Technology for producing stainless steel flange by

Technology for producing stainless steel flange

With regard to the core of the stainless steel flange head producing method, we based on gb elbow, such as long radius elbow, will be selected first specification, the pipe material is put forward; The hole enlargement ratio, through theoretical calculation, the general hole enlargement rate between 33% and 35%, push back.

And then a series of finishing process, through shot peening processing, remove iron oxide on the surface of the elbow inside and outside, put on both ends of welding groove processing in order to implement. Through the relevant examination, type steel words, after spray paint and packaging, can go to the factory.
Stainless steel flange is made of stainless steel. Stainless steel flange is 304, 316 for the material of all kinds of stainless steel flange, including flat welding flange and butt weld flange and so on. It is by the head or a horn core mandrel, mandrel from fine to coarse, push the system process is a process with a curved hole diameter. Back support, under the section through the mandrel, behind a memorial arch frame to fix mandrel. Outside the core rod, induction coil, there is a heat pipe, heat is good, and then push the pipe under the car, good processing a.

Described above, is 24 “the following quotation for seamless steel tube as raw materials of elbow production methods, namely later than 24” of more than 600 mm, maximum Angle between 2.032 m to 2.80 m. The production process of the stainless steel flange is basically these situations.

Source: Zhejiang Yaang Pipe Industry Co., Limited (

Stainless steel flange various installation by

Low pressure pipeline can use wire stainless steel flange, the use of more than 4 kg pressure welding of stainless steel flange. By sealing point between two pieces of stainless steel flange and bolt fastening. Stainless steel flange have different thickness and different pressure with different bolt.
When, pump and valve and pipeline connection, these local equipment, also made the corresponding stainless steel flange shape, also known as stainless steel flange connection. Where there are two surfaces in the surrounding use of bolt connection closed connection parts at the same time, generally referred to as the “stainless steel flanges,” such as ventilation pipe connections, this kind of parts can be called “stainless steel flange parts”. But this connection is only a partial equipment, such as stainless steel flange and the pump connection, is bad call water pump “stainless steel flange parts”. Relatively small, such as valve can call “stainless steel flange parts”.
Gasket is a kind of can produce plastic deformation, and has certain strength rings made of materials. Most gaskets from non-metallic plate cutting down, or produced by professional factory in accordance with the provisions, the size, the material of asbestos rubber sheet, asbestos board, PE board, etc.; Also useful sheet metal (tin, stainless steel) will be made of asbestos etc. Nonmetal material wrapped metal package cushion; Another with steelskin belt with asbestos tape winding of spiral wound gasket. Ordinary rubber gasket is suitable for the occasion of temperature below 120 ℃; Asbestos rubber gasket suitable for vapor temperature below 450 ℃, the oil temperature is below 350 ℃, pressure is lower than 5 mpa, for general corrosive medium, the most commonly used is acid-proof asbestos board. In high voltage equipment and pipelines, using 10 copper, aluminum, steel, stainless steel type lens or other shaped metal gasket. High pressure washer and sealing surface contact width is very narrow (line contact), processing with gasket sealing surface roughness is higher.

Low pressure small diameter wire stainless steel flange, high pressure and low pressure of large diameter used welding stainless steel flange, stainless steel flange thickness and different pressure connection bolt diameter and the number is different.

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Processing method of stainless steel stamping elbow by

Processing method of stainless steel stamping elbow has a good variety. Many also belongs to the category of processing machinery, use is the most pressing, forging method, roller processing method, rolling rolling method, abscesses, tensile test, bending method, and the combination of processing method. Processing is the organic combination of machining and metal pressure processing.
Forging, swaging machine will be at the end of the pipe or a department shall be rushed out and reduce the diameter, commonly used swaging machine with rotary, connecting rod type, roller type.
In the method of stamping press with core taper pipe expanding to the required size and shape.
Roller method: placement in stainless steel stamping elbow pipe, peripheral with roller and tyre pressure for circular edge processing.
Stamping and welding elbow, it is the use of sheet and tube of the same material for stamping die stamping half ring bend, and then the two half ring group on the welding elbow.
Types and processing technology of stamping elbow first to talk about what types of stamping elbow:
1). Stainless steel stamping elbow bend pipe, contact us for more, is straight into the different bend radius of curvature, such as elbow, elbow etc.;
2). Stainless steel stamping elbow variable diameter pipe, pipe or tube diameter of a department;
3). With side and back cover type volume tube, increasing the tube end strength to the outside of the tube or inside hemming or pipe end sealed tube;
4). Change the cross-section of the pipe fittings, according to the requirements of the circular section into a square, oval, polygon and so on;
5). Fittings with flange and circular edge, the former refers to the inner tube or outer end convex, the latter refers to the pipe or uplift grooves are formed in the circumferential direction of the pipe;
6). Changes of stainless steel stamping elbow thickness, refers to the direction along the tube length to thickness change.

