5 Tips To Using A Steel Pipe Flange For The First Time

A pipe flange is a mechanical device which serves the purpose of joining pipes together. It can be in the form of a welding neck where it’s welded to the flange collar or threaded where it’s screwed to the flange. Other methods include the use of a lap joint to make connections using a stub end, or a socket weld or a slip on.

Here are 5 tips to use a steel pipe flange for the first time:

1. Use Slip-on Flanges In Low-Pressure Services

Slip-on flanges are more preferred by users owing to them being low cost, taking less time to install, and their ease of use. They are used for non-critical low-pressure services like cooling water, fire water, and other non-challenging pipework owing to their strength being 1/3 lower than that of a weld neck flange. The pipe gets welded to the flange bore and hub.

To check how good the slip-on connection is, a simple visual examination, a magnetic particle, or a PT test are the approaches you can follow. You can use slip-on flanges for pipes with a size greater than NPS 2 ½ (DN 65).

2. Use Socket Weld Flanges In High-Pressure Pipe Works

When doing high-pressure pipe works that are below 2 inches (DN50), socket weld flanges are more preferred. You fillet weld the pipe to the socket weld flange hub. Good welding experience is vital to making this connection since a radiographic examination on the fillet weld is not easily executable.

If, however, the connection is critical and visual examination alone won’t be enough, you can carry out liquid penetrant or magnetic particle tests to check the strength of the connection.

3. Use Lap Joint Flanges In High-Cost Material Pipelines

Lap joint connections work well for pipelines that are in high-cost materials such as nickel alloys and stainless steel as it greatly reduces the total cost or all the flanged connections that are needed.

A lap joint connection is made by combining the stub end which has been welded onto the pipe and the lapped flange or backing flange. You can, for instance, use a stainless steel stub end combined with a carbon steel lap joint flange to get a good welded connection at a very cheap cost. Lap joint flanges generally have a raised face and are often sealed with a flat ring gasket.

4. Connect Weld Neck Flanges To A Butt Weld Pipe For Better Performance

There is a tapered hub on the weld-neck flanges with an end that’s butt weld that can be connected to a butt weld pipe. You can examine the quality of the weld using radiography, ultrasound or you can do it visually.

The welded connection of a pipe and a weld neck flange features good fatigue as well as mechanical stress performance.

5. Ensure That A Skilled Professional Executes Pipe Flange Joints

Trained personnel should be the ones to execute flange joints to prevent any dangerous leakages from happening in the pipeline. As steel pipe flanges are being used for the first time, a properly trained engineer should be the one to execute the flanged joints.


With these 5 tips, you’re all set to use a steel pipe flange. Here’s more information you need to know about steel flange.