How to Bend Pipe

You can bend pipe and tubing in one of several methods, depending on what you plan to use the bent pipe or tube for. The problem in bending pipe is figuring out where and how much to bend the pipe. While many bending tools come with a set of instructions for figuring out such things as bend allowances and bend deductions, they are often written in a complex manner and assume a knowledge of mathematics that intimidates many users. While it’s not possible to completely eliminate the math, it is possible to plan how to bend a piece of pipe in such a way that figuring the bending angle is simplified and so that the only math needed is simple arithmetic. The method described below is not simple, but with practice, you can master it.

Selecting a Bending Tool

Choose the right bending tools for your needs. There are 6 main bending methods. Each is best suited to a particular type of pipe.

• Ram style bending, also called incremental bending, is usually used for putting large bends in light-gauge metal, such as electrical conduit. In this method, the pipe is held down at 2 external points and the ram pushes on the pipe at its central axis to bend it. Bends tend to deform into an oval shape at both the inside and outside of the bend.
• Rotary draw bending is used to bend pipe for use as handrails or ornamental iron, as well as car chassis, roll cages, and trailer frames, as well as heavier conduit. Rotary draw bending uses 2 dies: a stationary counter-bending die and a fixed radius die to form the bend. It is used when the pipe needs to have a good finish and constant diameter throughout its length.
• Mandrel bending is used to make stock and custom exhaust pipes, dairy tubing, and heat exchanger tubing. In addition to the dies used in rotary draw bending, mandrel bending uses a flexible support that bends with the pipe or tubing to make sure the pipe interior isn’t deformed.
• Induction bending heats the area to be bent with an electric coil, and then the pipe or tube is bent with dies similar to those used in rotary draw bending. The metal is immediately cooled with water to temper it. It produces tighter bends than straight rotary draw bending.
• Roll bending, also called cold bending, is used whenever large bends are necessary in the pipe or tubing, such as in awning supports, barbecue grill frames, or drum rolls, as well as in most construction work. Roll benders use 3 rolls on individual shafts to roll the pipe through as the top roller pushes down to bend the pipe. (Because the rolls are arranged in a triangle, this method is sometimes called pyramid bending.)
• Hot bending, in contrast, is used considerably in repair work. The metal is heated at the place where it is to be bent to soften it.
  

Making a Right Angle Bend

Bend a test pipe at a 90-degree angle. Not only will this familiarize you with how much force you need to apply to operate your bender, but this pipe will serve as a reference for future bends.

• To check the angle of your pipe, lay it against a carpenter’s square with the outer bend facing the corner of the square. Both ends of the pipe should just touch the square’s sides and run parallel to them.

Find the place where the bend in the pipe starts. You should see or feel a small flat spot or distortion at the place where the bend starts and where it ends.

Mark the ends of the bend with a permanent marker. Draw the line completely around the pipe.

 

Lay the pipe against the square again to find the length of the pipe in the bend. 

Note the place on each side of the square where the pipe’s markings touch. These should be the same distance from the inside corner of the square. Add these lengths together.

• If the markings on each end of the pipe bend touch the square at 6 inches (15 cm) from the inside corner of the square, the total length of the bent section of the pipe is 12 inches (30 cm).

Find the place on your bending die where the bend begins. Place the bent tube back in your bender with the die used to bend it and note where on the die the mark on the pipe lines up. Mark this place with a dot of paint or by notching the metal with a file.

• If you have more than one die (for different diameters of pipe), make a test bend for each die, as each diameter will require a different amount of metal to make a 90-degree bend.
• Once you know how much pipe is needed to form the bend, you can calculate how long a piece of pipe you need by adding this figure (called the bend deduction) to the vertical and horizontal l

How to distinguish between pipe elbow and pipe bending

Bends typically have a minimum bending radius of 1.5 times pipe radius (R). If this bending radius is less than 1.5R, it is called Elbow. Reference to any international / industry standard need to be traced. 1.5, 3 and 4.5 R are the most common bending radii in industry.
” All bends are elbows but all elbows are not bends.”
Infact, the pipe is bent to form an elbow.
Elbows are pre-fabricated and are firm in design.
There are issues with bends since the tickness at the bend radius reduces as we bend the pipe.

