The controlled flanged stub end is machined from a single seamless steel pipe, with no spliced welds, and is formed through processes such as facing, beveling, integral flanging, shaping, and polishing. The products are divided into two structures: long pattern LP and short pattern SP, complying with ASME B16.9, MSS SP43, and GB/T12459 standards, and are compatible with global lap joint flange assembly systems. Compared with stamped flanged stub ends, the controlled version has more advantages in end face flatness, sealing stability, and pressure uniformity, making it suitable for DN15–DN600 small and medium diameter pipelines. We can provide standard stock specifications such as carbon steel and 304/316 stainless steel, and also support customization of non-standard diameters, thickened flanges, and special materials. Welcome to contact us to confirm the specific working condition selection and configuration.
Product Overview
The pipe-type lap joint stub end is a pipeline connector made from seamless steel pipe as raw material and integrally formed through CNC precision turning. It does not use steel plate stamping or plate rolling and welding, but is processed through multiple procedures such as plain end, beveling, integral flanging, shaping, and polishing. One end of the product is a standard butt-weld bevel, which can be seamlessly butt-welded to the pipeline; the other end is a precision-turned lap joint sealing surface, which works with a loose flange to achieve 360° free rotational alignment. This structure is especially suitable for scenarios such as misaligned bolt holes at the construction site, fixed equipment nozzles that cannot rotate, and difficult installation in narrow spaces. The product is divided into two structures: long type LP and short type SP, follows ASME B16.9, MSS SP43, and GB/T12459 standards, and is compatible with the global loose flange assembly system.
Key Features
The core advantage of the pipe-type lap joint stub end lies in seamless integral forming. The entire seamless steel pipe is CNC precision machined, with no splicing, no welding, no sand holes or blowholes, and no lamination defects; the pipe material has a dense structure and uniform structural strength. The flanged end face is precision turned and polished, with high flatness and low roughness, fits tightly with the gasket, and does not loosen, leak, or develop indentations during long-term operation. Compared with stamped lap joint stub ends, the pipe-type version has more advantages in precision, sealing performance, and pressure resistance stability; compared with plate-made lap joint stub ends, the pipe-type version is more suitable for DN15–DN600 small and medium diameter standard working conditions. In addition, the combination scheme of using corrosion-resistant pipe-type stub ends with carbon steel loose flanges can reduce the overall project cost while ensuring pipeline corrosion resistance, sealing, and pressure resistance performance.
Applications
Pipe-type lap joint stub ends are mainly intended for pipeline systems with small and medium diameters, high-precision sealing, no impurity precipitation, and conventional temperature and pressure working conditions. In the field of electromechanical equipment, they are used for heat exchanger connections, pressure vessel external connection pipelines, fluid equipment inlet and outlet water pipes, instrument sampling small pipes, etc. In the field of environmental protection and water treatment, they are used for pure water systems, reclaimed water reuse, and auxiliary sewage conveyance pipelines. In the chemical and light industry fields, they are suitable for normal-temperature low-pressure process branch pipes, chemical agent conveyance pipelines, and anti-corrosion auxiliary pipe networks. In the pharmaceutical and food clean fields, the integral pipe material has no lamination, no welding slag, and no pollution precipitation, making it suitable for clean fluid pipelines. In municipal engineering, they can be used for community pipe networks, park conveyance pipelines, and municipal renovation branch pipes. They are also suitable for boiler instrument pipelines, HVAC power pipe networks, and small and medium diameter pipeline systems requiring frequent inspection, disassembly, and reassembly.
