To introduce the standard of threaded flange, we should first know some common quantities of threaded flange, such as nominal diameter DN, steel pipe outer diameter A, and some connection dimensions, such as flange outer diameter D, bolt hole central circle diameter K, bolt hole diameter L, bolt hole number N, thread Th, flange thickness C, flange neck N, R, flange height H, flange theoretical weight kg, and pipe thread specification Rc, Rp or NPT in inches.
DN is 10mm, then a is 17. 2mm, D is 90mm, K is 60mm, L is 14mm, N is 4, Th is M 12, C is 14mm, N is 30mm, R is 3mm, H is 22mm, and the weight is 0.
64kg, the specification is 3/8 inch; DN is 15mm, then a is 2 1. 3mm, D is 95mm, K is 65mm, L is 14mm, N is 4, Th is M 12, C is 14mm, N is 35mm, R is 3mm, H is 22mm, and the weight is 0.
7 1kg, the specification is 1/2 inch; DN is 20mm, then a is 26. 9mm, d is 105mm, k is 75mm, l is 14mm, n is 4, Th is M 12, c is 16mm, n is 45mm, r is 4mm, h is 26mm, and the weight is/kloc.
02kg, specifications for 3/4 inch; DN is 25mm, so A is 33. 7mm, d is 1 15mm, k is 85mm, l is 14mm, n is 4, Th is M 12, c is 16mm, n is 52mm, r is 4mm and h is 28 mm.
23kg, the specification is 1 inch; DN is 32mm, then a is 42. 4mm, d is 140mm, k is 100mm, l is 18mm, n is 4, Th is M 16, c is 18mm, n is 60mm, r is 5mm and h is 30.
96kg, the specification is 1? 1/4 inch; DN is 40mm, then a is 48. 3mm, d is 150mm, k is 1 10mm, l is 18mm, n is 4, Th is M 16, c is 18mm, n is 70 mm.
3 1kg, the specification is 1? 1/2 inches; DN is 50mm, then a is 60. 3mm, d is 165mm, k is 125mm, l is 18mm, n is 4, Th is M 16, c is 20mm, n is 84mm, r is 5mm, h is 34mm, and the weight is 3.
04kg, size 2 inches; .
2. What is a threaded flange?
This is a comparison in the book. In fact, it is often said that welded pipes are generally connected with threaded products, and the most commonly used one is DN 15-DN 100.
Threaded flange is a kind of flange structure widely used in engineering construction, which has the advantages of convenient on-site installation and no welding. As this revision expands the steel pipe outer diameter series applicable to flanges from metric pipes to metric pipes and British pipes, the varieties of threaded flanges are added according to ISO7005- 1.
Threaded flanges are only applicable to British piping series. When the thread type of the threaded flange is 55 pipe thread specified in GB7306, the outer diameter of the steel pipe for DN 150 flange should be 165.
1 mm. When using 60 taper pipe thread, the outer diameter of steel pipe for DN65 flange should be 73mmDN 125, and the outer diameter of steel pipe for flange should be 14 1.
3 mm. Special attention should be paid to setting the nominal pressure range and nominal diameter range of threaded flanges according to ISO7005- 1.
It's PN0. 6~4。
0MPA, dn10 ~150 mm. there are two kinds of sealing surfaces of threaded flanges: full plane and convex surface.
Considering the structural characteristics of the threaded flange. Therefore, it is not suitable for flammable/explosive and highly dangerous situations.
Low nuclear pressure, such as air conditioning water system, can be used safely. For example, the pipe fittings on tap water for domestic use are threaded.
3. What is the size of the threaded flange?
Threaded flange, as its name implies, is a non-welded flange, that is, the hole in the middle of the flange is processed, the smooth hole is processed into pipe thread, and then this threaded flange is used together with the threaded pipe.
Because it can be disassembled and tightened, it is more convenient to maintain and clean the machine by using this threaded flange. However, in any case, it is not suitable to use the threaded flange, because the temperature in the threaded pipe fluctuates greatly and is greatly affected by the environment, so it is best to use the welded flange in the environment above 20 degrees Celsius or below -40 degrees Celsius.
Of course, different machine installations require different flange sizes. Therefore, in order to unify the standards, the state has determined the standard size of threaded flanges, and facilities with different specifications can use threaded flanges with different sizes.
China's regulations on threaded flanges include specifications, forms and dimensional parameters: the inner diameter is 48 to 408. 6 mm, a wide range, so it also meets the conditions of being widely used.
Generally, the flange outer diameter is about 50-840, the bolt thickness is 14-52, and the bolt hole spacing is 4-36. This is written in the flange specification sheet.
In refrigeration and ventilation equipment, the manufacture of spiral flange is very common, and there will be spiral flange in every refrigeration and ventilation equipment. With a threaded flange, of course, there must be a threaded pipe to match it in order to be perfectly equipped. In order to meet the size of the threaded flange, the threaded pipe also has a variety of corresponding specifications.
