Socket Weld Fittings have pipe attachment detail in which a pipe is inserted into a recessed area at the end of the fitting. They are mainly used for small pipe diameters. Commonly used in low-cost, noncritical applications such as domestic water, fire protection, and industrial cooling water systems. Socket Weld fittings are normally made of cast gray or malleable iron, cast brass or bronze or forged alloy and carbon steel.

All Domestic Socket Weld Fittings are made from material forged and machined in USA. All fittings are supplied with MTR for full traceability.

Forged Carbon Steel Socket weld pipe fitting is considered a high pressure pipe fitting when compared to a malleable iron fitting. 6000 lb pressure class is also called schedule 160 pipe fitting. See the table below for pressure and temperature rating of socket weld pipe fitting including SS & Carbon Steel material.

Table below shows comparison of high pressure pipe fitting to a standard pipe schedule

SS304 - A common standard for stainless steel due to its malleability, high corrosive resistance weld-ability  

Material Sheet

Good afternoon. Today we’re talking about socket weld fitting, and for the purpose of this video, I have a collection of some stainless steel socket weld fitting. This is a socket weld coupling, this is a reducing coupling, this is a half coupling, this is a socket weld 90° elbow, this is a socketweld pipe cap, 45° elbow, socket welded tee, socket weld cross, and a socket weld pipe union. We’ll use a 1 inch pipe for the purpose of demonstration. Again, this is a carbon steel pipe, but we’ll use that for demonstration.

Socket weld pipe fittings are made in a forged carbon steel. They are also made in stainless steel and nickel alloy. Socket weld fittings generally come in three different pressure ratings, a 3000 pound, a 6000 pound, and a 9000 pound pressure class. The most common size of the socket weld fitting is from 1/2 inch up to 4 inch. All of these pressure fittings generally are not used beyond 4 inches. In fact, more common is about 2 inch, 3 inch. You will not see a lot of socket weld fittings in larger than 2 or 3 inch sizes; mostly it’s 1 inch, 1 ½ inch nominal pipe size.

Let’s start with different types of socket weld pipe fittings. This is a socket weld coupling. You take a pipe, you put it in, and you weld it. Socket weld fitting, you actually have to weld it. You weld it right here and then the other side, you weld right here, and that makes a coupling.

This is a socket weld reducing coupling, it’s for a 1 inch pipe here, and it’s for a 3/4 inch pipe right here. I don’t have a 3/4 inch pipe sample, but it allows you to connect a 1 inch pipe to a 3/4 inch pipe or whatever reducing size you’re using. These are reducing couplings.

This is a half coupling and you get a lot of questions, what is the difference between a full coupling and a half coupling? A half coupling, you can only put pipe from one side, that’s it. That’s why it’s called half coupling because you don’t have the other side that you can put the other pipe, so you just weld it right here. It’s a good way that you put it on a pipe or you want an extension to something, so you run that in and then you can do whatever you want to do with the other end. That’s the half coupling.

This is a socket weld pipe cap, you can see it slides here, you weld it right here, and then it caps the pipe. Socket weld pipe cap.

Socket weld 45° elbow, same thing, one pipe right here and the other pipe right here, makes a 45° connection. This is a socket weld 90° elbow, same thing, you slide a pipe here, and you weld it, and make a 90° connection right there. Socket weld tee, the same thing, right here, right here make a T, much like a butt weld fitting.

This is a socket weld cross. If you’re pipe installation requires pipes crossing, or different instruments, coming from four different directions, then you can use a cross. It goes here, goes here, goes here. That’s a socket weld cross.

This is a socket weld union and it goes right here, and then the other side goes right here, then you use that. The benefit of a union is that it’s easy to make a connection. This is how it looks like, there’s the threaded component, there’s a sealing component, you can see it seals on the face right here, and there is a nut that tightens it and it cannot go anywhere. Once you have both sides welded on it, you can make it tight by turning the thread and it pulls it together like this. Imagine a pipe right here, and another pipe right here and you use the union and make a tight connection.

In summary, socket weld fittings are available in forged carbon steel, stainless steel, nickel alloys. They are made as per ASME B16.11. Socket weld fitting comes in a pressure rating of 3000 pound, 6000 pound, 9000 pound. Loosely, they are related to 3000 pound is roughly schedule 80, extra heavy; the 6000 pound is roughly schedule 160. Socket weld fittings are available from 1/2 inch all the way to 4 inch nominal pipe size. They are not very common in larger pipes; most commonly they are used on a 1 inch, 1 ½, up to 2 inch. You will not see a lot of people using a 3 inch or a 4 inch socket weld fitting. That’s it. Thank you.