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Why Socket Weld Flange is the most recommended?

Socket weld flange has been around a lot in the industry and people are wondering about the reason for their popularity.

Here in this blog, we will dive deep into learning about socket weld flanges. Before anything, let’s first understand its meaning and, how it is distinct from other weld connections.

Meaning of socket weld flange

Socket-weld pipe flanges are typically useful on smaller sizes of high-pressure pipes. These pipe flanges are attached by inserting the pipe into the socket end and applying a fillet weld around the top. It allows for a smooth bore and better flow of the gas or fluid inside the pipe.

Slip-on pipe flange with a hub is a more common connection that comes with published specifications that range from ½” thru 24”.

Socket weld pipe flanges are usually provided with an RTJ facing, flat face, or raised face. When a raised face is necessary for socket weld pipe flanges, the standard height is 1/16” for socket weld pipe flanges under 400#. For socket weld pipe flanges of 400# and up, the standard socket weld pipe flange raised face height is ¼”.

In simple words, a socket weld is a pipe bridging component installed into a recessed area of fitting or flange. The socket can be considered a female member of the joint that harbors the pipe. It is also known as a fillet weld joint as it can be secured by only one fillet.

Applications of socket weld flanges

Socket weld flanges make a good fit for non-critical operations. It is a perfect choice to join small-diameter piping less than 2 NPS. It is not usually usable at daunting pressures and temperatures as it can only resist about half of the forces than that of buttweld.

These possess characteristics where it holds leakage resistance very high along with moderate structural strength. It is why, industries that carry dangerous, toxic liquids employ socket weld fittings.

Apart from this, it has moderate pressure tolerates that may help rank better than tee joint, edge joint, or lap joint. Therefore, it is preferably adopted in pressure conditions lesser than 600 psi. Along with slip ons, these socket connections do not exist per ASME/ANSI B16.5 in 2500# class

Useful in several industrial operations

Good calibration since the fitting is fixed and no additional fastening is required. As it does not require exclusive preparation to secure connections, the costs are cut down to half compared to the butt weld joints.

Apart from that socket weld also offers high strength. Thereby, it is leakage-proof compared to any other type of connection. A socket weld can be either a raised face or a flat-face linkage.

Advantages of Socket weld flanges

Here are some advantages of socket weld flanges:

  • It can replace the threaded flange to minimize the risk of leakage.
  • It doesn’t require beveling before welding.
  • Welding work outside the pipe won’t penetrate the pipe bore.
  • It is recommended for applications where internal welding operations are tough. The sock-welded construction eliminates internal pockets while avoiding the warpage of welding heat and damage to the flange face caused by the weld spatter. It also has the same internal pressure as the sliding on the flange with better fatigue life.

Downsides of socket weld flanges

The only bargain here is that the socket weld flange has a gap requirement of 1.6mm towards the pipe portion that receives the joint, i.e., at the bottom of the pipe.

It is done to compensate for the expansion that happens during the thermal setting at the joint. However, the setting of excess metal at the joint makes the socket weld vulnerable and creates a hotspot for stress at the particular portion.


If you compare socket weld flange to any other weld, you can easily make out why it is relied upon and why its popularity is wide. Texas Flange is one of the leading exporters of a wide range of flanges. If you want to know more about socket weld or any other flange, you can contact us today, and our experts will help you select the best flange as per your preference.


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