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The production process of seamless elbow by

Rolling seamless elbow materials are tubular billet, round tube embryo through cutting machine cutting the growth degree of billet is about one meter, and the conveyor belt to the furnace heating. Billet are fed into the furnace heating, the temperature is about 1200 degrees Celsius, fuel for hydrogen or acetylene, furnace temperature control is a key problem. Circular tube billet after going through pressure punch wear empty. General is one of the more common punch is tapered roller puncher, this kind of punch high production efficiency, product quality good, large amount of perforated hole enlargement, can wear a variety of pipe fittings.

After perforation, circular tube billet has been three-roll skew rolling, rolling or extrusion. To take off after extruding tube sizing and sizing mill by taper drill bits high-speed steel into embryo punch, form fitting. Pipe diameter by sizing mill bit length to determine the diameter. Pipe after sizing, into the cooling tower, by water spray cooling, pipe after cooling, will be straightening. Pipe by the conveyor belt to the metal detection after straightening machine (or water pressure experiment) for internal inspection. If the steel pipe internal crack, air bubble, will be detected. Seamless elbow pipe fittings quality through rigorous after manual pick. Seamless elbow pipe fittings quality inspection, after spray paint on the serial number, specification, batch number, etc. Seamless elbow and by crane into the warehouse.

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The head size reducing process by

Concentric reducer should not have crack, double skin appearance, wall thickness should be greater than the big diameter end section of the wall thickness. Roundness of eccentric reducer should not be greater than 1% of the corresponding end diameter, and the allowable deviation of plus or minus 3 mm; Centerline should overlap on both ends of the concentric reducer, the eccentric value allowable deviation is + / – 5 mm.

Size reducing forming technology of the head is with the head big end diameter equal to the size of the pipe into the forming die, along the axial direction of tube billet by pressing, shrink along the cavity movement and metal forming. Head size should not have crack, double skin appearance, wall thickness should be greater than the big diameter end section of the wall thickness.

Centerline should overlap on both ends of the concentric reducer, the eccentric reducer value allowable deviation is + / – 5 mm. According to the size of the reducer reducer, divided into the one of pressing or more press forming.

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The advantages of cold pressing stainless steel elbow by

Now stainless steel elbow in general, and as most of the carbon steel elbow is also pushing production system, though the production rate and quality of elbow push system has a good guarantee, but also there will be problems, but cold press will solve many problems. Today, Zhejiang Yaang Pipe Industry Co., Limited share with you about some of the advantages of cold pressing stainless steel elbow.
(1) cold bend of stainless steel products of good quality and beautiful shape, Angle of internal and external GuanBi surface smooth and complete, no defects such as wrinkle and duck mouth.
(2) cold bending Angle and bending radius of the stainless steel elbow is accurate.
(3) the cold pressing of stainless steel elbow pipe wall thinning of the small dish, uniform wall thickness changes.
(4) the stamping elbow small curvature radius, small machining allowance. The material economy, greatly saves the expensive stainless steel pipe. At the same time, the cold pressing of stainless steel elbow
With working hours is a lot less than others, so the production cost greatly reduced.
(5) good concentricity, smaller ovality. Good use inside and outside is milled, and to track positioning, therefore its concentricity

23 5-82 standard according to GB J: pipe bend after thinning allows for a 12.5%. The cold pressing of stainless steel elbow thinning amount for a 5 to 8%, and internal and external wall thickness change is uniform, The sand filling method flame burn bending method of elbow cylindrical wall thinning amount between a 10% to 10%.

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How to test the flange by

How to test the flange

1, the appearance of flange inspection

1-1, forging flange surface should be smooth, can not have forging scars, defects such as cracks.

