What is Pipe Joint?- Types, and Their Application

What is Pipe Joint?

Pipe joints are integral to any piping system because it is not possible to have a continuous length of pipe for a pipe network. These joints can make or break a pipeline system depending on the resulting durability of the technique used to form the joint.

There are different materials of pipes use in the pipeline industry depending on the need and the type of product that will be conveyed through the pipe.

Types of Pipe Joints

The pipes are usually connected to vessels from which they transport the fluid. Since the length of pipes available is limited, therefore various lengths of pipes have to join to suit any particular installation. There are various forms of pipe joints use in practice, but the most common of them are discussed below.

Different types of pipe joints used in the plumbing systems are as follows.

1. Socket or a coupler joint

The most common method of joining pipes is by means of a socket or a coupler. A socket is a small piece of pipe thread inside. It screwed on halfway on the thread end of one pipe and the other pipe then screwed in the remaining half of the socket.

In order to prevent leakage, jute or hemp wound around the threads at the end of each pipe. This type of joint mostly used for pipes carrying water at low pressure and where the overall smallness of size is most essential.

Types of pipe joint

2. Nipple joint

In this type of joint, a nipple is a small piece of pipe threaded outside screwed in the internally threaded end of each pipe. The disadvantage of this joint is that it reduces the area of flow.

3. Union joint

In order to disengage pipes joined by a socket, it is necessary to unscrew pipe from one end. This is sometimes inconvenient when pipes are long. The union joint, provide the facility of disengaging the pipes by simply unscrewing a coupler nut.

4. Spigot and socket joint

It is chiefly used for pipes that are buried in the earth. Some pipelines are laid straight as far as possible. One of the important features of this joint is its flexibility as it adapts itself to small changes in level due to settlement of earth which takes place due to climate and other conditions.

In this type of joint, the spigot end of one pipe fits into the socket end of the other pipe. The remaining space between the two is filled with a jute rope and a ring of lead. When the lead solidifies, it is caulked in tightly.

5. Expansion joint

The pipes carrying steam at high pressures are usually joined by means of an expansion joint. This joint is used in steam pipes to take up the expansion and contraction of pipelines due to changes in temperature.

In order to allow for a change in length, steam pipes are not rigidly clamped but supported on rollers. The rollers may be arranged on wall brackets, hangers or floor stands. The expansion bends are useful in a long pipeline.

These pipe bends will spring in either direction and readily accommodate themselves to small movements of the actual pipe ends to which they are attached.

6. Flanged joint

It is one of the most widely used pipe joints. A flanged joint may be made with flanges cast integral with the pipes or loose flanges welded or screwed. Two cast-iron pipes with integral flanges at their ends.

The flanges are connected by means of bolts. The flanges have seen standardized for pressures up to 2 N/mm2. The flange faces are machined to ensure the correct alignment of the pipes.

The joint may be made leakproof by placing a gasket of soft material, rubber, or canvass between the flanges. The flanges are made thicker than the pipe walls, for strength. The pipes may be strengthened for high-pressure duty by increasing the thickness of the pipe for a short length from the flange.

For even high pressure and for large diameters, the flanges are further strengthened by ribs or stiffeners. The ribs are placed between the bolt holes.

7. Hydraulic pipe joint

This type of joint has oval flanges and is fastened by means of two bolts. The oval flanges are usually used for small pipes, up to 175 mm in diameter. The flanges are generally cast integral with the pipe ends.

Such joints are used to carry fluid pressure varying from 5 to 14 N/mm2. Such high pressure is found in hydraulic applications like riveting, pressing, lifts, etc. The hydraulic machines used in these installations are pumps, accumulators, intensifiers, etc.


What is a pipe joint called?

The pipes having plain ends are joined by fixing fittings at their ends, and such a joint is called a compression joint. The pipe ends are joined with threaded fittings or couplings.

What are the types of pipe joints?

Different types of pipe joints used in the plumbing systems are as follows.

  • Threaded joint.
  • Brazed joint.
  • Soldered joint.
  • Welded joint (butt welded, socket welded)
  • Flanged joint.
  • Compression joint.
  • Grooved joint.

Which is the most common joint in piping?

Butt-welded pipe joints are the most common for pipes in large commercial, institutional and industrial systems. Skilled pipe welders and fitters are required for butt welding. Butt-welded pipe joints provide extremely good strength and leakage integrity.

What joins two pipes together?

Pipe fittings, also known as pipe connectors, attach one pipe to another in order to lengthen the run or change the flow direction in a plumbing system. These are used to combine, divert or reduce the flow of the water supply, and they come in a variety of sizes to fit the pipe they will connect.

What Is Plumbing Joint?

Pipes are connected with the help of joints. A variety of joints are used in the assembly of pipes. Connecting two or more pipes together is called a fitting. Joints are also used for multiple pipe connections and are an important component of the plumbing system.

What are the 4 types of joint?

What are the different types of joints?

  • Ball-and-socket joints. Ball-and-socket joints, such as the shoulder and hip joints, allow backward, forward, sideways, and rotating movements.
  • Hinge joints.
  • Pivot joints.
  • Ellipsoidal joints.

How pipes are joined?

Pipes are commonly joined by welding, by using pipe threads, or by using a mechanical coupling. Process piping is usually joined by welding using a TIG or MIG process. The most common process pipe joint is the butt weld.

How pipes are connected?

The most common joining method for these systems is solvent welding, where the plumber uses a two-part system; a cleaning primer is applied first to the jointing area, which is then followed by the application of a solvent glue. The two pipes and fittings are then pushed together to form a seal.

What is spigot and socket?

The end connection of a fitting that is to be assembled into another fitting is called the “Spigot.” The spigot end of a fitting has the same outside diameter as pipe. The common female connection of PVC fittings is referred to as the socket or hub, and the spigot end of a fitting can be inserted into a Hub or Socket.

What is a spigot joint?

A spigot joint is a type of pipe fitting that is inserted into another pipe fitting. The spigot end typically has the same outer diameter as the pipe and is usually fitted into another larger-diameter joint called a bell.

What are the 4 types of plumbing?

5 Main Types of Plumbing Pipes Used in Homes

  • PEX.
  • PVC.
  • Rigid Copper.
  • ABS.
  • Flexible.
  • Steel and Cast Iron.

How do you join a pipe without welding?

Especially for pipe dimensions of single digit inches, several ways of connecting pipes without welding are possible. Let’s have a look at the most popular alternatives: cuttings rings, flaring, radial press fittings and fipeing.

What is an elbow joint in plumbing?

An elbow is installed between two lengths of pipe (or tubing) to allow a change of direction, usually a 90° or 45° angle; 22.5° elbows are also available. The ends may be machined for butt welding, threaded (usually female), or socketed. When the ends differ in size, it is known as a reducing (or reducer) elbow.

What is pipe expansion joint?

A rubber pipe expansion joint is a flexible connector of two pipes. It provides stress relief in a piping system due to thermal and mechanical vibration or movements. Retaining Ring – Used to compress the expansion joint flange to the mating flange to create a seal. Also called clamp bars or backing bars.

What is the best type of plumbing pipe?

Copper pipes are probably the most traditional plumbing pipe used due to their extensive duration and reliability. They provide superior corrosion resistance, great material to be used for hot and cold water, and it can be managed easily.

What are sockets in pipe?

A Socket Weld is a pipe attachment detail in which a pipe is inserted into a recessed area of a Valve, fitting or flange. In contrast to buttweld fittings, Socket Weld fittings are mainly used for small pipe diameters (Small Bore Piping); generally, for piping whose nominal diameter is NPS 2 or smaller.

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