Flanges are the parts that connect the shaft to the shaft and are usedfor the connection between the pipe ends. They are also used for flanges on theequipment inlet and outlet, for the connection between two devices, such as thereducer flange. Flange connection or flange joint refers to the detachableconnection of flanges, gaskets and bolts as a set of combined sealingstructures. Due to its excellent performance, flanges are widely used inchemical, construction, water supply, drainage, petroleum, light and heavyindustry, refrigeration, sanitation, plumbing, fire protection, power,aerospace, shipbuilding and other basic projects.
All of our vacorda measuring instruments need them. In order to make itmore clear about the flanges when the customer use our measuring instruments.Here we give you some brief introduction about the flanges.
1. Basic introduction of flange
Pipe flanges and their gaskets and fasteners are collectively referred toas flange joints.
2.1. Application: Flange joints are a kind of parts that are used widely in engineeringdesign and cover a wide range of aspects. It is an indispensable part of pipingdesign and fitting valves, and it is also an essential component of equipmentand equipment components (such as manholes, sight glass level gauges, etc.). Inaddition, flange joints are often used in other professions such as industrialfurnaces, thermal engineering, water supply and drainage, heating and ventilation,and self-control.
2.2. Material: Forged steel, WCB carbon steel, 316L, 316, 304L, 304, 321, chromiummolybdenum steel, chromium molybdenum vanadium steel, molybdenum titanium,rubber lining, lined with fluorine material.
2.3. Classification: Flat welding flange, with neck flange, butt welding flange, ringconnection flange, socket flange, and blinds.
2.4. Implementation standards: There are GB series (national standards), JB series (mechanicaldepartment), HG series (chemical department), ASME B16.5 (American standard),BS4504 (British standard), DIN (Germany standard), JIS (Japanese standard).
2.5. The international standard flange flangesystem: There are two main systems for internationalstandards for pipe flange:
European pipe flange system represented by German DIN (including theformer Soviet Union)
American pipe flange system represented by American ANSI pipe flange.
2. Types andfeatures of common used flange
1. Plate flat welding flange (Chemical standard HG20592, national standard GB/T9119, mechanicalJB/T81).
Advantages:
Easy to draw, simple to manufacture, low cost, widely used.
Disadvantages:
Due to poor rigidity, it cannot be used in chemical process pipingsystems where there are supply, demand, flammability, explosives, and highvacuum levels, and in highly hazardous locations.
The sealing surface type has flat and protruding surfaces.
2. Slip-onflange with neck
Slip-on flange with neck is a standard system of national standard flange. Itis one of the expressions of national standard flange (also called GB flange)and it is one of the commonly used flanges on equipment or pipelines.
Advantage:
The installation on the spot is more convenient, and the welding seam canbe omitted.
Disadvantages:
The neck-flanged neck has a low neck height, which improves the rigidityand load-bearing capacity of the flange. Compared with butt welding flanges,the welding work load is large, the welding rods are high in consumption, andcannot withstand the high temperature and high pressure and the repeatedbending and temperature fluctuations.
3. Welding flange with neck
The sealing surfaces with neck butt welding flanges are:
Raised face (RF), concave face (FM), convex face (M), facet (T), grooveface (G), full face (FF).
Advantage:
The connection is not easily deformed, has good sealing effect and iswidely used. It is suitable for pipelines with large temperature or pressurefluctuations or high temperature, high pressure and low temperature pipelines,and also for conveying expensive media, inflammable and explosive media, toxic gaspipelines.
Disadvantages:
The flanges with neck butt welded flanges are bulky, heavy, expensive,and difficult to install and position, making it easier to bump in transit.
4. The integral type flange
The integral flange is a flange connection. It is also a kind of flange withneck welded steel pipe. Materials contains carbon steel, stainless steel, alloysteel and so on.
It mostly used in high pressure pipelines, the production process isgenerally casting. Generally, it is a protruding surface (RF). If it is usedunder flammable, explosive, high and extremely hazardous working conditions,the sealing of the convex and concave surfaces (MFM) and the groove surface(TG) other than the RF surface may be selected. The form of the face.
5. Socket welding flange
The socket welding flange is a flange that is bolted to one end and theother end of the steel pipe.
Sealing surface form:
Raised surface (RF), concave-convex surface (MFM), grooved surface (TG),and ring-connected surface (RJ).
Application range:
Boiler pressure vessels, petroleum, chemicals, shipbuilding,pharmaceuticals, metallurgy, machinery, food and other industries.
Commonly used in PN ≤ 10.0MPa, DN ≤ 40 in the pipeline.
6. Threaded flange
Threaded flanges are made by machining the internal bore of a flange intoa pipe thread, and are connected to a threaded pipe to make a connection. Thisis a non-welding flange.
Advantage:
Compared with the flat-welded or welded flanges, the threaded flanges areeasy to install and maintain, and can be used on pipelines that are not allowedto be welded on site. Alloy steel flanges have sufficient strength but are noteasy to weld or have poor welding performance. Threaded flanges are alsoavailable.
Disadvantages:
In the event of a sharp temperature change in the pipeline or atemperature higher than 260°C below -45°C, it is recommended not to use athreaded flange to prevent leakage.
Sichuan Vacorda Instruments Manufacturing Co., Ltd
21 Years Focused onLevelMeasurementinExtremeProcessConditions
Tel: +0086 28 8701 3699
Email: sales@vacorda.com
Web: www.vacorda.com
Post time: 21-09-21