Blind Flange

Blind Flange


A flange is a protruded lip or ridge, which helps in connecting different types of pipes, valves, and other equipment in a piping system. They also provide support to the system and allow for an easy attachment within the system. These modules can be readily bolted or welded depending on the requirements of the application. There are different types of flanges each, having its own unique properties and functions.

It is a component, which doesn’t have a head or a protruding hub. They act as a barrier and seal of high-pressure valves and nozzles within a system. It acts as a plug or cap and terminates the flow across the system. The components can be also utilized to cut off the supply or used when additional modifications are planned on the line. The modules are made of a bolting system whose face thickness corresponds to that of the enclosing. They require little to no machining and are very heavy due to the absence of a bore. The range of products can be welded or bolted depending on the requirement. If they are bolted, they offer an opportunity to clean and inspect the interior of the entire system.


  • ASME : B16.5
  • ASTM : A182
  • Pressure Class: 150# to 2500#

What is the difference between blank and blind flange?

A blank flange and a blind flange both perform similar functions of stopping the flow of gases and fluids in a piping system. However, there are some differences, which separate both of them from each other. A blind flange induces a dead end to the tubing flow. In comparison, a blank flange has to be machined on the system to make it into a finished product.


These components which are produced without a hub can be availed either as a raised face or flat face module. Unlike other flanges, their main role is to be fitted at the ends of a piping module and eliminate the flow. They are widely utilized to check pipe pressures and creating an access point to the interior of the module. Apart from this, they act as a temporary seal within the system, which enables modifying, and repairs to take place within the line. They can also be used to form a seal for a long periods. This seal helps terminate the flow completely or add additional fittings and components.

How does it work?

The most important function before imitating any process is selecting the right component. Before this system starts working properly the, best flange material along with its correct dimensions will dictate the working quality of the flange. Better the material better will be the tolerances against various elements. The main function of this flange is to stop the flow within the system. This can either be permanent or temporary. It also helps in renovation work on the pipeline when new flanges or systems are added.

Do blind flanges need gaskets?

These components are generally bolted onto different elements. The utilization of a gasket helps in creating a tighter seal and locking the system more precisely. It also fills any extra space between the faces of the flange and helps in preventing any gaseous fluid leakage. Many across the industry prefer a gasket with a solid center. However, a standard gasket is very decisive and helps prevent water or gases from getting to the flange thereby, preventing any corrosion or failures.

What is a raised face?

There are two types of flanges available within this component namely a raised face and flat face flange. The RF component is the most common type of face used in the system. This type of module is designed with a raised surface near the bolting circle wherein the gasket is placed. This helps in concentrating the contact pressure onto this area resulting in increased strength of the seal. The machine serrated finish easily bites on the gasket surface to commiserate an excellent module which helps to create a tight seal. They can be utilized for high as well as low pressure and temperature applications. This is why they are commonly seen in petrochemical and in oil and gas pipelines.