Why flanges fail at oil and gas facilities: real examples and solutions 

Flanged connections are a key element of pipelines in the oil and gas and chemical industries. Despite their reliability, accidents and leaks do occur in practice. Often this is not due to the quality of the flange, but to a violation of the installation, operation or maintenance technology.

Below are real examples of problems and how to prevent them.

Example 1: Leakage due to improper installation

One oil facility used flat weld flanges on the high pressure line. As a result, the weld and bolts were subjected to excessive stress, resulting in microcracks and gradual leakage.

Solution:replace flat flanges with welded ones (Weld Neck), ensure uniform tightening of the bolts with a torque wrench and control the parallelism of the flange surfaces.

Case Study 2: Flange Corrosion in an Aggressive Environment

In the chemical shop, accelerated corrosion of carbon flanges in contact with an acidic environment was discovered. The flanges began to lose their tightness after just a few months of operation.

Solution:replace flanges with stainless steel or alloy steel, and use chemically resistant gaskets.

Example 3: Incorrect choice of gasket and bolts

Standard rubber gaskets and regular bolts were installed on the steam and high pressure pipeline. After a short time, steam leaked and the bolts became deformed.

Solution:use gaskets designed for high temperatures and pressures, as well as bolts with the appropriate strength class.

Example 4: Non-compliance with standards and tolerances

On one project, flanges were purchased without testing to ANSI and DIN standards. The hole sizes and thicknesses did not match the pipeline, causing delays and additional rework costs.

Solution:work only with manufacturers who strictly comply with international standards and provide quality certificates.

Conclusion

Real cases show that most problems with flanges are not related to the product itself, but to:

• incorrect choice of type and material

• violation of installation technology

• non-compliance with standards

• using unsuitable gaskets and bolts

To avoid accidents and leaks, it is important:

1. Carry out a careful selection of the flange type for the operating conditions

2. Select materials based on pressure, temperature and chemical environment

3. Comply with standards and approvals

4. Install bolts and gaskets correctly

5. Work with trusted manufacturers

The use of these measures will significantly extend the life of the flanges and ensure the safety of the entire pipeline system.