Slip-on flange with neck SO
The hubbed slip-on flange (SO) is a detachable sealing component used in industrial piping systems to connect pipe to pipe, valves, or equipment. Its body has a short conical neck; after the pipe is inserted into the flange bore, it is fixed by fillet welding. This structure effectively disperses pipe stress, reduces the risk of weld cracking, and offers better overall rigidity and fatigue resistance than the plate slip-on flange. The product complies with HG/T20592 (European PN system) and ASME B16.5 (American Class system) standards, and the sealing face can be provided in RF raised face, MFM male and female face, TG tongue and groove face, and other types. Materials cover carbon steel, alloy steel, and stainless steel, and pressure ratings cover PN10 to PN100 as well as Class150 to Class600. The hubbed slip-on flange is suitable for medium-temperature and medium-pressure working conditions, but is not suitable for pipelines with extremely high temperature and high pressure or severe alternating loads. It achieves a good balance between installation convenience and structural strength, and is a commonly used flange type in industrial piping projects. We provide stock in multiple specifications and materials, and support non-standard customization. Welcome to contact us for detailed parameters and quotations.
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Welding Neck Flange WN
Welding neck flange (WN), commonly known as a high-neck flange, is integrally forged and formed, with a long tapered transition neck, and is connected to the pipeline by full-penetration butt welding through the neck bevel, which is different from the fillet weld connection of a slip-on flange. The tapered neck structure can smoothly distribute pipeline stress, has strong resistance to fatigue, bending moments, and alternating temperature changes, and the weld can undergo RT and UT nondestructive testing, with controllable welding quality, making it the preferred flange for high-temperature and high-pressure, flammable and explosive, and toxic medium working conditions. The products implement HG/T20592 (European standard PN system), HG/T20615 (American standard Class system), GB/T9115, ASME B16.5, and ASME B16.47 standards, and the sealing surfaces cover RF, MFM, TG, RTJ, and other forms, among which RTJ is specially used for ultra-high-pressure working conditions. The materials cover carbon steel, alloy steel, stainless steel, and duplex steel, with pressure ratings from PN10 to PN420/Class150 to 2500, and are widely used in pressure piping systems in petroleum, chemical, power, coal chemical, metallurgy, and other industries. We provide full-process customization services, and welcome detailed parameters to obtain accurate quotations.
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Socket Weld Flange SW
The socket weld flange (SW) is a forged small-diameter high-pressure flange. The pipe is inserted into the socket of the flange and then fillet welded on the outside to secure it, and sealing is achieved by bolts and gaskets. The mainstream applicable diameters are DN15-DN80 (NPS 1/2″-3″), and it complies with standards such as ASME B16.5, GB/T9119, and HG/T20592. Compared with threaded flanges, it eliminates the risk of thread leakage; compared with butt weld flanges, it requires no beveling and allows faster installation. The product is widely used in high-pressure small pipelines in chemical, oil and gas, power plant, water treatment, and other industries, and is suitable for high-temperature, high-pressure, and vibrating working conditions. Guojie provides materials such as carbon steel and stainless steel, supports non-standard customization, and welcomes you to provide dimensions and pressure ratings so that we can assist with selection.
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Threaded Flange TH
TH threaded flange, also known as screwed flange, is a forged non-welded flange that relies on the internal tapered pipe thread of the flange and the external threaded steel pipe being screwed together for assembly, and then cooperates with bolts and gaskets to achieve sealed pipeline connection. Mainstream execution standards include ASME B16.5, GB/T9116, HG/T20592, HG/T20615, common diameters are DN15-DN100 (NPS 1/2″-4″), mostly used for small and medium diameter pipelines. Its greatest advantage is that it does not require hot work welding, making it suitable for explosion-proof, welding-prohibited, renovation and emergency repair scenarios, but limited by the threaded structure, it is not suitable for main pipelines with severe thermal cycling and strong vibration. The product is widely used in instrument air supply, gas, fire protection, and utility auxiliary pipelines, and is the preferred flange fitting for flammable and explosive environments and galvanized threaded pipelines, often supplied with NPT and BSPT tapered pipe threads. Guojie provides multiple materials, pressure ratings, and sealing face forms, supports non-standard customization, and welcomes you to contact us to confirm specific requirements.
