Expansion Joints installation instruction

1) Selection of expansion joint must be done as to handle the expansion amount of the pipeline and according to system
pressure.
ΔL = α.Δt.L1
ΔL = Expansion amount (mm)
α = Pipe termal expansion coeffcient (mm/m°C) (To be selected from the pipe material tables )
Δt = Temperature difference between fluid and assembly (°C)
L1 = Pipe length between two fxed points (m)
Calculated ΔL value positive (+) means expansion, negative (-) means compression at pipe section.
2) Only one expansion joint can be installed between two fxed points.
3) Sliding guide & fxed point allocations should be completed as shown below.
L1: d L4 &L5 values should be selected from
L2: 4d the guide tables of EJMA code system. (Table 1)
L3: 14d

 

 

4) No axial inaccuracies to be exist in the pipeline.
 

 

 

5) Counter flanges should be placed vertically to the pipe axis.
 

 

 

6) Damages caused by arc sparks through welding process should be prevented. Bellows must be protected by a wet towel or cloth during the welding
 

 

 

7) Flow direction should be examined carefully during the installation of expansion joints with inner sleeve.
 

8)  Expansion joints are “zero load” elements, they can’t absorb additional loads. The hole axis of the expansion joint’s flange and counter flange must be matched especially for fxed flanged expansion joints in order to prevent possible torsion loads at the bellows.

9) Bellows of expansion joints are made in stainless steel. Bellows should not be exposed of the mechanical impacts of other equipment.
 

10) Expansion joint must be pre-stressed. The reason for pre-stressing a compensator is that the service life is signifcantly prolonged and the absorption of movements is increased. As the compensators often are installed in cold pipelines they are pre-stressed to absorb larger movements. An example of pre-stressing amount is given below. Half of the total expansion amount may be practically considered.
 

 

11) Pre-sstressing of externally pressurized expansion joints are done during the production. After the installation of expansion joint, pre-setting rods are taken out and the expansion joint gets ready.

12) District heating expansion joints are delivered pre-stressed and this prestressing settles automatically once the plant is commissioned, after the installation. District heating expansion joints are provided at assembly length.

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