INWARD INSPECTION
Check for possible damages during transit when an Expansion Joint is received at site.
Check for broken hardware, loose shipping bars, dents and scratches.
Check the container for Gaskets, Fasteners, Removable Liners and any other components which form a part of Expansion Joint assembly
LIFTING & HANDLING
Lift only with designated lifting lugs.
Do not use chains or any other handling devices directly on Bellows element or Bellows Cover.
Do not use Shipping bars (painted in yellow) to lift the Expansion Joint. They are not designed to lift the Expansion Joint.
Never lift an unrestrained Bellows / Expansion Joint. Doing so will result in damage and the unit will fail in service.
For Expansion Joints not provided with lifting lugs (less than 250 kgs.) the best lifting method should be evaluated at the time of installation.
Do not remove the shipping bars (painted in yellow) till the completion of installation including all pipe restraints.
CARE DURING INSTALLATION :
Ensure adequate care to prevent Dents & Score Marks on thin Bellows.
Safe guard the Bellows from arc strike and weld spatter.
Keep the Bellows free from corrosion. Certain chemicals, dirt and metal filings will damage the Bellows material.
Do not use cleaning chemicals such as soap, detergents and solvents containing chlorides, caustics or sulphides.
They can lead to stress corrosion and will be known only after sometime after put into the operation.
Use only chloride free insulation material if insulation of Expansion Joints is required.
The area should be free of any sharp objects or protrusions. If not removable, they should be notified so that they can be avoided.
The edges of the connecting pipes should be clean, smooth and parallel to each other. Lift the Expansion Joint using the lifting lugs and position into piping.
Orient the Expansion Joint with flow arrow pointing in direction of flow when there is a presence of Sleeve / Flow Liner.
Orient the Flanges of Expansion Joint so that the bolt holes are aligned with pipeline flanges in the case of Expansion Joints with flange ends.
Do not force / rotate the Expansion Joint to match the bolt holes of the mating flange. This will cause torsion on the Bellows and will severely reduce the Bellows capability and may cause premature failure.
It is good practice to leave one pipeline flange loose until the Expansion Joint is installed.
Install gaskets and bolt to the required torque recommended by the flange manufacturer.
Do not entertain the movement of the Expansion Joint (Compression, Extension, Offset and Rotation) due to piping misalignment which has not been anticipated and considered in the design.
The most common installation error is forcing the Bellows to fit an excessive, beyond- construction-tolerance gap in the piping. Any misalignments of greater magnitude will result in premature failure of Bellows.
Ensure that construction personnel make the piping fit the Expansion Joint and not vice versa.
Installation of Anchors, guides and pipe supports shall be in strict accordance with the piping system drawings.
Any field variances from planned installation may affect proper functioning of the Expansion Joint and must be brought to the attention of competent design authority for resolution.
LSI-Mech Engineers Pvt. Ltd. has assisted customers in successful installations.
CHECKING PRIOR TO PRESSURE TESTING
A careful inspection of the entire piping systems shall be made with particular emphasis on the following: -
Are anchors, guides and supports installed in accordance with the system drawings?
Is the proper Expansion Joint in the proper location?
Is the Expansion Joint’s flow direction and pre-positioning correct?
Have all of the Expansion Joint shipping devices been removed?
Are all guides, pipe supports and the Expansion Joints free to permit pipe movement?
Has any Expansion Joint been damaged during handling and installation?
Is any Expansion Joint misaligned? Measuring the Joint overall length, inspection of the convolution geometry and checking clearances at critical points on the Expansion Joint and at other points in the system can determine this.
Are the Bellows and other movable portion of the Expansion Joint free of foreign material?
LINE TESTING
Inspect the entire system to ensure proper installation of anchors, guides and pipe supports in strict accordance with piping system drawings.
Remove shipping bars (painted in yellow) prior to pressure testing once the pipe line anchors, guides and pipe supports are in place.
Pressurise and test the line with Expansion Joint.
Some water may remain in the Bellows convolutions after the test. If this is detrimental to the Bellows or system operation, work out the ways to remove such water.
Do not subject the Expansion Joint to test pressure higher than the specified.
Use water for pressure test free of chloride.
If the system has been designed for a gas, and to be tested with water, Check whether any provision has been made to support the dead weight.
Provide additional support due to the weight of water, if not there.
CHECKING DURING PRESSURE TESTING
Extreme care must be exercised while inspecting any pressurized system or component.
A visual inspection of the system shall include checking for the following: -
Check the evidence of leakage or loss of pressure.
Check for Distortion or Yielding of anchors, Expansion Joint hardware, the Bellows and other piping components.
Check for any unanticipated movement of the piping due to pressure.
Check for Evidence of instability (Squirm) in the Bellows.
Check for the evidence of binding of the Guides, Expansion Joints and other movable parts of the system.
Check for any evidence of abnormality or damage, the same shall be reviewed and evaluated by competent design authority.
CHECKING AFTER SYSTEM COMMISSIONING
Perform a visual inspection and ensure that the thermal expansion is being absorbed by the Expansion Joints in the manner for which they are designed.
Check the Bellows Expansion Joints for evidence of any unanticipated vibration.