Home > About Us> Tech & Service

What Are Expansion Joints?

Expansion joints are designed to safely absorb the movement in pipework systems due to heat-induced expansion and contraction of pipework.

Pipe Expansion Joints

Pipe expansion joints are also known as compensators, as they 'compensate' for the thermal movement.

Pipe expansion joints are necessary in systems that convey high temperature commodities such as steam or exhaust gases, or to absorb movement and vibration. A typical type of expansion joint for pipe systems is a bellows which can be manufactured from metal (most commonly stainless steel), plastic (such as PTFE), or an elastomer such as rubber.

A bellows is made up of a series of one or more convolutions, with the shape of the convolution designed to withstand the internal pressures of the pipe, but flexible enough to accept the axial, lateral, and/or angular deflections. Expansion joints are also designed for other criteria, such as noise absorption, anti-vibration, earthquake movement, and building settlement.

Piping Expansion Joint Construction
Piping Expansion Joint Construction

Tube – A protective, leak proof lining made of synthetic or natural rubber. The tubes primary function is to eliminate the possibility of materials being handled penetrating the carcass.

Carcass – The carcass or body of the expansion joint consists of fabric, and when necessary metal.

Cover – The exterior surface of the joint.

Fabric Reinforcement – The carcass fabric reinforcement is the flexibility and supporting member between the tube and cover.

Metal Reinforcement – Wire or solid steel rings imbedded in the carcass, often used for strengthening.

Retaining Ring – Used to compress the expansion joint flange to the mating flange to create a seal. Also called clamp bars or backing bars. Applies to most all expansion joints.

Mating Flange – Used to connect the pipe joint to the pipe in which it is being installed.

Control Rod – Used to limit the axial movements during operation, and prevent the joint from exceeding its movement capabilities. The rods attach the mating flange and expansion joint. Typically used on piping joints, but can be installed on most any joint when required.

Expansion joints are an assembly designed to safely absorb sound, expansion, con traction and vibration to ensure expansion jointsthat the application stays in fully working order.

When we apply this technique to pipe systems, we brand the term ‘pipe expansion joint’ or ‘bellows’.

These pieces of equipment are used in pipe work where movement, thermal expansion and much more could cause problems. The pipe expansion joints are made up from one or more convolutions, which are designed to move or expand to relieve the stress from the solid pipe. The amount of movement or expansion within the application will determine the number and shape of convolutions required. Expansion joints can be manufactured from a range of different materials, from stainless steel and PTFE, to rubber.

Pipe expansion joints are also designed for other criteria, such as noise absorption, anti vibration, earthquake movement and building settlement. Metal expansion joints have to be designed according to rules. Pipe expansion joints are used in a number of industries, including; oil, petrochemical and paper industries.

Pipe expansion joints are often manufactured to withstand temperatures from minus 300°F, up to 4000°F, as well as being able to resist at full vacuum or 2000 psig. Expansion joints can be manufactured from a range of different materials aforementioned. Before the introduction of pipe expansion joints, engineers were battling with the task of combating problems regarding thermal expansion, corrosion and abrasive factors that took effect on the functionality of various applications. Fabric joints can be used in a number of applications for turbines and pipelines, which can defend against resistance, heat and a range of other environmental factors.

Pipe expansion joints are crucial components in the pipe technology sector, which serve a huge number of industries. They are used to counterbalance length changes that generally occur in pipelines from temperature changes and can also absorb vibrations. It is a cost effective solution to increase the life span, reliability and costs of many applications through equipment and process management.




Tech & service

Recommended products
Pipe fittings
Pipe fittings are used to connect pipes.
Welded steel pipes Weld steel pipes
We produce an extensive selection of weld steel pipe
Welded steel pipes Anti corrosion pipe
Anti-corrosio pipe is processed through the preservation
Ceramic-Lined Pipes
from a single spool piece to complete piping systems.
Pipe flanges
Pipe flange are a method of connecting pipes, valves.
Pipe Fitting Accessories
We are passionate in Stub Ends, Bolt Sets, Fasteners
Sunny Steel Blog


About Sunny Steel

Our team are highly trained and experienced in servicing and producing all types of steel supplies. Whether you've got a large construction project, or need parts for industrial machinery, our team of steel fabrication consultants will ensure that your project is provided with the parts you need, when you need them.