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Loose flange LJ
Loose flange LJ (designation LJ) adopts a two-piece structure: the stub end is butt-welded and fixed to the pipe, and the movable flange plate is loosely fitted on the outer ring and can rotate 360 degrees, completing the sealed connection by means of bolts and gaskets. This design keeps the flange plate from directly contacting the conveyed medium, so in corrosive pipelines, only the stub end needs to use stainless steel or special alloy, while the flange plate can use carbon steel, which can significantly reduce material costs. At the same time, the flange plate can rotate freely, solving the problem of difficult bolt hole alignment on site, making installation and maintenance more convenient. The product implements standards such as ASME B16.5, GB/T9120-9122, HG/T20592, covering DN15-DN600 (NPS1/2"-24"), with pressure ratings Class150-600LB, PN6-PN40, suitable for low and medium pressure working conditions such as chemical industry, water treatment, food and pharmaceutical, and ship seawater pipelines. Guojie provides full-size stock and customization services, supports mixed-batch procurement, and is backed by comprehensive after-sales service.
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Blind Flange BL
BL blind flanges are manufactured using an integral solid forging process, with no sand holes, blowholes, or laminations, featuring high density, strong pressure-bearing performance, resistance to high pressure and impact, and resistance to deformation and cracking. The full range of sizes is standard, with precise bolt hole positions and high flatness of the sealing face. When paired with gaskets, they can achieve zero-leakage sealing, making them suitable for permanent plugging or repeated disassembly and pressure testing. The products cover mainstream standards such as ASME, GB, HG, and EN, with nominal diameters from DN15 to DN1200, pressure ratings from Class150 to 2500LB or PN6 to PN160, and sealing face forms including RF, FF, MFM, TG, RJ, etc. We keep regular stock, support low minimum order quantities, mixed batches, and non-standard customization, and provide export-grade packaging and after-sales service to meet the procurement needs of B2B customers worldwide.
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Integral Flange IF
Integral flange (IF) is a key component in industrial pipeline connections. Its uniqueness lies in the fact that the flange and the equipment body (such as valves, pumps, pressure vessels, etc.) are manufactured by integral forging or casting, forming an inseparable whole. Therefore, it has no weld seam like traditional welded flanges, has high structural rigidity, and uniform stress distribution, and can withstand high pressure, high temperature, vibration, and alternating loads, making it particularly suitable for harsh media such as flammable and explosive, toxic and harmful substances. This product complies with domestic and international standards such as HG/T20596, GB/T9113, ASME B16.5, EN1092-1, etc. The nominal diameter range is DN15-DN600, the pressure rating is Class150-2500LB or PN16-PN160, and the sealing surface forms are diverse. We provide various materials such as carbon steel and stainless steel, and support non-standard customization to meet the special needs of different projects.
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Reducing flange
A reducing flange is a transitional flanged pipe fitting with a standard flange outer diameter at one end and a different connecting pipe diameter at the other end. It is used to achieve flanged connection between pipes or equipment interfaces of two different nominal diameters, eliminating the step of installing a combination of an ordinary flange and a reducer. Compared with traditional solutions, the reducing flange has a more compact structure, reduces one weld seam, saves installation space, and lowers the risk of leakage. The product complies with standards such as ASME B16.5, GB/T9114, HG/T20592, and HG/T20615, with specifications covering DN15-DN600 and pressure ratings of Class150-2500LB and PN6-PN160. We provide various materials including carbon steel and stainless steel, and support concentric/eccentric types, various sealing faces, and non-standard customization. Reducing flanges are widely used for diameter-changing connections in pipelines in chemical, oil and gas, power plant, water treatment, and other industries, as well as for pump and valve inlet/outlet connections and transitions for non-standard equipment interfaces. Because the processing difficulty is higher than that of standard flanges, stock is relatively limited, and most specifications require customization. You are welcome to provide dimensions and quantities, and we will assist with a quotation.
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Orifice flange
The orifice flange is a core pipe fitting for differential pressure flow measurement. It is used in pairs, with an orifice plate clamped in between. It collects the upstream and downstream pressure differential through pressure tapping holes and works with a differential pressure transmitter to achieve precise measurement of fluid flow. The product complies with ASME B16.36 and HG/T20592 standards, with nominal diameters from DN25 to DN600, pressure ratings from Class300 to 2500LB or PN10 to PN160, and no Class150 low-pressure specification. Compared with ordinary flanges, orifice flanges come with NPT pressure tapping threaded holes and set screws, allowing quick disassembly and assembly of the orifice plate without shutting down the pipeline, which facilitates inspection and maintenance. The product adopts integral forging and CNC precision turning processes to ensure hole coaxiality and sealing performance, and is suitable for trade measurement and process control in industries such as petroleum, chemical, natural gas, and power. We provide flexible customization services, supporting non-standard sizes, special materials, and sealing surface machining to meet the needs of different projects.
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