Small pieces of mechanical equipment flanges continually play a vital role across numerous industries and applications.
In essence, we use flanges to connect pipes to each other, with flanges also found in valves and specific application fittings too.
Due to the nature of varying pipe materials and application settings, flanges come in various shapes, sizes, and materials to suit their intended use.
In this post, the two SSP ring-type joints we will be looking at further are the blind and blank flanges. Examining their differences, the applications where these types of flanges are most suited, and the benefits they can bring to specific applications.
Flange covers
We use flanges to connect piping systems and prevent liquid or gas from escaping/leaking from these systems/valves.
Flanges are often bolted onto the pipes (however, some flanges can also come without bolt holes if required), and the sealing element is achieved when used alongside the most appropriate gasket.
Found in all pipeline engineering applications, flanges can be welded, threaded, or clamped and are also suitable for the chemical industry, construction, and petroleum industries.
Blind Flanges
A detachable sealing device, a blind flange, is a solid flange that industries use (typically within piping systems) to completely shut off a section of pipe or, if nozzles within applications aren’t being used, to seal the nozzle end.
Blind flanges are used at the end of the pipe to close it off completely and act as a flange cover. They have no centre hole, so nothing can continue to flow through them.
Blind flanges are available in various diameters and classes. This type of flange can also have a raised or flat face, and it’s important to note that if you opt for a raised blind face, you should use a standard ring gasket alongside, and for flat-faced flanges, a full face gasket should be used (as flat-faced flanges are not designed to handle the bending force that a ring gasket can produce).
It’s also interesting to note that blind flanges can also be used to replace a butt weld cap if you require an extension of the piping line in the future.
Depending on the piping system and joint, these flanges can be manufactured as drilled, slip-on, or threaded flanges and are placed between the front and the back of shut-off valves or between two flanges.
This type of ring-type joint gasket is available in:
- Carbon steel
- Alloy
- Copper
- Aluminium
- Stainless steel, and
- Plastic.
Benefits of a blind flange
- Offers a good sealing performance
- Reliable
- Can isolate/cut off to a high standard
- Easy to replace
- Easy to carry out maintenance on
(If you’re enjoying reading this article, why not check out our latest post on “Octagonal ring type joints” to learn more).
Blank Flanges
Now, we come to blank flanges.
Blank flanges have solid surfaces with no holes, and these types of RTJs are machined to the piping system or finished product to achieve the same outcome—providing a high-quality seal.
Blank flanges are flat and circular flanges with no openings. We often use blank flanges when systems require maintenance or testing, or even if you need a future connection, blank flanges can be the most suitable choice.
Available in various materials and sizes to suit a range of applications, blank flanges can still allow flow through the system as these are considered a temporary sealing solution.
Benefits of a blank flange
- Great if you require a short-term sealing solution
- Provides a high level of sealability as it is bolted to the pipe system
- Suitable for high-pressure applications
- Also known as a blanking flange, it can provide a temporary solution, blanking off systems while vital maintenance work is carried out
- It is the most typical representation of a standard flange.
Key differences between blank and blind flanges
Blind flanges are permanent, whereas a blank flange can be put in place for temporary maintenance.
Blind flanges are manufactured in steel, stainless steel, copper, or plastic. Blank flanges can be manufactured in any material compatible with the application it is intended for.
Blind flanges seal off a piping system completely. Blank flanges have no openings and are used as a temporary stop-gap.
Ring type joints
Whatever flange you choose, it’s vital that it is the right one for the application for which it is intended.
This means taking into account material selection, cost, future requirements, what the application and piping system is susceptible to, and more.
The good news is we’re here to help.
At Specialist Sealing Products (SSP), our team has years of experience and industry knowledge in the best sealing ring-type joints, gaskets, and flanges to provide you with the answers to your questions.
Helping you to make the most informed decision and the best flange selection for your piping system, speak to one of our experts today.
We stock a full range of gaskets and flanges in various sizes and materials to suit all industry sectors and applications.
Check out our stock online, or alternatively, email us with your requirements and questions to sales@specialistsealingproducts.co.uk.