A pipe bending is typically of the same material and typically a more gentle bend to prevent kinking.

A pipe elbow is also typically a sharp 90 degrees and often is a separate piece.

A bend typically flows smoother since there are not irregular surfaces on the inside of the pipe, nor does the fluid have to change direction abruptly.
The most basic difference of them is the elbow relatively short than bend, R = 1D to 2 D is elbow More than 2D is bend. In the production process, cold bends can use Bending Machine to bend by ready-made straight bend. One-time completed also don’t need second corrosion. But elbow need manufacturers make to order, to do anti-corrosion, order cycle is long. Elbow price is higher than bend. But cost performance is much higher than bend. It is well-known that bend do not have anticorrosive processing is easy damaged, but the price is cheap so are used very much in some demand which not very high engineering.
In the west-east gas transmission of course, cold bends cost is low. elbow need manufacturers make to order, needs corrosion, order cycle is long,but cold bends can use ready-made straight bend by Bending Machine to bend. One-time completed also don’t need second corrosion. The cold bend construction technology need follow oil standard .west-east gas transmission have the enterprise standard,but we can use either elbow nor bend in open area. Sunny Steel Enterprise warn broad customers betweenness elbow and bend performance price is differ ,please carefully choose after consider it.

Industrial Processes
Bending, squeezing, pressing, forging, machining and more

Industries Served
Our pipe elbows are widely used in many industries, such as power generation, petroleum, natural gas, chemicals, shipbuilding, heating, papermaking, metallurgy and so on.

Bimetal Clad Pipe Bend

 
Bimetal Clad Pipe Bend are cast with mold vanishing vacuum suction casting cladding process. Outer of straight pipe is common steel pipe, cladding realized by forming high chromium lining via centrifugal forming technique.

1. Manufacturing Process of Bimetal Clad Pipe and Bend:

Bimetal Clad Pipe and Bend are cast with mold vanishing vacuum suction casting cladding process. Outer of straight pipe is common steel pipe, cladding realized by forming high chromium lining via centrifugal forming technique. Outer of bend uses hot-bending bend and lining is cast with high-chromium cast iron. Bends and other profile sections can be cladded in whole and this process has changed the traditional practice to fabricate bend and other profile sections by drawing polyline without changing flow pattern of material inside piping,greatly reducing conveyance resistance of material.

2. Advantages Compared with Traditional Wear Resistant

Alloy Cast Iron, Alloy Cast Steel, General Clad Steel Pipe and Cast Stone Pipe:

1. Good wear-resistance, giving full play to wear-resistance of high chromium cast iron.
2. Withstanding high pressure:
Bimetal cladding pipe and bend can be used for any pressure rating. Close bonding of outer and lining by adopting special process make cladding interlayer molten-joint to ensure reliable operation.
3. Good mechanical impact and thermal impact resistance property.
4. Convenient in connection for installation:
Bimetal cladding pipe and bend can be cut and welded as you like.

3. Physical Properties of Bimetal Clad Pipe and Bend:

Flexure Strength	Tensile Strength	Elongation	Cross Section Stretch Ratio	Impact Toughness	Hardness of Wearable Layer	Hydrostatic Testing Pressure
MN/㎡	MN/㎡	%	%	J/c㎡	HRC	Mpa
>610	>700	5	5.1	>15	>38	5.6-12.9

Double tube wear resitant tube

Inside material is so wear resistantace to transport more valume concrete. Outside low carbon steel play the role of protection.
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Wear Resistant pipe bend

The Manufacturing Process of Wear Resistant Ceramic Lined Steel Pipe bend:
SHS-ceramic steel pipe and elbow create a new generation of abrasion and corrosion resistant engineering pipeline which are produced in a way of Self-propagating High-temperature Synthetic process.

Wear resistant elbows are composed of three layers: ceramic, intermediate, and steel layers. The ceramic layer is formed by molten alumina at a temperature above 2500 degree.

