Long-radius flanged elbows are among the most commonly used standard elbows in pipeline engineering, with the industry designation LR and a bending radius R=1.5D. Compared with short-radius elbows, their curvature is gentler, and when the medium passes through, turbulence and pipe-wall scouring are smaller, which helps reduce fouling, vibration, and local pressure drop, making them suitable for long-distance transportation, high flow rates, and continuously operating pipelines. The flanges at both ends can be directly connected to pipes, valves, and pressure vessels by bolts and sealing gaskets, without the need for on-site welding, making later maintenance, cleaning, and modification more convenient. We produce according to standards such as GB/T12459, GB/T9113, ASME B16.9, and ANSI B16.5. Materials can be selected from carbon steel, stainless steel, alloy steel, plastics, etc. Pressure ratings cover PN6~PN100 and Class150~Class1500, suitable for media such as water, steam, oil products, gas, acid-base chemical fluids, and sewage.
Overview
The long-radius flanged elbow is a pipeline direction-changing fitting with flanges at both ends, and its bending radius is equal to 1.5 times the nominal diameter of the pipe, with the industry code LR. It relies on a gentle bending arc to reduce medium flow resistance and pressure loss, and to reduce pipeline turbulence, scaling, and vibration. The flanges at both ends can be directly connected to pipes, valves, and pressure vessels by bolts with sealing gaskets, without the need for on-site welding, making assembly and disassembly convenient and facilitating later pipeline maintenance, cleaning, and modification. We produce according to standards such as GB/T12459, GB/T9113, ASME B16.9, and ANSI B16.5, with a wide coverage of materials and pressure ratings, suitable for most mainstream pipeline engineering scenarios.
Key Features
The most prominent feature of the long-radius flanged elbow is the 1.5D long-radius gentle bending arc design. Compared with short-radius elbows, the medium flows more smoothly, and turbulence and pipe wall wear are lower, which helps reduce pipeline scaling, vibration, and local pressure drop, making it suitable for pipelines operating continuously over the long term. The integrated flange structure eliminates the on-site welding step, making installation and disassembly more convenient, and no hot work is required during later maintenance, cleaning, and modification. Product diameters range from DN15 to DN1200, wall thickness covers SCH20 to XXS, pressure ratings range from PN6 to PN100 and Class150 to Class1500, and corresponding choices are available for commonly used carbon steel, stainless steel, alloy steel, and plastic materials.
Applications
In civil and municipal applications, long-radius flanged elbows are used in urban water supply and drainage networks, residential fire protection systems, central air-conditioning HVAC circulation systems, municipal heating pipelines, and rainwater and sewage collection and transmission pipelines. In industry, they appear in chemical acid and alkali transmission pipelines, oil and natural gas transmission pipelines, high-temperature and high-pressure thermal pipelines in power plants, factory cooling circulation systems, clean pipelines in food and pharmaceutical production, and environmental protection sewage treatment projects. For long-distance transmission, high-flow-rate media, and pipelines operating without interruption, long-radius elbows are a common choice. They are also often used in densely piped machine rooms, equipment connection pipelines, outdoor open-air pipelines, and buried long-distance transmission pipelines.
Specifications
The bending radius is fixed at R=1.5D, standard angles include 45°, 90°, and 180°, and special angles such as 22.5°, 60°, and 120° can also be customized. Diameters cover DN15-DN1200 (1/2 inch-48 inch), and wall thickness supports SCH20, SCH40, SCH80, STD, XS, and XXS. Implementation standards include GB/T12459, GB/T9113, ASME B16.9, ANSI B16.5, and the HG and SH series. Pressure ratings are PN6-PN100 under Chinese standards and Class150-Class1500 under American standards. Commonly used materials are 20#, Q235B, and Q345B carbon steel, 201, 304, 304L, 316, and 316L stainless steel, as well as alloy steel and plastic. Flanges can be selected in forms such as plate flat welding, neck flat welding, and neck butt welding. For other materials and special specifications, please contact us for confirmation.
Purchasing & Delivery
Conventional in-stock standard specifications have a minimum order of 1 piece, covering commonly used specifications such as 90° long radius, PN16/PN25, carbon steel, and 304 stainless steel, suitable for sample procurement, sporadic replenishment, small-batch wholesale, and large-volume centralized procurement for projects. The warehouse keeps standard stock on hand and ships within 24 hours after order confirmation. The delivery time for non-standard customized orders is determined according to drawings and quantity; please contact us for confirmation. Packaging provides graded protection according to specifications: small pieces DN15-DN100 use hard cardboard boxes, medium diameters DN125-DN400 use bubble wrap plus stretch film for reinforcement, and large diameters DN450 and above use solid wood pallets for fixation plus rainproof film. Carbon steel pipe fittings are sprayed with anti-rust oil before leaving the factory, and stainless steel pipe fittings are packaged separately in isolation. Export fumigation wooden pallets, waterproof packing, and customized shipping marks are supported.
Service & Support
We provide free pre-sales selection guidance, working condition matching, parameter verification, drawing confirmation, and budget quotations. During sales, we track production progress, quality inspection status, and shipping logistics information in real time. After sales, we provide installation technical guidance, use and maintenance recommendations, and troubleshooting answers. Conventional products have a uniform 12-month warranty period. During the warranty period, if quality problems such as cracking, deformation, leakage, or material inconsistency occur due to non-human factors, we support free replacement, free reshipment, and bear the round-trip logistics costs. For large-volume engineering projects, online technical disclosure and remote technical support can be provided. Unused standard products with intact packaging support seven-day no-reason return and exchange. After-sales issues are connected within 2 hours, and a solution is given on the same day.
FAQ
What is the difference between a long-radius flanged elbow and a short-radius elbow?
Long-radius elbow R=1.5D, with a gentle curvature, low flow resistance, low pressure drop, and strong erosion resistance, suitable for conventional and industrial high-pressure long-distance pipelines. Short-radius elbow R=1.0D, occupies little space, but has high resistance and strong erosion, mostly used for low-pressure, low-speed, or space-constrained temporary pipelines. In engineering, long-radius elbows are preferred.
Do long-radius flanged elbows require on-site welding?
No. Both ends of the product come with flanges, which are directly connected to pipelines, valves, or pressure vessels via bolts and sealing gaskets, eliminating the on-site welding process, making assembly and disassembly convenient, and facilitating later maintenance, cleaning, and modification.
What materials and pressure ratings can you provide?
Common materials include 20#, Q235B, Q345B carbon steel, 201, 304, 304L, 316, 316L stainless steel, as well as alloy steel and plastic. Pressure ratings cover PN6-PN100 and Class150-Class1500. For special materials or higher pressure requirements, please contact us for confirmation.
What are the minimum order quantity and delivery time?
Standard specifications in regular stock start from 1 piece, covering commonly used specifications such as 90° long radius, PN16/PN25, carbon steel, and 304 stainless steel. The warehouse keeps regular stock, and shipments are made within 24 hours after order confirmation. The delivery time for non-standard custom orders is determined according to the drawings and quantity; please contact us for confirmation.
Can you customize special angles or non-standard sizes?
Yes. We support customization of conventional angles of 45°, 90°, and 180°, as well as special angles such as 22.5°, 60°, and 120°, and can also customize extra-large diameter, special thick-wall, and thin-wall non-standard sizes. Flange sealing faces can be selected as raised face, male and female face, tongue and groove face, and ring joint face. Please provide drawings or operating condition parameters, and we will assist with confirmation.
