成。

The three most common types of elbows in piping are the 45, 90, and 180 degrees (or return elbow), as shown in the image:
管道中最常见的三种弯头类型是45度、90度和180度（或回流弯头），如图所示：

Some special types of pipe elbows are:
一些特殊类型的弯管包括：

· ·reducing elbow: a pipe connector with an inlet and an outlet in two different bore sizes is used instead of the combination of a standard elbow and concentric reducer.
异径弯头：使用具有两种不同孔径的入口和出口的管道接头，而不是标准弯头和同心异径管的组合。

· ·mitered elbow: large size elbow assembled by joining steel plates
斜接弯头：通过连接钢板组装的大尺寸弯头

SHORT VS LONG RADIUS ELBOW短半径弯头与长半径弯头

The center to face distance of a long radius pipe elbow is always 1.5 times the nominal pipe size, whereas, for a short radius pipe elbow, the center to face distance is equal to the nominal pipe size.
长半径管道弯头的中心到面距离始终是标称管道尺寸的1.5倍，而对于短半径管道弯头，中心到面距离等于标称管道尺寸。

Example:
例子：

· ·For a 4 inches long radius (LR) butt weld elbow, the center to face distance is 4 x 25.4 x 1.5 = 152.4 mm;
对于4英寸长的半径（LR）对焊弯头，中心到面的距离为4 x 25.4 x 1.5=152.4 mm；

· ·For a short radius butt weld elbow, the center to face distance is instead 4 x 25.4 x 1 = 101.6 mm. Short radius pipe elbows are available only for the 90 and 180-degree configuration (and not for the 45 degrees); instead, long radius elbows are available for all degrees.
对于短半径对焊弯头，中心到面的距离为4 x 25.4 x 1=101.6 mm。短半径管弯头仅适用于90度和180度配置（不适用于45度配置）；相反，长半径弯头适用于所有角度。

PIPE ELBOW MANUFACTURING PROCESS弯管制造工艺

Buttweld elbows 45 and 90 degrees can be manufactured in different ways, the main ones are the “mandrel process” and the “cold forming” (other methods are the elliptical forming and the double-seam welding method).
45度和90度对焊弯头可以用不同的方法制造，主要有“芯轴法”和“冷成型”（其他方法有椭圆成型和双缝焊接法）。

Mandrel Process
心轴工艺

Cold forming
冷成型

Source: TK Bend
来源：TK Bend

PIPE BENDS弯管

A pipe bend is a generic term to indicate a fittings that changes the direction of the piping system (technically, elbows are pipe bends too but of a standardized type in terms of angle degree and direction). The term “pipe bend” refers to a fitting that offsets the direction of the pipe works, without specifying the actual degree and direction.
弯管是一个通用术语，表示改变管道系统方向的管件（从技术上讲，弯头也是弯管，但在角度和方向方面是标准类型）。术语“管道弯头”是指偏移管道工程方向的管件，但不指定实际角度和方向。

Pipe bends are manufacturing by twisting a pipe or a tube using a bending machine, with an hot or a cold forming process. Pipe bends are economical ways of making pipe works layouts decreasing the number of other pipe fittings used.
弯管是使用弯管机通过热成型或冷成型工艺扭转管道来制造的。弯管是制作管道工程布局的经济方法，可以减少使用的其他管件的数量。

BUTTWELD TEE对焊三通

EQUAL TEE等径三通

An equal tee, otherwise called straight tee, is a buttweld fitting used to branch a pipeline, or any other pipework, at 90 degrees.
等径三通，也称为直三通，是一种对接焊接管件，用于在90度处分支管道或任何其他管道工程。

A pipe tee is defined “equal” when the bore size at the run and branch sides have the same diameter. An equal tee is, therefore, used to connect two pipes of the same nominal diameter.
当管路侧和支管侧的孔径相同时，三通被定义为“相等”。因此，使用等径三通连接两个公称直径相同的管道。

Equal tees are available in sizes from half an inch to 48 inches (or larger) and in seamless and welded execution (seamless up to 24 inches, welded for tee sizes above 24 inches).
尺寸从半英寸到48英寸（或更大）的等径三通以及无缝和焊接执行（无缝至24英寸，对于尺寸超过24英寸的三通进行焊接）。

Buttweld tees are manufactured according to ASME B16.9 (carbon and alloy) and MSS SP 43 (stainless steel and nickel alloy).
对焊三通根据ASME B16制造。9（碳和合金）和MSS SP 43（不锈钢和镍合金）。

REDUCING TEE异径三通

A reducing tee features a smaller bore size at the branched pipe side (generally 2/3 sizes smaller).
异径三通在支管侧的孔径较小（通常较小2/3）。

In case a larger bore size reduction is necessary, then a reinforced branch connection (such as a
如果需要减小更大的孔径，则需要加强支管连接（例如Weldolet
焊接支管台) shall be preferred to prevent turbulence and have a smoother flow reduction.
)应优先防止湍流，并具有更平滑的流量减少。

The standard dimensions and tolerances of equal and reducing pipe tees are covered by the ASME B16.19 specification (carbon and alloy steel) and by the MSS SP 43 spec (for stainless steel and nickel alloys tees).
ASME B16涵盖了等径管和异径管三通的标准尺寸和公差。19规范（碳钢和合金钢）和MSS SP 43规范（适用于不锈钢和镍合金三通）。

BARRED TEE条纹T恤

A barred tee is a special type of (equal) tee used for pigging operations (reducing barred tees do not exist, as the pig would not pass through the reduced area anyway).
带杆三通是用于清管作业的特殊类型（同等）三通（不存在异径带杆三通，因为清管器无论如何都不会通过异径区域）。

