Slip-On Flange

Slip On Flange is a type of flange with an inner diameter slightly larger than the outer diameter of the pipeline. It is connected by fitting it onto the outside of the pipeline and welding it in place. It is widely used in low-pressure to medium pressure pipeline systems. Its structure is simple and easy to install, making it a common connecting component in industrial pipelines.

The installation process of sliding flange is clear: first, insert the flange into the end of the pipeline, so that the pipeline extends a certain length beyond the flange sealing surface (usually 1/2 of the flange thickness), and then fix it with corner welding on the inside and outside of the flange. This double weld design ensures both sealing and enhances connection strength, making it suitable for pipelines ranging from DN15 to DN2000.

There are various material choices, and carbon steel (such as A105, Q235) is suitable for ambient temperature and low pressure scenarios; Stainless steel (304, 316) has strong corrosion resistance and is suitable for the chemical and food industries; Alloy steel pipe (12Cr1MoV) is used for high-temperature pipelines. The flange sealing surface is mostly flat (FF) or protruding (RF), which can be sealed with gaskets.

Compared with butt welded flanges, its advantages lie in low cost (about 60% -70% of the price of butt welded flanges), flexible installation (allowing for a small amount of axial deviation of the pipeline), but lower pressure resistance level (usually applicable to Class 150 to Class 300).

Typical applications include: water supply and drainage pipelines, low-pressure steam pipelines, ventilation systems, etc. The product must comply with standards such as ASME B16.5 and GB/T 9119. Before leaving the factory, it must undergo hydrostatic testing and dimensional inspection to ensure reliable quality.