Types of flanges
As already described before, the most used flange types ASME B16.5 are: Welding Neck, Slip On, Socket Weld, Lap Joint, Threaded and Blind flange.
First, the different diameter flange
Technical parameters: implemented in accordance with national standards
Quality standards: manufacturing in strict accordance with relevant standards established by the state
Product specifications: DN15-DN2000
Product packaging: wooden box or other
Product color: metallic color
Features: anti-corrosion, acid and alkali resistance, long service life, reasonable price calculation, smooth surface, acid and alkali resistance, high temperature, beautiful appearance, strong texture
Production process: professional overall forging, forging manufacturing, medium plate cutting, medium plate rolling, etc.
Processing methods: high-precision CNC lathe turning, general lathe finishing, argon arc welding, etc.
Nominal pressure sch5s, sch10s, sch20s, sch30s, sch40s, etc.
Manufacturing standards: national standard, American standard, Russian standard, Japanese standard, etc.
Material: 201,304.316.316L.0Cr18Ni9.321.202, etc.
Uses: Widely used in water conservancy, electric power, power stations, pipe fittings, industrial, pressure vessels, etc.
Connection method: flange nut, bolt connection.
Name: Stainless steel flange
Specifications: 1/2" ~ 240" (10-6000)
Pressure rating: 0.6Mpa ~ 32Mpa, 150Lb ~ 2500Lb, PN0.25-PN42.0
Material: 304, 304L, 321, 316, 316L, 310S and other materials
Ministry of Chemical Industry Standards: HG5010-52~HG5028-58, HGJ44-91~HGJ65-91, HG20592-2009 (PN Series), HG20615-2009 (Calss Series)
Applications: Boiler and pressure vessels, petroleum, chemical, shipbuilding, pharmaceutical, metallurgy, machinery, food and other industries.
Third, the pressure vessel flange
Product Name: Pressure Vessel Flange
Product Remarks: Pressure Vessel Flange Application Industry: HVAC Power Building Water Supply Pressure Vessel Accessories, Pressure Pipe Fittings.
Product category: Flange series
Application industry: HVAC Power Building water supply Pressure vessel fittings, pressure piping fittings.
Application technical parameters:
Seal Nominal pressure PN, MPa(bar) 0.6 1.0 1.6 2.5 4.0 6.4
Concave surface (MFM) DN1300~3000 DN300~3000 DN400~2000 DN300~800
(TG) DN1300~3000 DN300~3000 DN300~3000 DN300~800
Full plane (FF) DN300~3000 DN300~3000 DN300~3000 DN300~800
Flat welding flanges include plate flat welded flanges and neck flat welded flanges.
(1) Plate type flat welding flange (PL)
Plate type flat welding flange structure diagram Flat welding flange is suitable for steel pipe connection with nominal pressure not exceeding 2.5MPa. The sealing surface of flat welding flange can be made into smooth, concave and convex and grooved type. Smooth type flat welding The flange is the largest application. It is mostly used in the case of moderate media conditions, such as low pressure non-purified compressed air and low pressure circulating water.
(2) Sketch with neck flat welding flange with neck flat welding flange (SO)
The neck flat welded flange has a low neck height and improves the rigidity and load carrying capacity of the flange. Compared with the butt welding flange, the welding work is large, the welding rod consumption is high, and the high temperature and high pressure, repeated bending and temperature fluctuation cannot be withstood, but the on-site installation is convenient, and the process of welding seam bruises can be omitted, which is more popular.
Five, welding Neck Flanges (WN)
Welding Neck Flanges: Neck flange welds are often referred to as "high-hull" flanges. The purpose is to transfer the pressure of the pipe, thereby reducing the high stress concentration in the flange base. Neck flange welding is the best design for brazing those flanges that provide structural value due to their existence. However, the price is relatively high because the production process of the product is complicated.
The threaded flange is connected by a thread. However, the center of the product has a thread size corresponding to the tube. The main advantage is that it can be assembled without welding.
Seven, Sliding flange
The sliding flange has a lower hinge because the pipe enters the single flange before welding. This is the internal and external weld that provides sufficient strength to prevent leakage. The sliding flanges are all matching of the boring slightly larger outer diameter pipe. They are superior to neck flanges because of the low initial cost and many users, but the final installation cost is probably not as low as the increased weld neck flange is less.
The lap flange is actually the same sliding flange unless it has a radius between the hole and the flange race. It is necessary that the radius has a flange to accommodate the end of the lap stub. Typically, the lap flange and the lap joint will be mated together at the end of the month.
