Welding neck flanges

Weld-on neck flanges - an essential element of industrial installations

Weld neck flanges are key components in pipeline systems.   They provide tight and durable connections between pipes. They are used in many industries. They are commonly used in water, gas and chemical installations. Their main advantage is the possibility of easy disassembly of connections.

Our offer includes a wide selection of neck flanges. Models made of various materials are available. We offer steel, stainless steel and acid-resistant flanges. We also have plastic flanges for special applications.

Weld Neck Flange Types and Applications

Weld neck flanges vary in shape and purpose.   The most common types are:

• Flat flanges - universal, for low and medium pressures
• Convex seat flanges - for higher pressures and temperatures
• Grooved flanges - for chemically aggressive media
• Blind flanges - for closing the ends of pipelines

The selection of the appropriate type of flange depends on many factors. The type of medium, operating pressure and temperature must be taken into account. The requirements for tightness and durability of the connection are also important. In case of doubt, our consultants will be happy to help you choose.

Our experience has shown that neck collars perform well in difficult conditions.   We recently used stainless steel flanges on a project for a large chemical plant. They withstood aggressive environments and extreme temperatures.

Weld Neck Flanges - Key Parameters and Standards

When selecting weld neck flanges, there are several important parameters to consider:

• Nominal diameter (DN) - corresponding to the pipe diameter
• Nominal pressure (PN) - defining the maximum working pressure
• Material of manufacture - e.g. carbon steel, stainless steel, acid-resistant steel
• Manufacturing standard - e.g. EN 1092-1, ASME B16.5
• Rebate type - flat, convex, with groove

At Onninen we attach great importance to the quality of the products we offer.   All our neck collars meet strict European and international standards. They have the necessary certificates and material approvals.

We often come across the question about the differences between EN and ASME standards. Flanges according to EN 1092-1 are commonly used in Europe. On the other hand, the ASME B16.5 standard is popular in the USA and some non-European countries. They differ slightly in dimensions and markings.

In our daily practice, we see a growing demand for high-pressure flanges. They are essential in modern industrial installations. That is why we are constantly expanding our offer with flanges for increasingly higher working pressures.

Installation and operation of weld neck flanges

Correct installation of neck flanges is critical to installation safety.   The welding process requires appropriate qualifications and experience. The correct electrodes and welding parameters must be used. Proper surface preparation is also important.

In the case of reorganization of industrial installations, the question most often arises about the reuse of flanges. Our experience shows that this is possible under certain conditions. The flanges must be in good technical condition, without mechanical damage.

Onninen recommends the use of specialist gaskets for flange connections. They provide optimum tightness and durability. In our offer you will find a wide selection of gaskets for various media and working conditions.

Proper use of neck flanges requires regular inspection and maintenance.   The tightening torque of the connecting screws should be checked. It is also important to check the condition of the sealing surfaces. If any irregularities are noticed, it is necessary to replace the damaged elements immediately.

Many customers ask us about the possibility of reconditioning neck flanges. In some cases, this is possible by mechanically machining the sealing surfaces. However, it is always worth considering whether it would not be more cost-effective to replace with a new element.

At Onninen we offer comprehensive advice on the selection and use of neck flanges. Our specialists will be happy to help you choose the optimal solution. We also provide technical support during the assembly and start-up phase of the installation.

Weld neck flanges are critical products for the safety of industrial installations.   That is why it is so important to choose a proven supplier. At Onninen, we focus on the highest quality and reliability of our products. We invite you to familiarize yourself with our full range of flanges and accessories.