Pipe expansion joints, also known as expansion compensators or bellows are used in pipe work applications where thermal expansion, movement and vibration could otherwise cause problems. There are many expansion joints for piping. Here is a list of types of pipe expansion joints.
Stainless steel expansion joints
The use of stainless steel expansion joints in a wide range of industrial applications is widespread, including power plant, process, chemical, and petrochemical installations, engine exhaust, steam and thermal fluid distribution, chimneys and flues, and building services pipework.
Pipe expansion joints are typically made out of stainless steel. Stainless steel is a strong material that can withstand lots of movement and impact without being damaged. It’s also corrosion resistant, which allows it to hold up well against harsh conditions like rain and snow, which can be particularly damaging to exposed piping systems. The more movement a pipe experiences due to weather or other forces, the more impact resistant your expansion joint needs to be.
Rubber expansion joints
A rubber expansion joint is a specially designed elastomeric sleeve that has been extruded or moulded to match both pipe outer diameter and overall length. When a rubber expansion joint is installed, it will compensate for any thermal movement or system vibration. These joints are typically rated for 0 to 50 percent linear and lateral displacement.
PTFE expansion joints
There are many industrial applications in which PTFE Expansion Joints are used, especially when the adjacent equipment is fragile or the media is either extremely corrosive or extremely pure.
The pipe-expansion joint is inserted inside a straight run or curve. The length is determined by how much expansion or contraction is expected, with allowances for material and strength loss. The inserts are made from PTFE sheeting (Teflon). One end of each sheet extends to form a bellows shape that grips and supports pipe at many places along its length as it expands and contracts with temperature changes.
Universal expansion joints
A universal expansion joint, also called a u-pipe, is used to allow pipes to expand and contract without causing stress on connecting sections. It’s made up of two concentric pipes that are joined by four sleeves at right angles. This expansion joint has greater resistance than single tube joints, but it will create friction when changing direction. Universal pipe expansion joints come in single or double compensator models. The additional components support more pressure and make them less expensive than piston and bellows models.
Gimbal expansion joints
Pipe expansion joints are devices which absorb and dissipate vibration energy to improve flow. The joint consists of a casing, containing compressed gimbal rings that can expand freely. It provides smooth functioning by controlling pipe movement. This results in better flow in piping systems due to minimised pipe vibration and is used where rigid piping cannot be used. The gimbal junction is also known as bellows compensator, flexible joint or bend compensator.
There are many factors to consider when deciding which pipe expansion joint is best for your application. One of these factors is temperature. Understanding thermal expansion will help you choose a pipe expansion joint that has a working temperature range that fits your needs.