What Is Plumbing Joint?
Pipes are connected with the help of various pipe joint types. A variety of joints are used in an assembly of pipes. Connecting two or more pipes together is called a fitting. Various types of joints could be used in a pipe as per the requirement.
Joints, or joint pipe connections, are also used for multiple pipe connections and are an important component of the plumbing system. Generally, the pipe joint fitted can easily sustain the pressure created in the pipe.
Types of Pipe Joint.
- Threaded Joint.
- Brazed Joint.
- Spigot and Socket joint.
- Socket Welded Joint.
- Soldered Joint.
- Welded Joint (Butt Welded, Socket Welded)
- Flanged Joint.
- Compression Joint.
- Grooved Joint.
- Push-Fit Joint.
- Hep2o Joint.
1. Threaded Joint
Threaded joint means, pipes are connected by screwing with the help of threads provided for each pipe. One pipe having internal threads and the other one having threads externally. Cast iron pipes, copper pipes, PVC and G.I pipes are available with threads.
Thread joints are available from 6 mm diameter to 300mm diameter pipes.They are preferable for low temperature, the joints may expand and leaked due to thermal expansion. Installation of threaded joint id easy but good maintenance required.
2. Brazed Joint
Brazed joints are generally used to achieve higher joint strength or fatigue resistance. To accomplish this, filler metals stronger than those composed primarily of tin must be used. However, this increased strength generally comes from filler metals made of materials that melt at higher temperatures.
3. Spigot and Socket joint
What is a spigot? A spigot joint is a type of pipe fitting connection 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 joint called a bell or socket. Together, these two elements form what is commonly known as a bell and spigot joint.
Spigot and Socket Joint: Sometimes this is called bell and spigot joint. This type of joint is mostly used for cast iron pipes. For the construction of this joint, the spigot or normal end of one pipe is slipped in socket or bell end of the other pipe until contact is made at the base of the bell.
4. Socket Welded Joint
It is one of the most common methods of joining pipes used in large infrastructure like a commercial, institutional and industrial systems. The cost of material is low, but the labour costs are more due to the non-availability of trained welders and fitters.
5. Soldered Joint
Soldered joints are material-closed joints (bonds) of two solderable metals. There are different forms of soldered joints. Wire-to-wire joints as parallel, cross or hook joints as well as soldered joints with twisted wires. Parallel and cross joints are mechanically connected by the solder only and, therefore, can be more easily detached.
The joint is heated above the melting-point temperature of the solder by means of the soldering iron and bonded with soldering tin added. Then the soldered joint must cool down with no displacement of the wires.
6. Welded Joint (Butt Welded, Socket Welded)
Groove welded joints, also called butt welds, are weldments that are commonly used when joining similar pipes together. They can also be used to join pipes to valves, fittings, and flanges for a secure attachment. For piping of certain thickness, the pipe may be cut at a sloping right angle before being welded.
7. Flanged Joint
A flange is a method of connecting pipes, valves, pumps and other equipment to form a piping system. It also provides easy access for cleaning, inspection, or modification. Flanges are usually welded or screwed. Flanged joints are made by bolting together two flanges with a gasket between them to provide a seal.
8. Compression Joint
A compression fitting is a fitting used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. In instances where two pipes made of dissimilar materials are to be joined, the fittings will be made of one or more compatible materials appropriate for the connection.
9. Grooved Joint
When two pipes are joined together by making grooves (narrow cuts or depression) at the end of pipes with the help of sockets or couplings, such joints are called grooved joints. Due to the ease of assembly of the grooved joints, the labour cost is less. The piping system can be easily uninstalled and reinstalled frequently for maintenance. These are mostly used for fire protection.
10. Push-Fit Joint
This type of joint features a toothed ring to grip the pipe and a rubber O-ring to create the seal. The end of the copper (or plastic) pipe is pushed into the joint until it hits the internal stop in the middle.
The joint can be pulled apart by pushing the ring against the joint and slowly pulling to pipe out. Push-fit joints are very quick, easy and reliable to use, but cannot be used for all applications (such as connecting directly to a boiler).
11. Hep2o Join
Hep2o joints are similar to compression joints but designed specifically for use with polybutylene pipes (although they can be used on copper pipes).
The pipe is pushed into the end of the joint and the cap nut is tightened, compressing the internal grab ring. Hep2o joints can be reused, but you need a special tool to release and remove the grab ring. Supplied with a pipe insert to protect the walls of polyethene pipes. Expensive and more bulky than other types of joint.
