UNS N06625 Weld Neck Flange

In industrial pipeline systems with harsh environments such as high pressure, strong corrosion, and high temperature, the reliability of pipeline connection fittings directly determines system safety. UNS N06625 weld neck flange is widely used in high-end industrial pipeline systems due to its superior performance.

The UNS N06625 weld neck flange is our produce have strict requirements from raw material procurement inspection to process control. Each piece undergoes dimensional testing and spectral composition analysis to ensure compliance with ASTM B564 standards. As the standard grade corresponding to Alloy 625, it contains over 58% nickel and is supplemented with chromium, molybdenum, and niobium alloy elements. It is not only resistant to strong acid and seawater corrosion, but also maintains excellent mechanical strength at high temperatures of 650 ℃, with a tensile strength of over 827MPa.

ASTM B564 UNS N06625

UNS S06625 is a nickel based alloy material, also known as Inconel 625. Its core component contains more than 58% nickel, and additional elements such as Cr(20-23%), Mo (8-10%), Nb+Ta (3.15-4.15%) are added. This ingredient combination endows it with excellent high temperature resistance and corrosion resistance, and can work stably in oxidizing and reducing environments, especially with outstanding resistance to corrosive media such as chlorides and organic acids.

There are mainly two corresponding American material standards: one is ASTM B443, which is for nickel alloy seamless pipes; The second is ASTM B564, which specifically specifies nickel alloy forgings, while UNS N06625weld neck flange, as forged pipe fittings, must strictly follow the ASTM B564 standard for production and quality testing. This standard specifies the requirements for chemical composition deviation, mechanical properties (normal temperature tensile strength ≥ 827MPa, yield strength ≥ 414MPa), non-destructive testing, etc. of the material to ensure that the flange performance meets the standards.

Chemical Composition

Mechanical Properties

What is the Meaning of UNS N06625 Weld Neck Flange

Specification

The nominal diameter of UNS N06625 weld neck flange covers DN15-DN1500, and the nominal pressure covers Class 150-Class2500, which can adapt to different industrial pipeline system requirements. From the perspective of sealing surface types, they include protruding surface (RF), concave convex surface (MFM), tenon groove surface (TG), etc., which meet different sealing accuracy requirements. Among them, protruding surface flanges are the most commonly used and suitable for general sealing scenarios, while tenon groove surface flanges are suitable for high-pressure, flammable and explosive medium working conditions.

Dimension of ASME B16.5 WN Flange

Following the ASME B16.5 American standard for size, taking the DN100 Class150 butt welded flange as an example, the outer diameter is 228.6mm, the center circle diameter of the bolt hole is 190.5mm, the number of bolt holes is 8, the aperture is 19.1mm, the flange thickness is 23.9mm, and the neck height is 52.9mm. 

The standard has strict limits on size tolerances, such as an outer diameter tolerance of ± 1.6mm and a bolt hole position tolerance of ± 0.8mm, to ensure that the flange is compatible with the pipeline and bolts, and to avoid installation deviations affecting sealing performance.

Class 150 WN Flange Dimension and Weight

Characteristics of Alloy 625 WN Flange

Firstly, it has high temperature resistance. At a high temperature of 650 ℃, its tensile strength can still maintain over 70% of that at room temperature, making it suitable for long-term use in high-temperature pipeline systems;

Next is corrosion resistance, which has a corrosion rate of less than 0.1mm/year in harsh environments such as seawater and hydrochloric acid, far superior to ordinary stainless steel;

In addition, it also has good welding performance, with reduced performance degradation in the heat affected zone after welding, and excellent low-temperature toughness, with no risk of brittle fracture at -196 ℃.

Application

Compared to ordinary stainless steel butt welding flanges, UNS N06625 weld neck flange do not require frequent replacement and have a service life of 10-15 years, reducing maintenance costs;

Its high-strength characteristics allow for reducing flange thickness, reducing the overall weight of the pipeline system, and saving installation space;

At the same time, excellent sealing adaptability can reduce medium leakage rate, meet industrial safety and environmental protection requirements, especially suitable for high-risk working conditions.

Development Prospects

With the development of high-end and green industries, the demand for UNS N06625 weld neck flange continues to grow. In the field of new energy, the demand for high-temperature and corrosion-resistant flanges in hydrogen energy transmission pipelines and photovoltaic silicon material production equipment has increased, which can meet the requirements of high-pressure hydrogen energy transmission (35-70MPa) and strong acid environments; In the field of nuclear power, the promotion of third-generation and fourth generation nuclear power technologies requires a large number of flanges that can withstand radiation and high temperatures. UNS N06625 has become the preferred choice due to its stability performance;

In addition, with the increasing number of seawater desalination projects worldwide, their anti seawater corrosion properties will also expand their application scenarios. In the future, with the optimization of alloy smelting processes and gradual cost reduction, UNS N06625 weld neck flange will be popularized in more high-end industrial fields.