These threaded pipes are generally made of the same material as the threaded flanges, so as to achieve the effect of consistent quality and complete equipment. At present, threaded flanges and threaded pipes are basically steel, because steel has stronger compression resistance and better corrosion resistance than other materials.
Because the steel material is hard, it is very convenient in the installation process and not easy to break, which achieves the ideal use effect of threaded flange and is an ideal material for making threaded flange. The use of this threaded flange not only greatly prolongs the service life of equipment and facilities, but also brings endless convenience to maintenance.
4. Flange knowledge
Flanges can be subdivided into flat welding flange (flat welding flange PL, neck welding flange SO), welding flange (neck welding flange) (WN), integral flange (IF), socket welding flange (SW), threaded flange (Th), butt welding ring loose sleeve flange (PJ/SE), flat welding ring loose sleeve flange (PJ/PR) and flange cover (W
The sealing surface forms of flange include RF (ordinary convex seal), M (convex seal), FM (concave seal), MFM (concave seal), T (tenon seal), TG (tenon seal) and RJ (stepped groove seal, FF (full plane seal).
The flange standards are: European standards HG20592, HG20593 \ HG20594 \ HG20595 \ HG20596 \ HG20597 \ HG20598 \ HG20599 \ HG20600 \ HG20601\ HG20602.
The American system is: Hg 20616 \ Hg 20617 \ Hg 20615 \ Hg 20618 \ Hg 20619 \ Hg 2062/kloc-0.
5. Pipe thread knowledge
I didn't know there was such a website.
But for books about pipes, there is a chapter about this in the mechanical design manual.
If you don't have a book, you can download an electronic mechanical design manual.
For these accessories of pipeline, the thread is pipe thread, which is different from the common thread ratio, that is, the tooth angle. The common thread is 60, and the included angle of pipe thread is 55. However, for pipeline, it is generally unnecessary to express it, and its size is generally expressed in inches.
By the way, please send me an email. I have a PDF file in my computer.
The professional knowledge about pipelines is very comprehensive. After reading it, you must be an expert in pipelines.
Haha,
6. Knowledge about flanges
Flanges are also called flanges or flanges. It is used for the connection between pipes, including threaded flanges and welded flanges, and is generally used for the connection between water pipes and gas pipes.
Flanges are divided into threaded (threaded) flanges and welded flanges. Threaded connection flanges are used for small diameter low pressure, and welded flanges are used for large diameter high pressure and low pressure. Under different pressures, the thickness of flange and the diameter and number of connecting bolts are different. According to different pressure grades, flange pads are made of different materials, ranging from low-pressure asbestos pads, high-pressure asbestos pads to metal pads. Flange connection is easy to use and can withstand greater pressure. Flange connection is widely used in industrial pipelines. At home, the pipe diameter is small and the pressure is low, so the flange connection is invisible. If you are in the boiler room or production site, there are flanged pipes and equipment everywhere. There are holes in the flanges through which bolts can pass, so that the two flanges are closely connected. The flange is sealed with a gasket. Flanged pipe fittings refer to pipe fittings with flanges (flanges or flanges). It can be formed by casting, threaded connection or welding. Flange, joint) consists of a pair of flanges, a gasket and several bolts and nuts. The gasket is placed between the sealing surfaces of two flanges. After the nut is tightened, the specific pressure on the gasket surface will be deformed after reaching a certain value, and the uneven part on the sealing surface will be filled to make the connection tight. Flange connection is a detachable connection. According to the connection parts, it can be divided into container flange and pipeline flange. According to the structure type, there are integral flange, loose sleeve flange and threaded flange. Common integral flanges are flat welded flanges and welded flanges. Flat welding flange has poor rigidity, which is suitable for situations where the pressure p is less than or equal to 4 MPa. Welding flange, also known as high neck flange, has high rigidity and is suitable for occasions with high pressure and temperature. There are three kinds of flange sealing surfaces: plane sealing surface, which is suitable for occasions with low pressure and non-toxic medium; Concave-convex sealing surface, suitable for occasions with slightly higher pressure; The tenon-groove sealing surface is suitable for flammable, explosive and toxic media and high-pressure occasions. The gasket is a circular ring made of plastic deformation and certain strength. Most gaskets are cut from nonmetallic plates or made by professional factories according to the specified size, and their materials are asbestos rubber plates, asbestos plates, polyethylene plates and so on. There are also metal-clad gaskets made of non-metallic materials such as asbestos wrapped with thin metal plates (iron sheets and stainless steel); There is also a kind of wound gasket, which is made of thin steel strip and asbestos strip. Ordinary rubber gasket is suitable for occasions where the temperature is lower than 120℃; Asbestos rubber gasket is suitable for occasions with steam temperature below 450℃, oil temperature below 350℃ and pressure below 5MPa. For general corrosive media, the most commonly used is acid-resistant asbestos board. Lens-shaped or other metal gaskets made of copper, aluminum, 10 steel and stainless steel are used in high-voltage equipment and pipelines. The contact width between high-pressure gasket and sealing surface is very narrow (line contact), and the machining smoothness between sealing surface and gasket is high.