1 to 2, flange machining surface can not have burrs, harmful scratches and other defects to reduce the flange intensity and reliability.
1-3, RTJ flange sealing surface shall all be item by item, inspection, slot of two sides can not have the crack caused by mechanical technicians, surface defects such as scratches or injured.
2, flange material shall comply with the provisions of the relevant standards, and shall have the factory inspection certificate.
3, flange processing quality should comply with the provisions of the flange standard.
4, flange processing is completed, should be in the tu rust-proof oil seal face, and to prevent scratches and impact.
5, the flange of NDT inspection shall be determined between the user and the manufacturer.
6, flange acceptance rules shall be determined between the user and the manufacturer.
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The production process of carbon steel elbow by

The design and manufacture of carbon steel elbow must be considered when the hardness of the carbon steel elbow, so how to improve the hardness of the carbon steel elbow, through research we found that the carbon steel elbow to heat treatment process, let’s look at some knowledge of the heat treatment on the carbon steel elbow, carbon steel elbow heated to a certain temperature and heat preservation for a period of time, and then make it slowly cooling, called annealing. Hot bend annealing is a heat the steel to the phase change or part of the phase transition temperature, slow cooling after heat preservation heat treatment method. The purpose of annealing is to eliminate tissue defects, improve the organization make composition uniformity and fine grains, increase mechanical properties of the hot pressing elbow, reduce residual stress; Can decrease the hardness at the same time, improve the plasticity and toughness, improve machinability. So before annealing in order to eliminate and improve both the legacy of tissue defects and internal stress, and to prepare for the follow-up process, so the annealing is belong to the intermediate heat treatment, also called heat treatment in advance.
Carbon steel elbow quenching
Quenching is carbon steel elbow heated to above the critical temperature, heat preservation for a period of time, then quickly into the quenching medium, the temperature plummeted, rapid cooling, at the rate of greater than the critical cooling rate, which is mainly composed of martensite and unbalanced heat treatment method of the organization. Can increase strength and hardness of the steel quenching, but to reduce its plasticity. That is commonly used in quenching hardening agent are: water, oil, caustic soda, and salt solution, etc.
Carbon steel elbow is fire

Normalizing is carbon steel elbow heated to above the critical temperature, all made of steel elbow into homogeneous austenitic, and natural cooling method of heat treatment in air. It can eliminate the net cementite hypereutectoid hot-pressing elbow to the hypoeutectoid hot-pressing elbow normalizing can refine crystal lattice, improve comprehensive mechanical properties, low requirements for the parts use the normalized instead of the annealing process is more economic.

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How to identify the material of elbow by

Sulfuric acid immersion stainless steel elbow test can put 302 and 304 and 316 and 317 distinguished. The sample cutting edge through fine grinding, and then the concentration of 20~30%, temperature of 60~66 nitrate (accounted for 1.42) in the cleaning and passivation for half an hour. Concentration of sulfuric acid test solution was 10%, heated to 71 degrees when.302 and 304 stainless steel elbow is immersed in the hot solution, rapid corrosion and a large number of bubbles, sample within a few minutes of black; and 316 and 317 steel bend specimen is not subject to corrosion or reaction is very slow (bubble) sample in 10 to 15 minutes do not change color. At the same time, if the test sample with known composition to approximate comparison, can make the test more accurate.
Copper sulfate test is fast to distinguish between ordinary carbon steel elbow and all types of stainless steel elbow is the most simple method. The use of copper sulfate solution concentration is 5~10%. Before the test, the test area should be thoroughly cleaned of oil or various impurities, and polishing cloth polishing a small region, then dropping to clean up after the regional drop note copper sulfate solution. Ordinary carbon steel elbow or iron elbow in a few seconds will form a layer on the surface of copper, and the surface of the stainless steel elbow does not produce copper precipitation or copper color.

The magnetic test is the easiest way to distinguish the annealing of stainless steel elbow and ferritic stainless steel elbow. Austenitic stainless steel elbow is non-magnetic steel elbow, but the high pressure after cold working with mild magnetic; and pure chrome steel elbow and low alloy steel elbow are strong magnetic steel elbow.

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Stainless steel pipeline installation technology by

General rules for stainless steel pipeline
1 check the quality of each part of the piece, do not meet the requirements should be timely treatment, prevent the unqualified parts for the system.
The use of nylon sling should be 2 stainless steel pipeline lifting, prohibit the use of stainless steel wire rope hoisting stage.
3 connecting the various components, welding elbow, flange, high pressure valve, welding after passing inspection.
The use of 4 pipeline valves, instrumentation, before the installation according to the design requirements of the strength and sealing test, inspection qualified, not qualified to install. Meet the installation requirements should be accompanied by a certificate.
Before the installation of 5 stainless steel pipelines, should be measured according to the drawings, the scene did not confirm the question for installation.
6 stainless steel pipeline installation, should have adjusted, should according to the actual measurement, according to the actual measurement of the size of cutting required size adjustment.
7 stainless steel pipeline installation should check whether the stainless steel pipeline cleaning, if the pipe is dirty, should be timely treatment. In the installation of welding.

8 stainless steel pipeline installation required to fill out the “pipeline construction inspection record”

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