Stamping reducer (also known as concentric reducer or variable diameter pipe) is a type of pipe connector formed through stamping process, used to connect pipes of different diameters and achieve smooth transition of pipeline system. It is widely used in engineering systems such as petrochemical, power, HVAC, water supply and drainage.

1、 Product Features

One time stamping forming, high structural strength: using cold/hot stamping technology, continuous metal flow lines, no welds (seamless structure), excellent compressive and fatigue resistance, suitable for medium and high pressure working conditions.

Low fluid resistance and smooth transition: The concentric design ensures a conical smooth transition on the inner wall, avoiding the generation of eddies or turbulence during medium flow and reducing system pressure drop.

High dimensional accuracy: The mold molding ensures that the outer diameter, wall thickness, and length tolerances are controlled within ± 0.5mm, making it easy for on-site butt welding installation.

There are various connection methods: mainly butt welding connection, but can also be customized with socket welding, thread or double clamping structure, suitable for different pipes and construction conditions.

Space and cost savings: Compared to welded assemblies, single stamping reduces the number of connection points, lowers the risk of leakage, and reduces installation time.

Material diversity and adaptability support customization of various materials, including carbon steel (Q235, 20 #), alloy steel, austenitic stainless steel, duplex steel, titanium alloy, Hastelloy, Monel, Inconel, and special metal customization.

Stainless steel stamped fittings have excellent corrosion resistance and are widely used in industries such as chemical, food, and pharmaceutical; Carbon steel pipe fittings are economical and practical, and are the preferred choice for municipal engineering and ordinary industrial pipelines; Alloy steel pipe fittings can meet the requirements of special working conditions such as high temperature and high pressure.

2、 Execution standards

national standard:

GB/T 12459-2017 "Steel butt welded seamless fittings"

GB/T 13401-2017 "Welded Steel Pipe Fittings"

Industry standards:

SH/T 3408-2021 "Steel butt welded fittings for petrochemical industry"

HG/T 21634-2022 "Reducing Pipes for Chemical Pipelines"

International standards:

ASME B16.9 (American standard butt welded pipe fittings)

DIN 2616 (German standard reducer)

ISO 3419 (International General Specification for Welded Pipe Parts)

All products must undergo non-destructive testing (such as RT, UT) and hydrostatic testing (1.5 times working pressure) to ensure compliance with safety requirements.

3、 Size specifications

注：标注方式为“DN大端×小端”，如DN100×80表示大端DN100、小端DN80；也可用英寸表示，如4"×3"。

弯曲长度通常为‌1.5D~2.0D‌（D为大端直径），以保证流体平稳过渡。

四、压力等级

‌公称压力范围‌：PN1.0MPa ~ PN420MPa（Sch5s ~ XXS）

‌常见等级对应‌：

‌Sch40‌：适用于PN1.6~2.5MPa，常规工业与建筑系统

‌Sch80/XS‌：适用于PN4.0~10.0MPa，高压蒸汽、石油管线

‌XXS‌：适用于PN10.0MPa以上或强腐蚀环境，如核电、深海管道

‌耐温范围‌：

碳钢：-20℃ ~ +400℃

不锈钢：-40℃ ~ +600℃

合金钢：可达+650℃（如15CrMo）

实际选型应结合设计压力、温度、介质特性，依据‌ASME B31.3‌或‌GB 50316‌进行强度校核，确保系统安全运行。