Different Types of Pipe Joints and Where Are Use?
| Sr.No. | Types of Pipe Joints | Where Are Use |
| 1 | Threaded Joint. | Cast iron pipes, copper pipes, PVC and G.I pipes are available with threads |
| 2 | Brazed Joint. | Generally used to achieve higher joint strength, Brazing is a joining process traditionally applied to metals (but also to ceramics) |
| 3 | Spigot and Socket joint. | Cast iron commonly used for potable water transmission and distribution |
| 4 | Socket Welded Joint. | small pipe diameters (Small Bore Piping); generally for piping whose nominal diameter is NPS 2 or smaller |
| 5 | Soldered Joint. | Used to joint copper and copper alloy pipes |
| 6 | Welded Joint (Butt Welded, Socket Welded) | Used to join pipes to valves, fittings and flanges for a secure attachment. |
| 7 | Flanged Joint. | Flanged joint design means that pipes are secured by external screws, providing additional joint support for the transportation of substances at high pressure. |
| 8 | Compression Joint. | Â used in plumbing and electrical conduit systems to join two tubes or thin-walled pipes together. |
| 9 | Grooved Joint. | Grooved pipe couplings can employ one of two basic styles: flexible or rigid |
| 10 | Push-Fit Joint. | They are fully waterproof thanks to the neoprene O-rings inside them. Push-fits are the quickest, easiest way to fit a joint – particularly for the DIYer who may not have a lot of plumbing experience. |
| 11 | Hep2o Joint. | Use in domestic water distribution and central heating systems including pressurised systems and combination boilers in accordance |
FAQs About Plumbing Joints
What is a plumbing joint?
A plumbing joint is a connection between two or more pipes, created using various types of fittings. These joints are essential for assembling pipes and ensuring a leak-proof, pressure-sustaining plumbing system.
What types of materials can be used for threaded joints?
Threaded joints can be used with cast iron pipes, copper pipes, PVC pipes, and galvanized iron (G.I.) pipes.
What are the advantages and limitations of threaded joints?
- Advantages: Easy to install, available in a wide range of diameters (6 mm to 300 mm).
- Limitations: Not suitable for high temperatures due to potential thermal expansion and leaks.
Why are brazed joints used?
Brazed joints are used to achieve higher joint strength or fatigue resistance. They require filler metals that melt at higher temperatures for increased strength.
What is a spigot and socket joint?
A spigot and socket joint, also known as a bell and spigot joint, involves inserting the spigot end of one pipe into the socket or bell end of another pipe. This type of joint is commonly used for cast iron pipes.
Where are socket welded joints commonly used?
Socket welded joints are frequently used in large infrastructure systems such as commercial, institutional, and industrial setups, especially for small pipe diameters (NPS 2 or smaller).
What are soldered joints, and where are they used?
Soldered joints are created by heating the joint above the melting point of the solder, bonding two solderable metals. They are typically used to join copper and copper alloy pipes.
What is the difference between butt welded and socket welded joints?
- Butt Welded Joints: Used for joining similar pipes and connecting pipes to valves, fittings, and flanges.
- Socket Welded Joints: Typically used for small pipe diameters and require inserting the pipe into a socket before welding.
How do flanged joints work?
Flanged joints connect pipes, valves, pumps, and other equipment in a piping system by bolting together two flanges with a gasket between them to provide a seal. They offer easy access for cleaning, inspection, or modification.
What are compression joints, and where are they used?
Compression joints are used to join two tubes or thin-walled pipes in plumbing and electrical conduit systems. They are often employed when connecting pipes made of dissimilar materials.
What are the benefits of grooved joints?
Grooved joints are easy to assemble and disassemble, making them cost-effective in terms of labor. They are commonly used for fire protection systems due to their flexibility and ease of maintenance.
How do push-fit joints work?
Push-fit joints use a toothed ring to grip the pipe and a rubber O-ring to create a seal. The pipe is pushed into the joint until it hits an internal stop. These joints are quick, easy, and reliable but not suitable for all applications, such as direct connections to boilers.
What is a Hep2o joint, and where is it used?
Hep2o joints are similar to compression joints but are specifically designed for use with polybutylene pipes, though they can also be used with copper pipes. They are commonly used in domestic water distribution and central heating systems.