The socket weld flange is a similar sliding flange unless it has a hole and reverse hole size. The counter hole is matched to the pipe so that the pipe is inserted into a similar sliding flange of the flange. The diameter of the smaller holes is the same as the matching of the same ID pipe. The limit is a built-in hole that acts as a sleeve for the pipe to stay at the bottom. This eliminates any flow restrictions on the use of socket weld flanges.
Socket weld flange sealing surface form: raised surface (RF), concave and convex surface (MFM), grooved surface (TG), ring joint surface (RJ)
Material: Carbon Steel: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65 , F70;
Alloy Steel: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/III, 35CrMoV, 45CrMo, etc.
Manufacturing standards: ANSI B16.5, GB/T9117.1-2000-GB/T9117.4-200, etc.
Ten, threaded flange (TH)
Threaded flange nominal diameter: DN8 ~ DN100 Working pressure: 1.0 ~ 2.5 (MPa) Plate thread flange material: stainless steel, carbon steel, alloy steel.
Thread flange use: Suitable for fire-fighting, gas, hot and cold water, air conditioning, air pressure pipe, oil pipe, instrument, hydraulic pipe and other industrial and civil pipe thread lock and seal.
Eleven, flange cover (BL)
The flange cover, also known as the blind flange, is a flange without a hole in the middle for sealing the pipe plug. There are many types of sealing surfaces, such as planes, convex surfaces, concave and convex surfaces, grooved surfaces, and ring joint surfaces.
Sealing surface: plane (FF), protruding surface (RF), concave and convex surface (MFM), grooved surface (TG), ring joint surface (RJ)
Carbon Steel: ASTM A105, 20#, Q235, 16Mn, ASTM A350 LF1, LF2 CL1/CL2, LF3 CL1/CL2, ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70 ;
Stainless Steel: ASTM A182 F304, 304L, F316, 316L, 1Cr18Ni9Ti, 0Cr18Ni9Ti, 321, 18-8;
Alloy Steel: ASTM A182 F1, F5a, F9, F11, F12, F22, F91, A182F12, A182F11, 16MnR, Cr5Mo, 12Cr1MoV, 15CrMo, 12Cr2Mo1, A335P22, St45.8/III.
(1) with neck butt weld ring loose flange
Loose flanges, butt welds, loose sleeves, neck flanges, butt welds, loose sleeves, flat flanges, welded rings, loose sleeves, flanged plates, overturned loose flanges. In addition, in order to meet the needs of the rear locking of the device, there are rods. Holes, these holes can make the bolts not loose when they are vibrated. Some flange bolts have no threaded rods to be thin, called thin rod flange bolts. This kind of flange bolts are beneficial for the coupling of variable forces. There are special high-strength bolts on the structure. The head will be larger. The size is also changed. The hot-dip galvanized round steel reacts the molten metal with the iron matrix to produce an alloy layer.
(2) Flat welding ring loose flange (PJ/SE)
The flat welding ring loose flange is a movable flange. It is usually matched on the water supply and drainage fittings (the most common on the expansion joint). When the factory leaves the factory, there is a flange at each end of the expansion joint, directly in the project. The pipes and equipment are bolted. The purpose of using a flat welding ring to loosen the flange is generally to save material. The structure is divided into two parts. One end of the pipe is connected to the pipe, one end is made into a flange, and the flange is partially placed on the flange. The flanges are made of low-grade materials, and the tubes are made of the same material as the pipes to save material.
(3) Flat welding ring loose flange:
1. Cost savings. When the material of the pipe is special and expensive, the flange of the same material is costly.
2. It is not convenient to weld or inconvenient to process or requires high strength. Such as plastic pipes, glass steel pipes and the like.
3. Easy to construct. If the flange bolt hole is connected during the connection, it is not easy to find or prevent the flange bolt hole of the equipment to be replaced in the future.
Disadvantages of the flat welding ring loose flange:
- 1. Understand low pressure.
- 2. The strength of the weld ring is low (especially when the thickness is less than 3mm)
Flat welding ring loose flange production standards:
National standard: GB/T9112-2000 (GB9113•1-2000~GB9123?4-2000)
American Standard: ANSI B16.5 Class150, 300, 600, 900, 1500 (WN, SO, BL, TH, LJ, SW)
Japanese standard: JIS 5K, 10K, 16K, 20K (PL, SO, BL, WN, TH, SW)
German standard: DIN2573, 2572, 2631, 2576, 2632, 2633, 2543, 2634, 2545 (PL, SO, WN, BL, TH)
Ministry of Chemical Industry Standards: HG5010-52~HG5028-58, HGJ44-91~HGJ65-91
Flange standard: HG20592-2009 (PN series)\HG20615-2009 (Calss series)
Ministry of Machinery Standard: JB81-59~JB86-59, JB/T74-1994, JB/T79-94~JB/T86-94
Pressure vessel standard: NB/T47020-2012~NB/T47027-2012, JB1157-82~JB1160-82 B16.47A/B B16.39 B16.48
(4) Ring groove flange and flange cover
- Large diameter flat flange
- Large diameter high neck flange
- Eight-word blind board
- Butt ring loose flange
Thirteen, rotating flange
- Anchor flange
- Surfacing/welding flange
Marine lap welded steel flange standard number: This standard applies to marine products and marine engineering products. The main materials are: carbon steel, alloy steel, low temperature steel, stainless steel.
