Pipe Cap
A pipe cap is a core pipe fitting used in pipeline engineering to close the end of a pipeline. Unlike a detachable flange cover, it is a permanent sealing solution, offering stronger sealing performance and better pipeline integrity after welding. We use integrated stamping and forging forming processes, resulting in a dense product structure and uniform pressure bearing, capable of withstanding high pressure, high temperature, and corrosive environments. Pipe caps are mainly used to seal idle pipe openings, reserved ports, and equipment terminals, preventing medium leakage while also blocking external impurities from entering the pipeline. We support full-specification stock and non-standard customization, covering various materials such as carbon steel, stainless steel, and duplex steel, and can produce according to standards such as national standards and American standards. Whether you are engaged in foreign trade bulk procurement, engineering project centralized procurement, or equipment repair and replacement, we can provide corresponding products and export documentation support.
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Oval Tube Cap
Elliptical pipe caps adopt the industry-standard 2:1 major-to-minor axis standard elliptical ratio, are composed of a curved surface and regular straight edge sections, and are integrally stamped and formed as a whole without spliced welds. Compared with dished, flat-bottomed, or spherical-crown pipe caps, the elliptical curved surface can more evenly distribute the internal fluid pressure, steam pressure, and medium impact forces within the pipeline, reducing the risk of deformation and leakage caused by stress concentration at the ends. The elliptical pipe caps we produce comply with GB/T12459, GB/T25198, and ASME B16.9 standards, with nominal diameters covering DN15 to DN4000, wall thicknesses from 2 mm to 100 mm, and pressure ratings from PN10 to PN100. Material, surface treatment, and packaging method can be confirmed according to project requirements. You are welcome to contact us with dimensions, quantity, and standard requirements so that we can assist with a quotation.
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Hemispherical (spherical) pipe cap
A hemispherical pipe cap is also called a spherical pipe cap, hemispherical head, or hemispherical end cap, and belongs to the major category of convex pipe caps/heads, known in English as Hemispherical pipe cap / Hemispherical head. It is composed of a standard hemispherical shell plus a straight edge section (welding groove), with a cross-section that is a standard semicircle, and the spherical surface radius of curvature equal to the cylinder inner diameter. Among all convex pipe caps, the hemispherical pipe cap has the optimal stress conditions, the most uniform stress distribution, the smallest required wall thickness under the same working pressure, and the strongest pressure-bearing performance, making it suitable for high-pressure and ultra-high-pressure working conditions. The product uses welded connection and belongs to permanent sealing accessories, different from removable blind plates. We provide carbon steel, stainless steel, heat-resistant alloy steel, duplex steel, titanium alloy, and many other materials, and support customization of non-standard sizes, special wall thicknesses, special groove forms, and surface treatments, and can assist with selection according to customer drawings or working condition parameters.
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Dish-shaped (butterfly-shaped) pipe cap
The curved surface radian of the dished head is flatter than that of the elliptical head, making it suitable for pipe end sealing under low-pressure and normal-temperature working conditions, with higher cost-effectiveness. The dished heads we produce comply with GB/T12459, ASME B16.9, and DIN2617 standards, with materials covering carbon steel, stainless steel, and alloy steel, nominal diameters from DN15 to DN2000, wall thicknesses from 2.5mm to 60mm, and pressure ratings from PN10 to PN64 and Class150 to Class900. The products are formed by integrated spinning or stamping, with no spliced welds, and are used to seal idle pipe ports, reserved interfaces, and equipment terminal pipe openings, preventing impurities and moisture from entering the interior of the pipes. The MOQ for regular in-stock models is 1 piece, and sample purchases and small-quantity replenishment are supported.
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Spherical cap
Spherical crown-shaped pipe caps are one of the four mainstream convex pipe caps in industry, alongside hemispherical, elliptical, and dished heads. Their structure consists of a spherical crown body and a straight edge section, with no flanged transition, a rounded appearance, and regular surface curvature. The manufacturing process is simpler than that of dished and elliptical heads, with a shorter production cycle and lower cost. The spherical crown-shaped pipe caps we produce are formed by integral spinning or integral forging, with no spliced welds, uniform pressure bearing, and stable stress distribution. Materials cover carbon steel, stainless steel, alloy steel, and special alloys, and they can be supplied according to standards such as GB/T12459, ASME B16.9, and DIN2618. Their pressure-bearing capacity is weaker than that of hemispherical and elliptical heads, but clearly stronger than that of ordinary flat cover pipe caps. They are mainly aimed at medium- and low-pressure general working conditions, used for permanent sealing of pipe ends, closure of reserved pipe openings, sealing of equipment ends, and end head components for auxiliary pressure vessels such as storage tanks, heat exchangers, and buffer tanks.