The molten alumina produced from the reaction Fe2O3+2Al=2Fe+Al2O3 spreads on the inside wall of the steel pipe under the influence of a centrifugal force, then solidifies, so the ceramic layer has high density and smooth surface and bonds to the elbow.

Features of Alumina Ceramic 
Alumina is a cost effective and widely used material in the family of engineered ceramics. Alumina ceramics have been developed and optimized for maximum wear resistance and corrosion resistance. A high density, diamond like hardness,fine grain structure and superior mechanical strength are the unique properties that make it the material of choice for a wide range of demanding applications. Ceramic has uses similar to Cast Basalt but it has greater resistance to wear in high velocity applications and impact resistance in extreme dynamic systems .

Product: Wear Resistant Elbows/Bends

• Size: DN40-DN600
• Wall Thickness: 3-10mm
• Housing Material: Seamless Carbon Steel
• Inner Material: 95% Alumina Ceramic
• Ceramic Thickness: 3 to 6 mm
• Normal Operation Velocity: 20-35m/s
• Normal Operation Temperature: -50---800degree

Obvious performance of wear resistant elbows: 

1. Heat-resistance, -50 - 800 Celsius degree
2. Easy Installation and Anti-Scaling
3. Abrasion-Resistance and hardness, is above 9.0
4. Corrosion-Resistance,10 times of stainless steel pipe
5. Economical Cost, 20-30% lower than that of anti-abrasion alloy steel elbows.

Application Fields 

• Paper Making: For conveying pulp.
• Shipping: For clearing shipping channels and sediment transportation.
• Metal Mines: For conveying tailings, concentrates and backfill minerals.
• Coal Preparation Plants: For conveying dense media, mixture and coal slurry.
• Power Plants: For deashing, deslagging, coal dropping, powder transportation

Wear-resistant Alloy Composite 90 degree pipe bend

Wear-resistant Alloy Composite Pipe bend

 Wear-resistant alloy steel tubes for the base, lined with super wear-resistant alloy by centrifugal casting, metallurgical combine to form a solid body. LFC elbow vacuum casting process. Resistant alloy tube both excellent wear resistance, high temperature resistance and impact resistance, but also has good toughness, excellent thermal shock resistance to mechanical properties, welding performance, easy installation. Especially suitable for high temperature wear cold shock. Such as electric power, metallurgy, coal, mining, cement and other material handling industry. The product is compared with other wear-resistant pipe, long life, cost of investment economy.

Overall mechanical properties

抗弯强度 Flexure strength	抗拉强度 Tensile strength	延伸率 cpecific elongation	断面伸缩率 cross sedtion Stretch ratio	冲出韧性αK Impact toughess	耐磨层硬度 thickness of Wearable Layer	静水压试验压力 Hydrostatic Testing pressure
MN/m²	MN/m²	％	％	J/cm ²	HRC	Mpa
＞610	＞700	5	5.1	＞15	≥50	5.6-12.9

Performance comparison composite wear 16Mn steel pipe and concrete delivery

管型 Tube type	管型 Tube type	使用时间（天） Service period(day)	输送物料（吨） Material transported	磨损程度 attrition rate	提高寿命 improve lifespan
竖直管 vertical tube	16Mn管	10-15	12000/15000	需更换	22倍
	复合耐磨管	355	264000	管口处磨损
弯管 Elbow	16Mn管	25	16000	需更换	12倍
	复合耐磨管	244	192000	2mm
水平管 horizontal tubes	16Mn管	150-170	12000	更换	10.5倍
	复合耐磨管	438	126000	磨损不明显

管型 tube type	管型 tube type	使用时间（天） Service period(day)	提高寿命 improve lifespan
竖直管 Vertical tube	16Mn管	140	2.6倍
	复合耐磨管	368
弯管 Elbow	16Mn管	90	6倍
	复合耐磨管	540
水平管 horizontal tubes	16Mn管	154	2.6倍
	复合耐磨管	400

Wear-resistant alloy composite pipe Features

A good overall performance

    Composite pipe outer wall with steel , lined with high-chromium alloy , the two formed a good metallurgical bond , both high alloy materials for wear and corrosion resistance properties, but also high mechanical strength and less high impact resistance , to solve a single material can be difficult to reconcile the contradictions and abrasion resistance welding , the material play to the best level of performance advantages, the use of safe and reliable.

