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Introduct of steel pipe elbow fittings
SPECIFICATIONS
Our company has resumed normal production and is ready to welcome customers from all over the world for a series of field visits. Our company has professional equipment for producing carbon steel, alloy steel, and stainless steel pipe fittings, and the quality is strictly in accordance with standards. Welcome your inquiry at any time.
The introduction about elbows
In a pipeline system, an elbow is a pipe fitting that changes the direction of the pipeline. According to the angle, there are three most commonly used types: 45°, 90°and 180°. In addition, according to engineering needs, there are also other abnormal angle elbows such as 60°. The materials of elbows include carbon steel, stainless steel, alloy steel, malleable cast iron, non ferrous metals, plastics and so on. Our company mainly produces carbon steel, alloy steel, and stainless steel pipe fittings.
The type of elbow materials
Carbon steel: ASTM/ASME A234 WPB、20#、Q235
Stainless steel:ASTM/ASME A403 WP 304-304L-304H-304LN-304N
ASTM/ASME A403 WP 316-316L-316H-316LN-316N-316Ti
ASTM/ASME A403 WP 321-321H ASTM/ASME A403 WP 347-347H
Alloy steel: ASTM/ASME A234 WP 1-WP 12-WP 11-WP 22-WP 5-WP 91-WP911、15Mo3 15CrMoV、 35CrMoV
Low temperature steel:ASTM/ASME A402 WPL3-WPL 6, 16Mn, Q345
High performance steel: ASTM/ASME A860 WPHY 42-46-52-60-65-70
Stainless steel:ASTM/ASME A403 WP 304-304L-304H-304LN-304N
ASTM/ASME A403 WP 316-316L-316H-316LN-316N-316Ti
ASTM/ASME A403 WP 321-321H ASTM/ASME A403 WP 347-347H
Alloy steel: ASTM/ASME A234 WP 1-WP 12-WP 11-WP 22-WP 5-WP 91-WP911、15Mo3 15CrMoV、 35CrMoV
Low temperature steel:ASTM/ASME A402 WPL3-WPL 6, 16Mn, Q345
High performance steel: ASTM/ASME A860 WPHY 42-46-52-60-65-70
The production processing flow of seamless elbow
①Receiving inspection of raw material. It is the first compulsory chain to guarantee good quality. The testing items refer to chemical composition, mechanical capacity and metallographic analysis.
② Cutting raw material. Correctly and strictly controlling cutting size and proportion can ensure moderate cost.
③ Hot forming. In this step the raw material will be put on the pushing machine, then getting the elbow blanks. The temperature and speed of hot forming determine the quality of elbow blank. If the quality of blank is very good which can reduce some cost. So it is very necessary to control and record the temperature and speed of hot forming.
④ Sizing. The shape of elbow blanks that got in hot forming process are not very good. So it is necessary to adjust the shape, at the same time inspecting if the quality of adjusted blank is ok or not after sizing.
⑤ Heat treatment. The purpose of heat treatment is to eliminate the stress inside of elbow so that the density is more evenly. Carefully recording the temperature of heat treatment and cooling time are the keys.
⑥ Short blasting. The purpose of short blasting is to remove the rust on the elbow. The size of sandblasting can affect the smooth of elbow surface, if the size is too big will lead to the surface is rough, so it is better to choose small size sand.
⑦ Bevel end machining. The angle of bevel end is different for different standard elbow. Correctly and strictly controlling the machining process to make sure the angle is qualified.
⑧ Coating. Generally the coating is black painting, vanish and anti-rust oil. No matter which type the surface should be smoothly.
The whole production chains are all very important, so the datas of each production step of flange must be recorded in details according to ISO request. It is the guarantee for good quality.
Hot forming is the major process for carbon steel and alloy steel materials, but for stainless steel material according to different sizes and wall thickness there are two production processes hot forming and cold forming.
Generally carbon steel material doesn’t need the heat treatment, but for stainless steel and alloy steel the heat treatment is necessary to enhance the mechanical property.
② Cutting raw material. Correctly and strictly controlling cutting size and proportion can ensure moderate cost.
③ Hot forming. In this step the raw material will be put on the pushing machine, then getting the elbow blanks. The temperature and speed of hot forming determine the quality of elbow blank. If the quality of blank is very good which can reduce some cost. So it is very necessary to control and record the temperature and speed of hot forming.
④ Sizing. The shape of elbow blanks that got in hot forming process are not very good. So it is necessary to adjust the shape, at the same time inspecting if the quality of adjusted blank is ok or not after sizing.
⑤ Heat treatment. The purpose of heat treatment is to eliminate the stress inside of elbow so that the density is more evenly. Carefully recording the temperature of heat treatment and cooling time are the keys.
⑥ Short blasting. The purpose of short blasting is to remove the rust on the elbow. The size of sandblasting can affect the smooth of elbow surface, if the size is too big will lead to the surface is rough, so it is better to choose small size sand.