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Flat Cap
The flat-bottom pipe cap is a basic pipe fitting product we offer for low-pressure pipeline plugging needs. Unlike spherical, butterfly, and elliptical curved heads, its end face is a flat planar structure with no curved arc or folded edge, featuring a simple structure, low cost, and easy installation. The product is formed by integral stamping or forging from a single steel plate, with a flat surface, strong rigidity, and resistance to deformation, high welding fit, and stable plugging and sealing performance. The flat-bottom pipe caps we produce comply with the general pipe fitting standards GB/T12459 and ASME B16.9, with nominal diameters covering DN15 to DN2000, wall thicknesses from 3mm to 80mm, and materials covering carbon steel, stainless steel, and alloy steel, supporting production of conventional standard sizes and thickened non-standard sizes. Its pressure-bearing characteristics are suitable for atmospheric pressure, PN10, PN16, and PN25 low-pressure working conditions, and it is not suitable for medium- and high-pressure demanding equipment scenarios. Its main uses are permanent sealing of pipeline ends, plugging of idle pipe openings, sealing of reserved interfaces, and finishing of pipeline modifications, suitable for harmless media working conditions such as water, gas, oil, and ordinary fluids.
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Tapered tube cap
Conical pipe caps differ from conventional heads such as flat-bottom, spherical crown, dished, and elliptical heads; their core lies in the flow-guiding, buffering, and reducing and closing capabilities brought by the conical gradual transition structure. The conical pipe caps we produce comply with GB/T12459, ASME B16.9, and non-standard pressure vessel head manufacturing standards, and are formed by integral CNC spinning or one-piece forging and pressing, with no segmented splicing welds, uniform cone curvature, and precise taper. The products cover materials such as carbon steel, stainless steel, alloy steel, and duplex steel, and can adapt to high and low temperature, medium and low pressure, and slight wear and corrosion working conditions. They mainly solve the problems of dust accumulation, material accumulation, and siltation and blockage in dead corners of pipeline and equipment sealing, and are used in scenarios such as environmental protection dust removal, desulfurization and denitrification, powder storage, chemical non-standard equipment, reducing pipelines, grain machinery, and metallurgical equipment. Specifications and materials can be customized according to drawings or samples; you are welcome to contact us to confirm the specific configuration.
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BW Butt Weld Pipe Cap
BW butt-welded pipe caps are butt-welded to the pipeline through the port bevel, forming a permanent sealing structure after welding, and are used for closing pipeline ends, plugging reserved pipe openings, and sealing equipment ends. Compared with threaded or socket-welded pipe caps, it has stronger pressure and temperature resistance, and is more suitable for medium- and high-pressure, high-temperature, and long-term operating industrial pipelines. We use integral spinning or forging forming, one-piece molding without splicing welds, regular bevel processing, and after welding, the weld is continuous and the seal is reliable. Materials cover carbon steel, stainless steel, alloy steel, duplex steel, etc., nominal diameter DN15–DN2000, wall thickness 2.5mm–60mm, supporting conventional wall thickness and high-pressure thickened customization. Products are produced according to GB/T12459, ASME B16.9 and other standards, and can be used in oil and gas, chemical, power, heating, sewage treatment, and new energy process pipelines. For specific diameter, material, pressure rating, and surface treatment requirements, please contact us for confirmation before quotation.
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SW Socket Weld Pipe Cap
Guojie SW socket weld pipe caps are integrally die-forged high-pressure pipe fittings, specifically used for end sealing of small-diameter high-pressure piping systems. The pipe end is inserted into the socket of the pipe cap, and then circumferential welding is performed to form a permanent seal, isolating high-pressure gas, liquid, steam, and corrosive media from leaking out, while also blocking dust, impurities, and water vapor from entering the interior of precision pipelines. The product strictly implements the ASME B16.11 and GB/T14383 forged pipe fitting standards, and is formed by hot die forging in one piece, with a dense internal structure, free of defects such as sand holes, porosity, and looseness, and with strong pressure-bearing capacity. Specifications are mainly small diameters from DN6 to DN100, pressure ratings include 3000LB, 6000LB, and 9000LB American standard pound classes, and materials cover carbon steel, stainless steel, alloy steel, duplex steel, etc. The socket weld structure is compact, occupies little installation space, has small welding deformation, and provides stable sealing, making it suitable for working conditions with dense pipelines and limited assembly space. It is mostly used for closing instrument branch pipes, reserved pipe openings, and test pipelines, and is a forged pipe fitting matched for high-pressure process pipelines.
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