Table of content
Introduction
Insulated flanges are usually made of non-conductive materials. Because in the pipeline industry, not only gases and fluids are transported, but sometimes electrical currents are also transported, which may cause corrosion. Insulated flanges can effectively isolate and protect pipeline systems from electrolytic corrosion. But what are the specific characteristics of insulation flanges, and what are their working principles and performance? With these questions in mind, let’s take a look at this product.
What is an Insulating Flange?
Insulated flanges are also a type of flange connector used for connecting pipeline systems. Its material is mainly non-conductive (gaskets, sleeves, and washers), and this material flange can effectively prevent current from flowing between various pipelines.
By using insulated flanges to cut off the edges between electrical components, pipelines can be protected from the effects of electrolytic corrosion. This feature is mostly applicable to underwater or underground pipeline systems.
What is the Purpose of an Insulating Flange?
The main purpose of insulated flanges is to prevent electrolytic corrosion of pipelines caused by the influence of current.
It mainly includes the following aspects:
- Prevent stray currents from passing through pipelines.
- Controlling corrosion typically requires coordination with cathodic protection systems.
- Electrical isolation is achieved between various parts of the pipeline through insulated flanges.
- In pipeline systems such as oil and gas, their safety can also be increased.
Due to the lack of insulation, current passing through the steel will cause accelerated corrosion of the steel.
Where are Insulating Flanges Used?
The main function of insulated flanges is to isolate electrolytic corrosion.
Therefore, it is commonly used in the following industries:
- Oil and gas pipeline system
- Water supply pipeline system
- Chemical pipeline system (mainly used for handling corrosive liquid pipelines).
- Refinery and power plant
- Underground pipeline system
Any pipeline that needs to be connected to the power system will be used for insulating flanges.
Difference Between Insulating Flange and Regular Flange
There is no essential difference between insulated flanges and ordinary flanges, the main difference is that insulated gaskets are added during the installation of insulated flanges.
- Ordinary flange: Connecting two pipes together.
- Insulated flange: When connecting two pipelines, an insulated gasket is used as the middle gasket.
In addition to adding insulation gaskets, insulation flanges can also achieve insulation in the following ways:
- Use insulation gaskets during installation.
- The use of insulating sleeves is to cover the bolts during installation.
- Use insulated gaskets.
What is an Insulating Flange Kit?
An insulating flange kit electrically isolates other pipeline components, thereby reducing electrolytic corrosion.
The kit includes:
- Insulating gaskets
- Bolt sleeves
- Insulating washers
- Steel washers
Types of Insulating Flanges
Depending on the application, different designs are available:
- Full-surface insulating flanges: The insulating gasket covers the entire flange surface, providing optimal insulation.
- Ring-shaped insulating flanges: A gasket is used around the flange’s inner hole and are primarily used in low-pressure systems.
- RTJ (Ring-Shaped Joint) insulating flanges: A special groove is used for sealing and are primarily used in high-pressure piping systems.
Each insulation method depends primarily on the pressure and temperature of the pipeline and the type of fluid.
Standards for Insulating Flanges
Like ordinary flanges, insulating flanges must comply with flange manufacturing standards. These include, but are not limited to:
- ASME B16.5: American Standard Flange Standard, primarily specifying flange dimensions and pressure ratings.
- ISO9001: Quality Pipeline Certification Standard.
- NACE Standard: Primarily a production standard for the oil and gas industry.
Advantages of Using Insulating Flanges
- Effectively prevent electrolytic corrosion.
- Extend pipeline service life.
- Improve pipeline safety.
- Compatible with cathodic protection systems.
- Improve cost-effectiveness.
Summary
Insulating flanges are similar to ordinary flanges, except that they are also insulated during installation using insulating gaskets, sleeves, and washers. This special pipe connection method effectively prevents the flow of current between pipes and effectively prevents electrolytic corrosion.
In short:
The only difference between an insulating flange and an ordinary flange is whether the gasket between the flange connections is made of insulating material.
Insulating flanges primarily reduce corrosion, improve safety, and reduce maintenance costs. They are particularly useful in offshore projects and corrosive oil, gas, and some chemical projects.