⑦ Bevel end machining. The angle of bevel end is different for different standard elbow. Correctly and strictly controlling the machining process to make sure the angle is qualified.
⑧ Coating. Generally the coating is black painting, vanish and anti-rust oil. No matter which type the surface should be smoothly.
The whole production chains are all very important, so the datas of each production step of flange must be recorded in details according to ISO request. It is the guarantee for good quality.
Hot forming is the major process for carbon steel and alloy steel materials, but for stainless steel material according to different sizes and wall thickness there are two production processes hot forming and cold forming.
Generally carbon steel material doesn’t need the heat treatment, but for stainless steel and alloy steel the heat treatment is necessary to enhance the mechanical property.
Strictly inspection for each step during the production
Reinspection of raw materials: Chemical analysis, Mechanical property, Metallographic analysis (mainly analysis of grain size), MTC of raw material checking
The pushing and pressing of elbows: The production process of elbows can be divided two types pushing and pressing. The pushing process is to heat and push the pipe with small diameter to get an elbow with slightly larger than its diameter, resulting in severe wall reduction. The pressing process is to press the pipe to get an elbow with same diameter, which is suitable for thick wall products. It also leads wall reduction but is not as severe as the pushing process.
The pushing temperature of elbow: The pushing temperature of the elbow is related to the wall thickness of the material. The thicker the wall thickness, the higher the pushing temperature, and the different materials have different pushing temperatures.
Heat Treatment: The elbow made of carbon steel does not require heat treatment when the pushing temperature is higher than 750 degrees Celsius. Different materials have different heat treatment temperatures. Alloy steel materials and tees (including various materials) must undergo heat treatment to relieve stress. Heat treatment procedure (normalizing+tempering). Mechanical properties cannot be achieved by only tempering without normalizing. Reducing pipes also require heat treatment to relieve stress.
Bevel end and surface treatment: the sequence of the two processes interchanged, it is better to do the surface treatment and then bevel end which makes the pipe surface more beautiful.
Finished product inspection: During testing, samples should be taken from different locations of the pipe fittings for chemical composition and mechanical property testing. At the same time, the diameter and wall thickness of pipe fittings should also be tested.
Non destructive testing/flaw detection: Both methods are used to detect cracks or welds in order to prevent pipe fittings from exploding during use.
The pushing and pressing of elbows: The production process of elbows can be divided two types pushing and pressing. The pushing process is to heat and push the pipe with small diameter to get an elbow with slightly larger than its diameter, resulting in severe wall reduction. The pressing process is to press the pipe to get an elbow with same diameter, which is suitable for thick wall products. It also leads wall reduction but is not as severe as the pushing process.
The pushing temperature of elbow: The pushing temperature of the elbow is related to the wall thickness of the material. The thicker the wall thickness, the higher the pushing temperature, and the different materials have different pushing temperatures.
Heat Treatment: The elbow made of carbon steel does not require heat treatment when the pushing temperature is higher than 750 degrees Celsius. Different materials have different heat treatment temperatures. Alloy steel materials and tees (including various materials) must undergo heat treatment to relieve stress. Heat treatment procedure (normalizing+tempering). Mechanical properties cannot be achieved by only tempering without normalizing. Reducing pipes also require heat treatment to relieve stress.
Bevel end and surface treatment: the sequence of the two processes interchanged, it is better to do the surface treatment and then bevel end which makes the pipe surface more beautiful.
Finished product inspection: During testing, samples should be taken from different locations of the pipe fittings for chemical composition and mechanical property testing. At the same time, the diameter and wall thickness of pipe fittings should also be tested.
Non destructive testing/flaw detection: Both methods are used to detect cracks or welds in order to prevent pipe fittings from exploding during use.
The package types of elbow
| 1 | Plywood pallet | 1. Flange pipe fittings that cannot be boxed shall be packaged using pallets; 2. Foreign trade pallets only use plywood 3. Each product on the tray is fixed in place, and large flanges are fixed with bolts |
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| 2 | Plywood case | 1. Small single products shall be packaged in wooden boxes; 2. Reinforcing strips with basic colors on four sides; 3. External printing of Chinese or English logo and stacking identification; European style bottom plate for export products. |
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| 3 | Carton | 1. Small quantities or express delivery products are packaged in cartons; 2. External printing of Chinese or English logo and stacking identification; 3. The packing shall be tight, and the incomplete parts shall be filled with foam. |
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| 4 | Wrapping film | 1. Use winding film for palletizing products; 2. Tight, uniform and economical packaging; 3. External printing of Chinese or English logo and stacking identification; |
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| 5 | Plastic bag/septa | 1. Single piece plastic bag set for stainless steel pipe fittings; 2. Stainless steel flanges are protected by spacers in layers. |
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The customer received our product and highly recognized the quality, the following new order confirmed.
If you need steel pipe fittings you can contact us Email: mtldsales@metleader.com
If you need steel pipe fittings you can contact us Email: mtldsales@metleader.com