Fourteen, forged flange
Forging flange connection is to put two pipes, pipe fittings or equipment, and forging flange connection is an important connection method for pipeline construction. The forged flange connection is easy to use and can withstand large pressures. In industrial pipes, forged flange connections are widely used. In the home, the pipe diameter is small and low pressure, and the connection of the flange punching elbow is not visible. If you are in a boiler room or production site, there are flanged pipes and equipment everywhere. Chromium content 0.1% to 0.5% (forged flanges generally do not contain chromium), carbon content below 1.0% and forged flanges are made of high temperature forging, some forged flange surface hardness (HRC) although It can reach ≥56 or above (the quenching layer is only about 15mm). Because of the poor hardenability of the forged flange material, the hardness of the core is generally only 30 degrees. Under normal circumstances, the water is quenched when forging the flange.
Fifteen, flange protection cover (flange protection joint)
Flange protection covers are mainly used for flange connection corrosion protection in all industries.
Flange Cover The flange protection head of this product is used to protect the flange face (convex or ring joint). Double-ended studs and gaskets are protected from corrosion. The product is available in 316 ss stainless steel and non-metal (plastic) and is manufactured in sizes from ½" to 144" ANSI, API and AWWA flanged diameters. The flange head system in combination with flange packing protects against harsh applications.
The structure of the flange seal:
- 316 stainless steel belt or non-metallic belt
- 316 ss casting
- 316 ss worm gear clamp
- Closed tank neoprene layer (temperature. – 34.4°C to 82°C)
- ECH rubber gasket (temperature. – 34.4°C to 149°C) safety relief valve releases 5 psi
- Advantages of Mestec flange seals:
- Easy to install
- No special tools required
- Easy to detect
- Durable connection (not easily damaged)
- UV stabilized non-metallic materials
Sixteen. Flange packing system
Suitable for temperatures of 80 ° C.
Flange packing is a unique solution to long-term corrosion problems.
The flange filler is a coating based on a composite polar polymer. The paste form allows it to be used without pretreatment. The viscoelastic formulation allows this material to flow into the gaps and voids, creating an excellent seal that is corrosion resistant.
Flange packing system flange packing saves time and money because it is easy to use. Provide long-term protection.
Performance: Excellent adhesion to steel, FBE (fused epoxy powder), polyurethane, polyethylene advanced resistance weathering / salt resistance temperature range from -51 ° C to 80 ° C filling the entire gap removable / reusable flange surface Manual or pneumatic guns with flexible nozzles are used for gentle injection without excessive pre-treatment. This ensures that the annular gap is completely filled before sealing with the CZ wrap tape.
- E-2400/E2000 high temperature flange packing - suitable for temperatures up to 149 °C.
- E-2400/E2000 high temperature anti-corrosion flange filler is designed to protect flanges from corrosion at temperatures up to 149 °C.
- E-2400/E2000 is a non-electrolytic corrosion protection of steel flanges, bolts, pipes and structures with a gel.
The nut and bolt assembly was tested for 2000 hours using the ASTM-B1117 salt spray test. The area protected by the E2000/2400 can still be rotated by hand. Proper use of the E2000/2400 helps protect flange connections from corrosion.
Seventeen, high temperature flange seal
Parts of high-temperature flanges often require a flat high-temperature seal. If there is no good sealant in the separate pressure zone, it will be affected by the pressure, which will cause production inaccuracy or deformation, that is, pressure in the separate pressure zone. Leakage occurs underneath, requiring an unscheduled repair. The best application in the field of high temperature flat seals is the Bocos high temperature sealant, which is specially formulated to remain inert in standard applications for steam and gas turbines and high temperature flanges, thus withstanding hot air, steam, water, light fuel Oil and lubricants are resistant to crude oil and natural gas. It is a one-component, paste-like sealant for industrial applications and high-quality sealing compounds. It is suitable for applications where the temperature and pressure of smooth, flat sealing surfaces (butt joints) are high. Spread on a dry surface using a plaster trowel or a rubber spatula. Since the sealed product will not cure, its consistency will change slightly, maintaining flexibility and flexibility, so there is no time requirement in use, and it can be put into operation immediately after construction, without waiting.