2 high wear resistance

    The composite wear layer composite pipe of high -chromium alloy , containing about 45% of the organization of the hard carbide M7C3 type , since this structure Ka rod- type carbide , and it has a high toughness ; while Ka macrohardness carbide micro- hardness is high (HV1500-1800), in the wear layer above HRC55 , so good wear resistance .

3 corrosion resistance , high temperature performance

    Since the composition and structural characteristics Ka carbide substrate and the Cr content of the solid solution has a strong heat resistance, corrosion resistance , high temperature or corrosive environment can show good corrosion resistance, wear resistance.

4 advanced, stable composite technology

    The wear-resistant pipe and elbow by LFC vacuum casting composite manufacturing process, namely F casting method , with the manufacturing process of composite wear-resistant pipe has the following characteristics :

    ( 1 ) The process is simple , easy to operate production yield.

    ( 2 ) Since the process is characterized by high precision tooling size , using an inner tube lined with real high vacuum in the tube by suction casting , so the product , the precise size , density is good.

    ( 3 ) using the method of vacuum casting process F resistant alloy composite pipe production and elbow, homogeneous and stable performance. Does not appear , cracks holes and other phenomena .

5 , good thermal shock performance

    Since the inner tube composite wear , thermal expansion coefficient of the outer layer equivalent to a high level and constantly changing rapidly changing conditions occasions inner fragmentation does not occur , the phenomenon of early failure occurred small pipe system running resistance, beautiful appearance beauty .

6 . Transportation, installation and ease of use

    Alloy composite pipe and elbow quick connector or flange can be welded directly mounted . As the fight against high- performance composite pipe , the pipe diversion occurs when a partial plugging free to percussion , arbitrary cutting , unloading change , installation , maintenance is very convenient.

alloy composite wear-resistant pipe applications

 1 , power plants and coal transportation systems, dry ash conveying pipe ;

 2 , Stone Coal power plant systems ;

 3 , the other a powder pneumatic conveying systems ;

 4 , hydraulic transmission systems and larger particle size slag slurry transportation ;

 5, other mining material handling .

Wear-resistant Alloy Composite 90 degree bend

Technical Parameters of 90 degree bend

序 号	公称 通径 DN	复合 外管 D×t	耐磨层 总 壁	总壁厚	实际 内径	弯曲 半径 D	理论 重量 Kg/件
1	100	121*6	12	18	85	3D	31.2
2	100	127*6	13	19	89	3D	36.6
3	125	133*6	13	19	95	3D	40.4
4	125	140*6	13	19	102	3D	44.8
5	125	146*6	14	20	106	3D	51.6
6	125	152*6	14	20	112	3D	56.3
7	150	159*6	14	20	119	3D	61.1
8	150	168*8	14	22	124	3D	75.2
9	150	180*8	15	23	134	3D	91.2
10	175	194*8	15	23	148	3D	107.1
11	175	203*8	15	23	157	3D	117.3
12	200	219*8	16	24	171	2.5D	119.8
13	225	245*8	16	24	197	2.5D	152.0
14	250	273*8	16	24	225	2.5D	190.0
15	275	299*8	17	25	249	2.5D	239.5
16	300	325*8	17	25	275	2.5D	285.0
17	325	351*8	17	25	301	2.5D	332.5
18	350	377*10	17	27	323	2.5D	416.6
19	375	402*10	17	27	348	2D	379.7
20	400	480*10	18	28	370	2D	444.1
21	425	450*10	18	28	394	2D	497.4
22	450	480*10	18	28	424	2D	568.3
23	475	500*10	18	28	444	2D	616.9
24	500	530*10	19	29	472	2D	720.3
25	550	600*10	19	29	542	2D	929.4
26	600	630*10	19	29	572	1.5D	769.1
27	700	720*12	20	30	660	1.5D	1042.6
28	800	820*12	20	32	756	1.5D	1450.7
29	900	920*12	20	32	856	1.5D	1834.2
30	1000	1050*12	20	32	986	1.5D	2475.3