Importance of Flanges in Piping Systems
Flanges are the most important component for the piping system to make proper joints and valves. You can get a detailed explanation about flange dimensions in simple terms. Starting till what are flanges till why their dimension, size etc matters is explained in this blog. Are you new to this field or gained some expertise? In any of these cases, you can refer to this guide and select the best suitable one for your application.
What are flanges? Flanges are designed with components like a flat disc having holes to insert the bolts in its circumference. It helps in better connection of the pipes, valves and more. Flanges help to make connections in a steady way for long term usage. Even these are available in different dimensions, jobs, materials and sizes. You can distinguish on the basis of this criteria and select the one for application in the piping system.
Weld Neck, Slip-On, Blind, Lap Joint, etc.
Take a quick overview for description for different type of flanges as follows:
Weld neck flange
These are easy to identify because of the presence of the long tapered neck. It allows a proper pipe fitting with flange to get better sealing. The tapered neck helps a person to get reinforcement in many areas. It includes application at high pressure, elevated temperature or sub zero levels. You can find the smooth transition between tapered end of weld neck flange to thickened pipes. This transition is proven beneficial for line expansion, bending or any other variable forces. Weld neck flanges are attached with pipe along with a long tapered head. The flange matches with the bore of the pipe to reduce turbulence and erosion of fluid flowing.
These flanges are welded or bored inside the mating pipe to make a seal which does not restrict the flow of products. This design works to restrict the turbulence and reduces the chances of erosion and stress.
Slip-On flanges
These flanges are made slip into the pipe and hence named so slip-on flanges. It is further welded on the outer as well as inner side of the connection to make a secure sealing. It requires a bit of space to get proper installation with the welding process.
Socket weld flange
This is suitable for the small size high pressure area in industries. The connection of flange with the pipe occurs with 1 fitted weld made on the outer side. But you need to make proper space between the flange or pipe for enhanced sealing. This connection is made weld at a depth of about 1.6mm away from the shoulder of the socket. The main aim for the flange installation is to distribute the stress over the bottom area to avoid problems of failure.
Lap joint flange
Lap joint flanges are made with common dimensions when compared with other flanges. It has the radius at intersection point with a flange face and bore. Hence, this design allows the easy accomodate of the flange part at the stub end. The holding ability of these flanges is quiet enough to give a stable seal.
Threaded flange
The main advantage of threaded flange is to make a connection with pipe without need for welding. Sometimes, in industries threaded flange is joined with seal weld to make a good connection. You can locate all of this in different dimensions, sizes, pressure ratings and more used in smaller sizes. It is most applicable to pipes having thickness of about 80% of ASME B36.10. Threaded flange is able to withstand the pressure of about 250 PSI and temperature of about 220 degree celsius.
Blind flange
Blind flanges are used to blank off the pipe ends to get isolation in the piping system. It gives a perfect sealing with pressure openings. Blind flanges are available in larger sizes to withstand internal pressure and bolt. However, it is able to hold the stress and bending for near standard sides.
Flanges provide many of the benefits to industries as follows:
Connectivity
Flanges help to provide a secure connection with pipe to give reliable sealing. Hence, it is proven great for connectivity with flanges.
Versatility
These flanges are available in different dimensions, pipe, sizes, materials, pressure ratings and more. Hence, it is applicable in different places and proves versatile for industrial use.
Ease of maintenance
Flanges are proven easy to install as well as dismantle. Hence, these connections are proven great for frequent maintenance.
Pressure resistance
Flanges make an integral sealing in the piping system. It can withstand high pressure and temperature conditions.
Alignment
Different flange dimensions in mm helps in proper alignment of connection during installation. Hence, it reduces the chances of misalignment which can lead to leak conditions.
Cost-effective
Flanged connections are proven cost effective as compared with other types of connections. These are mainly installed in areas which need frequent maintenance or in larger pipes.
Standardizations
The flange helps to ensure interchangeability with components. Also, it helps in reduction of downtime for further replacements.
Overview of ANSI, ASME, DIN Standards
You would have frequently heard about different standards. Let’s get an overview of some of the common yet important flanges.
These are recognized as American National Standards Institute (ANSI) and American Society of Mechanical Engineers (ASME). Both standards are collaborated to set a primary use in North America. These standards notify about the material, pressure ratings, temperature ratings, dimensions, face typing and more.
DIN
This is a German institute of standardization well known as Deutsches Institut Fur Normung (DIN). Even this standard is accepted globally and covers similar information as ANSI.
EN
The European Committee for standardisation (EN) is accepted with members of the European union for flanges. This is almost similar to DIN but with some variations.
JIS
It is known as Japanese Industrial Standards (JIS) followed in Japan and some Asian countries. It helps to specify about dimension, material, requirement of testing etc in flanges.
Standardisation is important when selecting the flanges in industries. It is due to many reasons mentioned as follows:
Standardised flanges are important to different manufacturers for ensuring proper compatibility. This can help to simplify repair, maintenance and procurement in industries.
