Features and Practical Application Scenarios of Neck Flat Welding Flange.

one：Basic structure and definitions

The Slip-On Flange (SO Flange) is a disc-like component with a central bore and a short conical hub. Its most distinctive structural feature is that the pipe can be easily inserted into its bore and secured with two fillet welds (inside and outside), creating a robust connection. This design offers greater strength than a flat plate flange.

Two: Core advantage - ease of installation

The primary advantage of the Slip-On Flange is its ease of installation and efficiency. Its bore is slightly larger than the pipe's outer diameter, allowing for minor adjustments and alignment during installation, which is highly beneficial for field work. The lack of need for complex bevel preparation lowers the technical threshold and labor costs.

Three: core advantage - economy

Among common flange types, the Slip-On Flange offers excellent cost-effectiveness. Its initial cost is lower than a Weld Neck flange, and when combined with faster installation and lower required welder skill, it becomes the preferred choice for large-scale projects with budget constraints and non-extreme service conditions.

four：Strength and limitations

Although stronger than a Plate Flange, the fatigue strength of a Slip-On Flange is still lower than that of a Weld Neck flange. Its stress distribution characteristics make it unsuitable for services with severe bending stresses, sharp temperature fluctuations, or high-frequency pressure cycling. Weld Neck flanges are preferred in such cases.

Five: Typical application scenarios - low-voltage public works

Slip-On Flanges are widely used in low-pressure and low-temperature utility piping systems. Common examples include plant cooling water circuits, fire water lines, low-pressure compressed air pipelines, and building HVAC water systems. These systems operate under stable conditions, typically at ANSI 150# or 300# ratings and below.

SIX:The importance of quality and certification

Regardless of the application, the quality of Slip-On Flanges is paramount. Ensure your supplier provides flanges that conform to ASME, ASTM, EN, or other relevant standards, with necessary Material Test Certificates (MTC) and third-party inspection reports. This is fundamental to ensuring the integrity and safety of the piping system.