The successful installation of expansion joints in a pipe system requires the careful consideration of many variables.
The most important issue is to establish the direction in which the movements are acting and in which way the movements should be absorbed. Once this information is known, the solution incorporating the most suitable expansion joint type(s) can be determined.
The most important issue is to establish the direction in which the movements are acting and in which way the movements should be absorbed. Once this information is known, the solution incorporating the most suitable expansion joint type(s) can be determined.
Fix points and guides for axial expansion joints⬇️
It is important that the fix point is placed as close to the axial expansion joint as possible. It is important to note that only one axial expansion joint can be installed between two fix points. The distance between the expansion joint and the first guide should be a maximum of 4 x diameter. The distance between the following guides should be 14-20 x diameter.
This is illustrated in the drawings below.
It is important that the fix point is placed as close to the axial expansion joint as possible. It is important to note that only one axial expansion joint can be installed between two fix points. The distance between the expansion joint and the first guide should be a maximum of 4 x diameter. The distance between the following guides should be 14-20 x diameter.
This is illustrated in the drawings below.
For other expansion joint types, the position of fix points and guides are dependent on the pipe system and the position of the expansion joint in the pipe system.
AXIAL Expansion joint selection⬇️
This illustrates the importance in the use of the three fix points, as the use of two or more axial expansion joints in a piping section will create an undetermined arrangement.
The amount of movements imposed on each expansion joint is not controlled, as the pipe between the two bellows can move sideward freely in both directions depending on the friction of the pipe supports and the di Rerences in stiRness between the bellows. It is always important to have one axial expansion joint between two fix points.
This illustrates the importance in the use of the three fix points, as the use of two or more axial expansion joints in a piping section will create an undetermined arrangement.
The amount of movements imposed on each expansion joint is not controlled, as the pipe between the two bellows can move sideward freely in both directions depending on the friction of the pipe supports and the di Rerences in stiRness between the bellows. It is always important to have one axial expansion joint between two fix points.
⬆️⬆️⬆️⬆️The piping system should be divided into sections by means of fix points, guides or restraining tie rods in order to have only one expansion joint per section of straight pipe system. The fix points and other restraining devices should be designed for the full pressure thrust from the bellows eRective area plus the bellows displacement force. Additionally, the forces generated by the friction within the guides should also be considered.
⬆️⬆️⬆️⬆️Typifies good practice in the use of a single expansion joint to absorb axial pipeline expansion.
Note the use of one expansion joint between the two fix points, the distance between the expansion joint and a fix point, the proximity of the first guide (G1), the spacing between the first guide and the second guide (G2), and the spacing of guides (Gn) along the remainder of the pipe system.
Note the use of one expansion joint between the two fix points, the distance between the expansion joint and a fix point, the proximity of the first guide (G1), the spacing between the first guide and the second guide (G2), and the spacing of guides (Gn) along the remainder of the pipe system.
⬆️⬆️⬆️⬆️Typifies good practice in the use of expansion joints to absorb axial expansion in a pipe system with a branch connection. The fix point at the junction, which in this case is a tee, is designed to absorb the thrust from the expansion joint in the branch line. Note the proximity of each expansion joint to a fix point, the closeness of each first guide (G1), the spacing between the first guide (G1) and the second guide (G2) and the spacing of guides (Gn) along the remainder of each pipe section.
Flexible rubber expansion joints⏬
Flexible rubber expansion joints are a key part in piping systems, since they provide the necessary flexibility to absorb system dynamics associated with vibration, temperature and pressure changes within the pipeline. Therefore, the careful material and design selection of flexible rubber expansion joints for a given application, as well as properly engineered installation, are so important factors for determining performance. By routine inspections, we can easily check the signs of fatigue and premature failure in the flexible rubber expansion joint s, long before the actual failure occurs.
Flexible rubber expansion joints are a key part in piping systems, since they provide the necessary flexibility to absorb system dynamics associated with vibration, temperature and pressure changes within the pipeline. Therefore, the careful material and design selection of flexible rubber expansion joints for a given application, as well as properly engineered installation, are so important factors for determining performance. By routine inspections, we can easily check the signs of fatigue and premature failure in the flexible rubber expansion joint s, long before the actual failure occurs.
Rubber expansion joints have been specified and successfully used for many years to accommodate pressure loads, relieve movement stresses, reduce noise, isolate vibration, compensate for misalignment after plants go on stream and prolong the life of pumps and other motive equipment. Once in service, the flexible rubber expansion joint should be protected from any ozone generating processes such as nearby welding. Proper storage in a cool dry location prior to installation will help lengthen service life.