Specifications
Pipe-type lap joint stub ends are divided into two structures: long type LP and short type SP. The long type is suitable for medium- and high-pressure process pipelines, and the short type is suitable for low-pressure conventional pipe networks. They implement ASME B16.9, MSS SP43, and GB/T12459 standards. The applicable diameter range covers DN15–DN600. Carbon steel, 304 stainless steel, and 316 stainless steel are kept in regular stock, and special corrosion-resistant and high-temperature-resistant pipe materials such as 2205 duplex steel, 15CrMo alloy steel, and copper-nickel alloy can be customized. Customization is supported for non-standard diameters, non-standard straight pipe lengths, widened and thickened flanged sealing surfaces, and extra-thick pressure-bearing wall thicknesses. In terms of processing, mirror-finish precision-turned sealing surfaces, ultra-high-precision zero-tolerance precision machining, and internal and external polishing treatments can be provided. For specific parameters such as wall thickness grade, pressure grade, and material matching, please contact us for confirmation.
Procurement & Delivery
We set a low-threshold, flexible tiered minimum order quantity for pipe-type lap joint stub ends. For DN15–DN300 mainstream conventional diameters, STD/SCH40 standard wall thicknesses, and carbon steel and 304/316 stainless steel regular stock specifications, the MOQ is as low as 1 piece, and overseas sample trial orders are supported. For regular stock specifications, quality inspection and shipment are completed within 24–48 hours after payment confirmation. Large-volume full-container orders are uniformly stacked on fumigation-free solid wood pallets and packaged with multi-layer protection such as PE dust-proof film, anti-scratch protective film, anti-collision protective sleeves, export cartons, and waterproof stretch film, complying with customs export inspection standards. Customization is supported for customer-specific English shipping marks, LOGOs, specification labels, and batch numbers. For specific delivery times and packaging requirements, please contact us for confirmation.
Service & Support
We provide pre-sales technical selection support for B2B customers worldwide purchasing pipe-type lap joint stub ends, including working condition selection, material matching, pressure grade adaptation, flange pairing, and technical guidance for equipment connection and installation. Before leaving the factory, products undergo multiple quality inspections such as fine appearance inspection, precise dimensional re-inspection, end face flatness testing, material spectral verification, and hydrostatic pressure testing. For any factory production quality defects, free returns and exchanges and free replacements are supported. After-sales service provides technical Q&A on welding protection, sealing surface protection, and pipeline operation and maintenance, full-process logistics tracking for orders, and assistance for overseas customers with customs clearance and receipt of goods. The product warranty period is 18 months. During the warranty period, quality problems caused by non-human damage are repaired or replaced free of charge, with 7×24-hour foreign trade after-sales response.
FAQ
What is the difference between pipe-type lap joint stub ends and stamped lap joint stub ends?
The controlled flanging short piece is turned from seamless pipe material, with no weld seams, high precision, and good sealing surface flatness, making it suitable for working conditions with high requirements for sealing performance and precision. The stamped flanging short piece is formed by hot stamping, with high cost-effectiveness, making it suitable for general working conditions. For high-end projects or clean pipelines, the controlled type is preferred.
Can the controlled flanging short piece be used in clean pipelines?
Yes. The controlled flanging short piece adopts an integrated seamless structure, with no welding slag, no interlayers, and no impurity precipitation, making it suitable for pure water, pharmaceutical, and food clean pipeline networks. If a mirror-finish precision-turned sealing surface or internal and external polishing treatment is required, please contact us to confirm a customized solution.
Does the controlled short piece support high-pressure working conditions?
The controlled LP long type is suitable for medium- and high-pressure process pipelines, while the SP short type is suitable for low-pressure conventional pipeline networks. The specific selection needs to be determined according to parameters such as the pressure rating, temperature, and medium of the actual working conditions. Please contact us to provide working condition information so that we can assist with selection.
Can non-standard custom sizes and materials be provided?
We support precision customization of non-standard lengths, widened flanges, thickened wall thickness, and special materials. We can carry out one-on-one precision machining production according to customer drawings, samples, and technical agreements. Materials can be customized, including 2205 duplex steel, 15CrMo alloy steel, copper-nickel alloy, etc. Please provide the specific dimensions and quantity so that we can assist with the quotation.
Can a full set of certificates be provided for export?
We can provide customs clearance documents such as 3.1 material certificates, spectrum reports, CE certification, quality inspection reports, and certificates of conformity. For the specific types and number of copies of certificates required, please contact us to confirm.