A barred tee features a welded restriction on the branch pipe side that prevents the pig from flowing from the run pipe into the branched pipe.Such barred restriction is welded on the internal side of the fitting and looks like a steel cage.
有杆三通在支管侧具有焊接限制，防止清管器从运行管道流入支管。这种障碍限制焊接在配件的内侧，看起来像一个钢笼子。

PIPE TEE MANUFACTURING PROCESS三通制造工艺

Cold forming is the most used manufacturing process for seamless buttweld tees, as illustrated below. Other methods are the single or double seam welding process.
冷成形是无缝对焊三通最常用的制造工艺，如下图所示。其他方法有单缝或双缝焊接工艺。

Source: TK Bend
来源：TK Bend

BUTTWELD CROSS对接焊四通

A Butt weld cross fitting is used when a double branch at 90 degrees is required, which is a rather rare need.
当需要90度的双支管时，使用对接焊接交叉管件，这是一种非常罕见的需要。

ASME B16.9 and MSS SP43 define the pipe cross dimensions and tolerance. There are no specific limitations in terms of available sizes and schedules for butt weld crosses.
ASME B16。9和MSS SP43定义了管道交叉尺寸和公差。对焊四通的可用尺寸和时间表没有具体限制。

BUTTWELD REDUCERS对焊异径管

CONCENTRIC REDUCER同心异径管

The open ends of a concentric reducer are aligned and centered one to the other. Generally, this type of pipe reducer is used to modify the bore size of the pipeline by two (maximum three) measures, to avoid an excessive pressure drop in the pipeline.
同心异径管的开口端彼此对齐并居中。通常，这种类型的减径管用于通过两种（最多三种）措施修改管道的孔径，以避免管道中的压降过大。

If a larger reduction is needed, then a sequence of reducers shall be used to have a smooth and gradual adjustment of the pipeline bore size (vs. a drastic change).
如果需要更大的减少量，则应使用一系列减少器来平滑、渐进地调整管道孔径（与剧烈变化相比）。

For small bore size reductions,
对于小孔径减小，reducing flanges
异径法兰 may be an alternative to buttweld reducers.
可替代对焊异径管。

ECCENTRIC REDUCER偏心异径管

The open ends of an eccentric reducer are in an “offset” position one to the other.
偏心减速器的开口端彼此处于“偏移”位置。

Eccentric reducers are used, generally, for pipelines installed in a horizontal position (whereas concentric reducers are used for pipelines installed vertically or for the inlets of suction pumps, as top flat eccentric reducers).
偏心异径管通常用于水平安装的管道（而同心异径管用于垂直安装的管道或吸入泵的进口，作为顶部平面偏心异径管）。

TOP AND BOTTOM FLAT ECCENTRIC REDUCER
上下平偏心异径管

Eccentric reducers can be top flat (“TF”) or bottom flat (“BF”).
偏心异径管可以是顶部平的（“TF”）或底部平的（“BF”）。

The bottom flat eccentric reducer type is used for pipe-racks (the bottom of the reducer is flat and at the same level of the bigger sized run pipe), while the top flat pipe reducer type is used at the inlet of piping suction pumps as shown in the image below (this setup prevents the formation of vapor traps in the pipeline):
底部扁平偏心异径管类型用于管架（异径管底部扁平，与较大尺寸的运行管道处于同一水平），而顶部扁平异径管类型用于管道吸入泵的进口，如下图所示（此设置可防止管道中形成蒸汽捕集器）：

PIPE CAP MANUFACTURING PROCESS管帽制造工艺

The manufacturing process of caps starts from steel plates that are cut and shaped with a cold forming procedure:
盖的制造过程始于通过冷成型程序切割和成型的钢板：

Source: TK Bend
来源：TK Bend

SEAMLESS VS WELDED BW FITTINGS无缝对焊对焊管件

Butt weld fittings are available in seamless and welded execution (seamless for bore sizes below 24 inches, welded for sizes above 24 inches).
对焊配件有无缝和焊接两种形式（孔径小于24英寸时为无缝，尺寸大于24英寸时为焊接）。

Seamless buttweld fittings have no seam welds and are therefore considered superior to welded BW fittings (a weld is always a weak point on the metal, prone to corrosion).
无缝对焊配件没有焊缝，因此被认为优于焊接对焊配件（焊缝始终是金属上的弱点，容易腐蚀）。

Seamless BW fittings are manufactured by cutting, heating and shaping
无缝对焊管件通过切割、加热和成型制造seamless pipes
无缝管 into desired forms. Welded buttweld fittings have one, two or more welds, depending on the dimension, the type of fitting and the manufacturing process adopted by the mill.
转化为所需的形式。焊接对焊配件有一个、两个或多个焊缝，这取决于尺寸、配件类型和工厂采用的制造工艺。

BUTT WELD FITTINGS MANUFACTURERS对焊配件制造商

· · Hangrui
温州航锐管业有限公司

· ·APP/CB&I
应用程序/CB&I

· ·Bassi Luigi
巴西·路易吉

· ·Canadoil
卡纳多尔

· ·Close Bend
闭合折弯

· ·Colonial Machine
殖民机器

· ·Erne Fittings
Erne配件

· ·Ezeflow
Ezeflow公司

· ·Hackney-Ladish
哈克尼·拉迪什

· ·Houston Pipe Benders
休斯顿弯管机

· ·IRC Spa
IRC水疗中心

· ·Mills Iron Works
米尔斯钢铁厂

· ·OMR Raccordi (Officine Meccaniche Righi)
OMR Raccordi（官方麦加尼什里基）

· ·Raccortubi
拉科图比

· ·Steel Forgings
钢锻件

· ·Sungkwang Bend
阳光湾

· ·Tectubi
Tectubi公司

· ·Tenaris
泰纳瑞斯

· ·TK Bend
TK弯管

· ·Tube Forgings of America
美国管锻件