Threaded Flanges

Threaded flanges are designed to connect threaded pipe without the need for welding. Because no welding is required during installation, they are frequently specified for piping systems where hot work should be avoided or where future disassembly is expected. PipingMarket.eu supplies threaded flanges in a wide range of dimensions, pressure classes and materials, including a complete range of SA105/N, SA350 LF2, SA694 F52 and SA694 F65.

How does a threaded flange work?

Unlike welded flange designs, a threaded flange is screwed directly onto externally threaded pipe. The sealing surface is created by the flange facing and gasket, while the threaded connection secures the flange to the seamless pipe. In certain applications, a seal weld may be added after installation to improve leaktightness, although the primary purpose of the flange remains a threaded mechanical connection. Threaded flanges are typically manufactured according to ASME B16.5.

Advantages and limitations

One of the main advantages of threaded flanges is that installation does not require welding equipment, making them suitable for locations where welding is impractical. They also simplify maintenance because the connection can be dismantled more easily than a welded joint. However, threaded flanges are generally intended for low-pressure and low-temperature service. They are not recommended for systems exposed to severe vibration, cyclic loading or high thermal stresses.

What is the difference between a threaded flange and a slip-on flange?

Many engineers ask what the difference between a threaded flange and a slip-on flange is when selecting a flange connection. A threaded flange connects to threaded pipe without welding, whereas a slip-on flange slides over the pipe and is secured by fillet welds on both sides. Another difference between a threaded flange and a slip-on flange is the operating conditions for which they are intended. Threaded flanges are selected for lower-pressure utility systems or installations where hot work should be avoided. Slip-on flanges are generally preferred for permanently welded process piping.

Related flange solutions

Different types of flanges are often combined within the same piping system to meet specific application and performance requirements. Complete piping packages may include:

• raised face flange solutions for gasketed sealing surfaces;
• socket welding flanges for small-diameter, high-pressure systems;
• lap joint flange assemblies for piping requiring frequent dismantling;
• long welding neck flanges for high-pressure and critical service;
• swivel flanges for offshore and subsea piping connections;
• A694 F65 flanges for high-strength pipeline applications.

Source threaded flange solutions

Whether you require standard threaded flanges or other piping products, submit your technical specifications through our online RFQ platform. Our specialists will review your material grade, dimensions, pressure class and applicable standards to help identify the most suitable solution for your application. Through our international supplier network, we support projects of all sizes.