Standards are important for establishment of perfect sealing with reliability. It includes criteria like tolerance, testing procedures, material composition and more.
Further, it helps in ensuring compatibility, safety and reliability in the area of application. Thus, it helps in reducing downtime, preventing leaks and ensuring efficient sealing in the piping system. As mentioned earlier, standards help in defining the specific dimensions, materials, performance and more. Attach this standard to get a seamless integration and optimal performance in industrial operations.
The dimensions of the flange are selected on the basis of the size and pressure rating of the pipe. Take a general view for the dimension of the pipe and its respective pressure ratings.
This is the standard size used for describing the diameter of different pipes. The common size includes ½”, ¾”, 1”, 1 ¼”, 1 ½”, 2”, 2 ½”, 3”, 4”, 6”, 8”, 10”, 12” and more.
The dimensions of flanges give outer, inner, bolt circle diameter, bolt size and thickness and more. All of this is different with pipe size and pressure ratings. The pressure ratings come in varied classes like 150, 300, 600, 900, 1500 and even 2500.
Pressure ratings are crucial to consider in the flanges due to maximum pressure determination. Also, it notifies about specific temperature ranges to ensure the safety of the piping system with proper sealing. Refer to the checklist to know the importance of pressure ratings.
Common Materials Used (Carbon Steel, Stainless Steel, Alloy Steel)
Material Selection Based on Application
The selection of materials of flange depends upon different factors. It includes transport of fluid, operating conditions, requirements and more. Check out some common materials and its application in different industries.
This material is applicable to low temperature and high temperature areas. Hence, you can apply carbon steel on areas where corrosion resistance is not a primary issue. Industries like water, oil, gas and steam etc.
Stainless steel flanges are excellent to tolerate the corrosion. Hence, it is applicable to pipe carrying corrosive fluids like saltwater, chemicals, acids and more. Some common stainless steel grades which are proven perfect for flanges include 304, 316 and 321 etc.
Alloy steel flanges are suitable to tolerate high pressure, harsh conditions and temperatures also. It is applicable in industries like power generation, petrochemical, gas and oil etc.
Here is the step-by-step guide to install the flanges in particular applications.
Before you make any kind of installation check for defects, foreign materials or damage. Ensure you get a clean and free from debris region to get proper installation.
Choose a gasket material which is proven compatible with temperature, pressure and fluid application. Ensure to get a correct size and shape of flange while selecting it for a particular area.
Try to reduce the chances of misalignment. If this happens it can lead to causes of leaks, damage to application for flanges.
Select correct size and grade of bolts, nuts, washers and more as specified with flange standards. Tighten the bolts in a diagonal pattern in progressive manner to ensure uniform alignment of the gasket with the flange.
Check proper flange dimensions chart and torque values for proper tightening and adjustment of flanges. Over or under tightening of bolts may lead to distortions of the flange.
After completing the installation process, perform a final inspection test to ensure proper alignment, gasket compression and secured tightening of bolts.
Follow these quick maintenance tips to ensure the best practices with flanges.
Regularly inspect the signs for any damage, leak, corrosion, wear or tear in the piping system. Also, perform the test for integrity of seal, gasket compression, signs of degradation and more.
Make replacement with gasket as per need, to show up signs for damage, leakage or compression loss. Make use of the gasket made with appropriate material for further application.
Flanges have to tolerate many of the stressful conditions and thermal cycles which might loosen up the bolts over time. Check the torque value for specific flange on manufacturer specified value. It will help to maintain integrity of gasket compression.
Implement the corrosion protective measures on flange and pipe connection. It includes material selection, cathodic protection, coatings and more.
Provide proper training to personnel involved for installation and maintenance. This will ensure the procedure and safety measures as observed.
Keep updating with records for maintenance activities, repairs, inspection, compliance and more.
What are the differences between various flange types?
All of the flanges are different in design, size and have specific features for the particular application in the industrial area.
How do flange standards (like ASME and ANSI) differ?
There are many of the flange standards associated with each specific information. ASME is particularly applied for mechanical engineering practice.
What materials are best for specific flange applications?
Materials like carbon steel, stainless steel, steel alloy etc are best for specific flange application. It includes areas with high pressure, temperature, corrosion and more.
How do you choose the right flange size and pressure rating?
Refer to the flange dimensions chart pdf and match the right flange size with its pressure ratings.
What are the best practices for installing and maintaining flanges?
Proper cleaning, alignment, evenly tightening of bolts, regular inspection, documentation, replacement etc are best practices for installing and maintaining flanges.
A seasoned Electronics and Communications engineer, Amitkumar Miyani brings over 12 years of experience in Pipe Fitting Manufacturing to KMS. He plays a pivotal role in overseeing the Purchase, Sales, and Finance departments, ensuring operational efficiency and financial stability.
