Spherical cap

Overview

Spherical cap heads, also called spherical segment heads, spherical pipe caps, or knuckle-free spherical heads, are convex head pipe fittings used for pipe sealing and pressure vessel end closure. Their structure consists of a spherical crown body and a straight edge section, with no knuckle transition, a rounded appearance, and regular curved surface curvature. Compared with dished heads and elliptical heads, spherical cap heads have a simpler manufacturing process, shorter production cycle, and lower cost. We use integral spinning or integral forging processes for forming, with no spliced welds, uniform pressure bearing, and stable stress distribution. Products are manufactured according to standards such as GB/T12459, ASME B16.9, DIN2618, etc., with materials covering carbon steel, stainless steel, alloy steel, and special alloys, mainly for medium- and low-pressure general working conditions.

Key Features

The biggest features of spherical cap heads are simplified structure, material savings, and outstanding cost-effectiveness. The knuckle-free transition structure makes them more material-saving than dished and elliptical heads at the same diameter, with lower procurement cost. Integral spinning or integral forging forms them in one piece, with no spliced welds and no stress concentration problems caused by welds, and their sealing performance and stability are clearly better than ordinary flat cover heads. The curved surface transitions evenly, and pressure-bearing performance is stable. Raw materials use genuine plates from major mills, with pure material, uniform wall thickness, sufficient toughness, corrosion resistance, aging resistance, and resistance to deformation. Although pressure-bearing capacity is weaker than hemispherical and elliptical heads, it far exceeds ordinary flat cover pipe caps, making it suitable for medium- and low-pressure pipeline sealing and equipment end closure.

Applications

Spherical cap heads are mainly aimed at medium- and low-pressure industrial pipeline and equipment scenarios. In industrial production, they can be used for process pipeline sealing and equipment terminal closure in petrochemicals, coal chemicals, natural gas transportation, power stations, metallurgical manufacturing, and new energy plants. In municipal engineering, they cover end sealing, project completion, and pipeline renovation construction for urban water supply and drainage networks, heating networks, gas pipelines, and rainwater and sewage pipe networks. In special equipment, they are suitable for head assembly of buffer tanks, water storage tanks, oil storage tanks, heat exchangers, filtration equipment, and pressure stabilizing vessels. In addition, they can also be used in scenarios such as ship auxiliary pipelines, low-pressure pipelines on offshore platforms, pharmaceutical clean pipelines, and food processing conveying pipelines. Products can be used long-term in outdoor open-air, buried humid, and indoor enclosed environments.

Specifications

Spherical cap heads are produced according to standards such as GB/T12459, ASME B16.9, DIN2618, etc., and are formed by integral spinning or integral forging processes, with no spliced welds. Materials can be selected from carbon steel, stainless steel, alloy steel, and special alloys, and the specific grades can be confirmed according to project working conditions. We support customization of DN15–DN2000 non-standard diameters, special thickened wall thickness, special spherical cap height, and irregular curved surface curvature, and can also adjust pressure rating, straight edge length, and groove angle as needed. For regular stock standard models, sorting, quality inspection, packing, and outbound shipment are completed within 24–48 hours after payment confirmation. Please contact us to confirm specific specifications, materials, and delivery time.

Purchase & Delivery

We have set flexible minimum order quantity standards for spherical cap heads. For regular stock standard sizes, regular pressure, and regular material models, the MOQ is as low as 1 piece, supporting sample testing, small engineering replenishment, and small-order trial sales. Bulk centralized procurement and foreign trade distribution orders can be confirmed separately according to project needs. For regular national standard and American standard stock standard models, outbound shipment can be completed within 24–48 hours after payment confirmation. For the delivery time of regular standard batches within 1000 pieces, as well as the production cycle of non-standard customized orders, please contact us to confirm. Packaging adopts a standardized foreign trade export-grade solution: small-diameter pipe caps are wrapped in waterproof PE film and filled with shock-absorbing buffer foam; medium- and large-diameter heads are wrapped on the outer layer with thickened waterproof and rainproof cloth, and pipe openings are equipped with dust plugs and anti-collision protective rings; the entire batch of goods is fixed on solid wood pallets or fumigation-free export wooden frames, reinforced with high-strength strapping, and sealed with multiple layers of stretch film wrapping. Foreign trade shipping marks, LOGO identification, specification labels, and quantity markings can be customized according to requirements.

Service & Support

We provide pre-sales and after-sales support for customers purchasing spherical cap heads. Before sales, we can provide working condition analysis, model selection, parameter matching, and solution optimization to help confirm the suitable material, diameter, and pressure rating and avoid selection errors. After sales, we provide installation guidance, welding process recommendations, and technical Q&A. After order shipment, we provide full-process logistics tracking and assist overseas customers with customs clearance and receiving. The product warranty period is 18 months, and during the warranty period, quality problems caused by non-human damage are eligible for free repair and replenishment. If there are factory quality problems, dimensional deviations, material mismatch, or process defects, free returns, exchanges, and reshipment are supported, and logistics losses are borne by us. Dedicated after-sales specialists respond online 7×24 hours to handle orders, quality, logistics, and after-sales issues.